Effects of erythromycin in the dog upper gastrointestinal tract G. E. HOLLE, E. STEINBACH, AND W. FORTH Gastroenterological Research Laboratory, Walther Straub Institute for Pharmacology Ludwig Maximilian University, 8000 Munich, Federal Republic of Germany Holle, G. E., E. Steinbach, and W. Forth. Effects of erythromycin in the dog upper gastrointestinal tract. Am. J. Physiol.
263
(Gastrointest.
Liver
Physiol.
26):
G52-G59,
1992.-The effects of erythromycin on motor and electrical behavior of the antrum, pylorus, and duodenumwere determined in chronically instrumented, awake dogs. Erythromycin infusion resulted in an abrupt, powerful increase in motility. The motility index increased l&fold in the antrum, 15-fold in the pylorus, and &fold in the duodenum.Bradyarrhythmia with a 30% decreasein slow-wave frequency occurred in all animals. Retrogradegiant contractions in associationwith retching and vomiting occurred in 88% of the dogs. Neostigmine was less potent than erythromycin in increasing motility. Hexamethonium given intra-arterially during erythromycin infusion abolished motility for 7.2 t 2.9 min and intra-arterial atropine did so for 51 t 25 min. Hexamethonium or atropine restored the electrical slow-wave frequency. The results provide evidence that erythromycin action involves cholinergic pathways including ganglionic transmission. prokinetic drugs; stomach; intestine; gastrointestinal motility MACROLIDE ANTIMICROBIAL AGENTS have been usedin
medical treatment for more than three decades for a wide range of conditions, mainly focal infections attributed to various Gram-positive and Gram-negative aerobic and anaerobic bacteria. One of the most useful macrolide antibiotics has been erythromycin and its chemical modifications. In 1984 two studies dealing with the gastrointestinal side effects of the drug, namely, abdominal cramps, diarrhea, nausea, and vomiting, showed strong stimulation of gastrointestinal contractions (8, 13) on oral and intravenous administration of the drug to dogs. Later work demonstrated that erythromycin dramatically accelerated gastric emptying of a mixed solid and liquid meal (19). Several reports have suggested motilin receptors as the site of action of erythromycin (12, 16). To clarify the actions of erythromycin, the aim of this study was to compare the effects of intravenous erythromycin in the postoperative phase of gastrointestinal motordysfunction with those of neostigmine. In addition we tested the hypothesis that cholinergic pathways are involved in the action of erythromycin. MATERIALS AND METHODS Seventeen healthy mongrel 1-yr old dogsweighing 18-24 kg were used.The dogswere a crossbreedof labrador, sheepdog, and pointer; both malesand females were used. The animals were fed one mealper day consistingof 500g fresh meat for dogs mixed with vegetables enriched with vitamins. Weight was monitored daily and kept constant over the experimental period. After abdominal surgery, the animalswere nourishedby intravenous infusion of 500 ml of concentrated amino acids, electrolytes, and glucose(AKE 1100,Fresenius). After a 24-h fast, the dogs were anesthetized with 2vG52
0193-1857/92
$2.00
and Toxicology,
3’-dimethylaminopropyl-3-propionylphenothiazine phosphate (Combelen,Bayer), 0.5 ml/kg body weight, intramuscularly, and 2.5 mg 1-6-dimethylamino-4,4-diphenyl-3-3 heptanone hydrochloride, 1 mg methyl-4-hydrobenzoate; (Polamivet, Hoechst) maximum 0.5 ml/kg body weight intravenously. NaCl (0.9%) was infused during the operation. Surgeries were performed under aseptic conditions. A gas-sterilized set of five platinum electrodesand sevenstrain gaugeforce transducersconnectedto a 31-pin plug (ITT Cannon Electric, Santa Ana, CA) with Teflon-coated silver wires (Cicoil, Chatsworth, CA) wasimplanted asdescribedearlier (7). The plug waspositioned subcutaneously between the scapulae.Wires were tunneled to the abdominal wall and from there into the peritoneal cavity where the strain gaugesand the electrodeswere suturedto the seromuscularlayer in the transverse axis of the antrum, pylorus, and duodenum. Three miniature strain gauges(R. Bass,Madison, WI) and one electrodewere placed at the pylorus. A 3.5 Fr Groshong silicon catheter (Catheter Technology, Salt Lake City, UT) was installed via the arteria gastroomentalisdextra into the retropyloric arterial supply, and the port wasimplanted subcutaneously in the thoracic region. The following drugswere used.Hexane-1,6-bis[trimethylammonium chloride] (hexamethonium chloride, C&H3&12N2; Sigma, St. Louis, MO) (25 mg/2 ml 5% glucose)was administered via the arterial port system; atropine sulfate (Braun, Melsungen,FRG) (1 mg/l ml H,O) wasadministered via the arterial port system. H,O-soluble erythromycin lactobionate (Abbott, Wiesbaden, FRG) (300 mg/200 ml 0.9% NaCl) was administeredintravenously over 2 h; neostigminemethylsulfate (Prostigmin, Hoffmann-La Roche, Nutley, NJ) (0.5 mg/l ml) wasadministeredintravenously as 2 ml/200 ml 0.9% NaCl over 1 h. Hexamethonium (25 mg) was administered intra-arterially during the interdigestive state 15min beforethe expectedend of phaseII of the migrating myoelectric complex (MMC) and in the digestive state 15 min after food intake. The experimental seriesincluded 17 animals for the interdigestive and the digestive experiments. Hexamethonium was alsoapplied 20-30 min after the beginning of intravenous erythromycin infusion. This seriesincluded nine animals. Atropine (1 mg) was applied intra-arterially with the same time course as hexamethonium. The seriesincluded nine animalsin the digestive state. Atropine wasalsoapplied 20-30 min after intravenous erythromycin infusion was begun. Apart from these experiments, erythromycin or Prostigmin was given intravenously in the first few days after operation. These experiments included 15 animals that received erythromycin alone and 14 animals that received Prostigmin alone. During all the pharmacological experiments, gastrointestinal motility was recordedover at least a 10-h period. Protocols. All 17 animalswere usedin the erythromycin experiments, and 15 of them were used in the Prostigmin experiments.In nine animalsof the first group, hexamethonium was administered intra-arterially in addition. In a further experiment, intra-arterial atropine was administered at different times in nine animals during erythromycin infusion.
Copyright 0 1992 the American Physiological
Soci’ety
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR
EFFECTS
/.
1000’
G53
OF ERYTHROMYCIN
T\ -r
ii ‘0 ,r 800
l V 0
3.;- 600 ii
Antrum Pylorua Duodenum
400
-\+ 1 I
=v
200
nl NaCl
w I
I
Y-w= A
Am
-
0
-60
60
0
120
180 Time
B el
1”
0
300
420
360
min.
Erythromycin i I I
I I
. . . . . .
240
-
. . . . . . . . . . . . .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . .
..J........
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..b
1”
30
1
60
”
1
90
”
. . . . . . . . . . . . . . . . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . ..
1
120
’
11
16
150 time
1
180
”
I”
210
11
240
’
I
270
’
11
11
300
1
330
min.
Fig. 1. A: motility index (MI) calculated from strain gauges in antrum, pylorus, and duodenum before, during (120 min), and after 10 mg/kg of body weight erythromycin infused intravenously over 120 min in 9 dogs. B: motility registration over 330 min in 1 dog before, during, and after 300 mg erythromycin intravenous infusion over 110 min from electrode in distal antrum (el) and from strain gauge force transducers in distal antrum (a2), prepylorically (p6), pylorus minor curvature side (p5), and pars descendens duodeni (d4). Vertical dashed lines, beginning and end of erythromycin administered intravenously.
All motility measurementswere performed in the unanesthetized animal after a 24-h fast over a period of at least 10 h. In experiments done during the interdigestive state, a full cycle of the MMC was registered at the onset. If no MMC was seen, which was mostly the casein the early postoperative state, at
least 150 min of recording elapsedbefore erythromycin or Prostigmin infusion was started. In the digestive state, a meal of 280 g meat wasgiven after a full MMC cycle or after at least 150 min of interdigestive motility had beenrecorded.In the interdigestive experimentswith
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
G54
MOTOR
EFFECTS
OF ERYTHROMYCIN
the highest physiological contraction by at least 25%. MI was calculated for each phaseand condition, and mean values were expressedper hour. In the digestive state, MI was calculated for each 15-30 min and then averagedin stepsof 1 h over the whole period. Slow waveswere calibrated by the Hellige AC amplifier, and amplitude was given in microvolts and millivolts. Frequency was calculated by visual inspection. The number of contractions was related to the number of slowwavesin the given time period and expressedascontractile activity percentage.Paired Student’s t test wasusedfor statistical analyses (P < 0.05 indicated significant difference), and data are expressedas meanst SD.
1000 900 800 0
Duodenum
700 ii 600 ‘D -c h 500 .-w -.; 400 I 300 200
RESULTS
100 0 -60
0
60
120
180 Time
240
300
360
420
(min)
Fig. 2. MI calculated from strain gauges in antrum, pylorus, and duodenum before, during (120 min), and after 0.5 mg neostigmine intravenous infusion in 5 dogs.
6F
Hexamethonium
P 1
I
1
phase
I
t MMC
t t Erythromycin -I
post
drugs
2h
m 1
0
t b
’
I
II
III
IV
Fig. 3. Slow-wave frequency in gastric antrum of 9 dogs. I, interdigestive state; II, after intravenous erythromycin infusion (300 mg/200 ml 9% NaCl over 2 h); III, after hexamethonium (25 mg) intra-arterially to the pylorus, during erythromycin infusion (20-30 min after beginning); IV, 15 min after stopping erythromycin infusion.
hexamethonium alone or atropine alone, the drug was applied intra-arterially either 15 min before the expectedend of phaseII of the MMC or 15 min after food in the digestive state. When hexamethonium or atropine was administered during erythromycin or Prostigmin infusion, administration occurred 36 min after erythromycin was started. Controls consistedof either the solvent for the drugs or 0.9% NaCl administered in identical volumes as the drug-containing solutions. The strain gaugeswere connectedto Wheatstone half-bridges (Vishay Micro-Measurements) and the electrodesto Hellige AC amplifying system(time constant 7 = 0.1-0.3 s). All signalswere recorded on an eight-channel rectilinear recorder. Recording was continued for at least 10 h. Data obtained from the force transducersand from the electrodes were analyzed as follows: amplitude of contractions was graded as 1, 2, 3, 4, or 4*, and the motility index (MI) was calculated from the formula MI = (x, X 1) + (x, X 2) + (x, X 4) + (x4 x 8), where x representsthe number of contractions and 1, 2, 4, and 8, their force range. Grade 4 contractions occur mainly during phaseIII of the MMC. The force rangefor grade 1 was -5-10 g; for grade 2, -10-20 g; for grade 3, -20-40 g; and for grade 4, ~40-80 g (10). Grade 4” contractions exceed
Erythromycin or Prostigmin administration. In the first few days after surgery, motility was diminished in the stomach and duodenum. In phase II of the MMC, MI was 63 t 38 in the gastric antrum, 94 t 34 in the pylorus, and 151 t 155 in the duodenum. Intravenous infusion of 300 mg erythromycin over 2 h resulted in a sudden MI increase to 1,096 t 286 in the antrum, 1,446 t 237 in the pylorus, and 1,260 t 410 in the duodenum. This represented a 17-fold increase in the motility of the antrum, a 15-fold increase in the pylorus, and an &fold increase in the duodenum (Fig. 1). Whereas erythromycin took effect very rapidly, within a few minutes after commencement of the infusion, the reaction to Prostigmin was slower, reaching the full effect, which was 20% less than that of erythromycin, after 20-30 min (Fig. 2). The motor activity produced by erythromycin ceased promptly after infusion stopped, whereas the effect of Prostigmin was still visible over the next 100 min. Erythromycin administration resulted in bradyarrhythmia of a 30% reduction in the frequency of the basic electrical slow waves in the gastric antrum and pylorus (P < 0.001). It decreased the slow-wave frequency from 4.9 t 0.6 to 3.5 t O.O5/min (Fig. 3). In 88% of the experiments with erythromycin, retrograde giant contractions occurred in the duodenum. These were accompanied by retching and to a lesser degree by vomiting. Hexamethonium or atropine alone. Intra-arterial administration of 25 mg hexamethonium close to the pylorus at the end of phase II of the second registered MMC promptly abolished the contractile activity for 8.5 t 5 min. When the blockade finished, motility continued undiminished until the end of the experiment. The MMCcycle in which the hexamethonium was administered was nonsignificantly longer (149 t 60 min) than the one before (124 t 31 min) and the three after, which were irregular in time (104 t 50,120 t 39, and 180 t 104 min). Hexamethonium in the digestive state abolished contractile activity for 11.8 t 7.2 min (Figs. 4 and 5). MI was reduced for 15 min when contractions began to recur and were followed by normal, powerful contractions (Fig. 5). Administration of the solvent alone or of 2 ml 0.9% NaCl intra-arterially had no effect on motility (Fig. 6). When atropine was given 15 min after food, motility in the antrum, pylorus, and duodenum ceased for 44 t 5.8 min and the MI was extremely low in the subsequent 30 min, decreasing from 306 t 134 before atropine to 41 t 25 after the drug in the antrum, from 361 t 249 to 49 t 45
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR
G55
OF ERYTHROMYCIN
hexa methonium 25 mg LA.
F
All
EFFECTS
+
D IV
E3
1
I
---
Fig. 4. Recordings from the digestive state of one dog (15 min after a 280-g meat meal). Hexamethonium (25 mg) in 2 ml 5% glucose close intra-arterially to pylorus. Mechanical activity in antrum (AII), pylorus (PVI, PV, and PVII), and pars descendens duodeni (DIV). Electrical activity in antrum (E2), pylorus (E3), and pars descendens duodeni (E5). Vertical bars at the strain gauges, contraction grade 4 = 80 g; at the electrodes, 350 pV. Contraction activity ceased following hexamethonium for 11.2 min. Short attack of tachygastria can be seen from the electrodes during motility cessation.
---
T ....
hexamethonium 25 mg
TT
antrum pyloric duodenum
*
0
11 Amin
30min
MOmin
>200min
9.2
Fig. 5. MI calculated from strain gauge recordings in antrum, pylorus, and duodenum in 14 14 dogs in digestive state. Hexamethonium (25 mg) administered close intra-arterially to the pylorus 15 min after a 280-g meat meat meal. Motility ceased completely for 11.8 t 7.2 min following hexamethonium infusion.
in the pylorus, and from 341 t 335 to 68 t 103 in the duodenum, representing decreases of 87, 87, and 80%, respectively. Motility never recovered fully from atropine during the course of the experiment (Fig. 7).
Hexamethonium or atropine after erythromycin. When hexamethonium was applied intra-arterially close to the pylorus 20-30 min after the start of erythromycin inf& sion, motility was abolished for 7.2 t 2.9 min. This effect was similar to the results with hexamethonium without erythromycin. After the abolition, motility values remained at the low levels seen before erythromycin stimulation until the end of the experiment. This suggests that the single dose of 25 mg hexamethonium, after a total block of contractile activity for 7.2 min, permanently abolished the stimulatory effect of erythromycin (Fig. 8). Atropine, when given intra-arterially close to the pylorus during intravenous erythromycin infusion, resulted in complete block of contractile activity in the antrum, pylorus, and duodenum for 51 t 25 min. This was followed by MI values resembling those before erythromycin. That persisted until the end of the experiment (Fig. 9). Hexamethonium or atropine restored the electrical slow waves from the condition of bradyarrhythmia seen during erythromycin administration. Hexamethonium increased the basic electrical rhythmic frequency significantly by 48% (P < 0.001) and atropine by 15-20% (Fig.
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
G56
MOTOR 2ml
EFFECTS
gluoose
OF ERYTHROMYCIN
5% I.A.
P VI
El
1
’
,
I
/
I
I
I
, ’
i
’
I
E3
Fig. 6. Control recordings during the digestive state of 1 dog. Solvent (2 ml 5% glucose) was administered close intra-arterially to pylorus 15 min after a meal. Registration from strain gauges and electrodes were identical to those in Fig. 4. No effects were seen after administration of solvent.
atropine 1.0 mg
A meal ’-1
400
--. . . .
I
x $300 l-l R 2200
antrum pylorus duodenum
blockade persisted only for 2 min, and atropine produced a prompt and long-lasting blockade (30-45 min) only in the duodenum. The total blockade in the antrum and pylorus lasted -5 min after a latency period of 6 min.
’
DISCUSSION
l r( 4 0
%oo
0
442 5.8min
30min
>80min
>2OOmin
Fig. 7. MI calculated from strain gauge recordings in antrum, pylorus, and duodenum in 9 dogs in the digestive state. Fifteen minutes after a 280-g meat meal, 1.0 mg atropine was administered close intra-arterially to pylorus. Motility ceased completely for 44 t 5.8 min.
3). With either drug, short (cl-2 min) attacks of tachygastria occurred with slow-wave frequency of lo-12/min in the antrum and pylorus (Fig. 4). This occurred in >50% of the animals. Some of the dogs seemed to be predisposed to this disturbance. Hexamethonium or atropine after Prostigmin. Hexamethonium or atropine had a much weaker effect after Prostigmin administration than after erythromycin. With the dosages described above, hexamethonium
In the present experiment, the powerful excitatory effects of erythromycin on motility of the upper gastrointestinal tract, which was also seen by others (8, 11, 13), was demonstrated by direct measurement of electrical and contractile behavior when the drug was given intravenously over 2 h. Even during postoperative motility disturbances, the drug produced prompt increases in the contractile frequency percentage to values seen during activity phase III of the MMC combined with vigorous enhancement of the MI. This effect exceeded that of Prostigmin, an acetylcholinesterase-blocking drug (6). The motor activity evoked by erythromycin ceased rapidly after the infusion was stopped. This was also observed in humans (15). This is in contrast to the behavior for Prostigmin, in which the motility only slowed down over the next 100 min. Although the erythromycin-initiated contractions were possibly propagated, the increased motility observed after intravenous administration of 10 mg/kg body w-t erythromycin in our experiment cannot be interpreted as phase
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR
EFFECTS
Erythromycin
300
+
G57
OF ERYTHROMYCIN mL1: I.V.
2 h
hexamethonium 25 mg
1500
-
a
-
. . . . I
T
4
I . . . . . . . . . . . . -I--.jt B .A-- I .Am1.1 .
11
Z2.9min
antrum pylorua duodenum
30min
.
l
MOmin
>200min
Fig. 8. MI calculated from strain gauge recordings in antrum, pylorus, and duodenum in 9 dogs before, during (120 min) and after intravenous erythromycin (300 mg) infusion. Hexamethonium (25 mg) was administered close intra-arterially to pylorus 20 min after erythromycin infusion starts. Motility ceased completely for 7.2 t 2.9 min after hexamethonium. Subsequent motility no longer reflects erythromycin effect, despite that infusion was still running.
III of the MMC. Erythromycin in a dosage of 8 mg/kg did not trigger MMCs in humans (15). But with dosages 200min
aline, and pentagastrin. J. Physiol. Lond. 279: 309-320, 1978. 4. Fox, J. E. T., E. E. Daniel, J. Jury, A. E. Fox, and S. M. Collins. Sites and mechanisms of action of neuropeptides on canine gastric motility differ in vivo and in vitro. Life Sci. 33: 817-825, 1983. 5. Gullikson, G. W., H. Okuda, M. Shimizu, and P. Bass. Electrical arrhythmias in gastric antrum of the dog. Am. J. PhysioL. 239 (Gastrointest.
Liver
Physiol.
2): G59-G68,
1980.
6. Holle, G. E. Small intestinal motility disturbances following abdominal surgery. Langenbecks Arch. Chir. Suppl. (Kongressbericht 1991): 324, 1991. 7. Holle, G. E., K. Milenov, and W. Forth. Adrenergic control of interdigestive and digestive motility via the pyloric region. J. Gastrointest. Motil. 3: 131-137, 1991. 8. Itoh, Z., M. Nakaya, T. Suzuki, H. Arai, and K. Wakabayashi. Erythromycin mimics exogenous motilin in gastrointestinal contractile activity in the dog. Am. J. PhysioZ. 247 (Gastrointest. Liver Physiol. 10): G688-G694, 1984. 9. Kim, C. H., F. Azpiroz, and J. R. Malagelada. Characteristics of spontaneous and drug induced gastric dysrhythmia in a chronic canine model. Gastroenterology 90: 421-427, 1987. 10. Ludwick, J. R., J. N. Wiley, and P. Bass. Extraluminal contractile force and electrical activity of reversed canine duodenum. Gastroenterology 54: 41-51, 1968. 11. Otterson, M. F., and S. K. Sarna. Gastrointestinal motor effects of erythromycin. Am. J. Physiol. 259 (Gastrointest. Liver Physiol. 22): G355-G363, 1990. 12. Peeters, T., G. Matthijs, J. Depoortere, T. Cachet, J. Hoogmartens, and G. Vantrappen. Erythromycin is a motilin receptor agonist. Am. J. Physiol. 257 (Gastrointest. Liver Physiol.
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR 20): G470-G474,
EFFECTS
similar
1989.
Pilat, M. A., H. D. Ritchie, H. H. Thompson, and G. P. Zara. Alterations in gastrointestinal motility associated with erythromycin (Abstract). B. J. Phurmacol. 81: 168P, 1984. 14. Sanders, K. M. Role of prostaglandins in regulating gastric motility. Am. J. Physiol. 247 (Gastrointest. Liver Physiol. 10): GlmG126, 1984. 15. Sarna, S. K., K. H. Soergel, T. R. Koch, J. E. Stone, C. M. Wood, R. P. Ryan, J. H. Cavanaugh, H. N. H. Nellans, and M. B. Lee. Effect of erythromycin on human gastrointestinal motor activity in the fasted and fed states (Abstract). Gastroen-
Pharmacol.
13.
terology 16.
96: A440,
1989.
Satoh, T., N. Inatomi, H. Satoh, S. Marni, Z. Itoh, and S. Omura. EM-523, an erythromycin derivative and motilin show
G59
OF ERYTHROMYCIN
17.
contractile Exp.
Ther.
activity
in isolated
254: 940-944,
rabbit
intestine.
J.
1990.
Telander, R. L., K. G. Morgan, D. L. Kreulen, P. F. Schmalz, K. A. Kelly, and J. H. Szurszewski. Human gastric atony with tachygastric and gastric retention. Gastroenterology 75: 497-501,
1978.
Tomomasa, T., T. Kuroume, H. Arai, K. Wakabayashi, and Z. Itoh. Erythromycin induces migrating motor complex in human gastrointestinal tract. Dig. Dis. Sci. 31: 157-161, 1986. 19. Urbain, J. L. C., G. Vantrappen, 3. Janssens, E. Van Cutsem, T. Peeters, and M. DeRoo. Intravenous Erythromycin dramatically accelerates gastric emptying in gastroparesis diabeticorum and normals and abolishes the emptying discrimination between solids and liquids. J. Nuclear Med. 31: 1490-1493, 1990. 18.
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
263
(Gastrointest.
Liver
Physiol.
26):
G52-G59,
1992.-The effects of erythromycin on motor and electrical behavior of the antrum, pylorus, and duodenumwere determined in chronically instrumented, awake dogs. Erythromycin infusion resulted in an abrupt, powerful increase in motility. The motility index increased l&fold in the antrum, 15-fold in the pylorus, and &fold in the duodenum.Bradyarrhythmia with a 30% decreasein slow-wave frequency occurred in all animals. Retrogradegiant contractions in associationwith retching and vomiting occurred in 88% of the dogs. Neostigmine was less potent than erythromycin in increasing motility. Hexamethonium given intra-arterially during erythromycin infusion abolished motility for 7.2 t 2.9 min and intra-arterial atropine did so for 51 t 25 min. Hexamethonium or atropine restored the electrical slow-wave frequency. The results provide evidence that erythromycin action involves cholinergic pathways including ganglionic transmission. prokinetic drugs; stomach; intestine; gastrointestinal motility MACROLIDE ANTIMICROBIAL AGENTS have been usedin
medical treatment for more than three decades for a wide range of conditions, mainly focal infections attributed to various Gram-positive and Gram-negative aerobic and anaerobic bacteria. One of the most useful macrolide antibiotics has been erythromycin and its chemical modifications. In 1984 two studies dealing with the gastrointestinal side effects of the drug, namely, abdominal cramps, diarrhea, nausea, and vomiting, showed strong stimulation of gastrointestinal contractions (8, 13) on oral and intravenous administration of the drug to dogs. Later work demonstrated that erythromycin dramatically accelerated gastric emptying of a mixed solid and liquid meal (19). Several reports have suggested motilin receptors as the site of action of erythromycin (12, 16). To clarify the actions of erythromycin, the aim of this study was to compare the effects of intravenous erythromycin in the postoperative phase of gastrointestinal motordysfunction with those of neostigmine. In addition we tested the hypothesis that cholinergic pathways are involved in the action of erythromycin. MATERIALS AND METHODS Seventeen healthy mongrel 1-yr old dogsweighing 18-24 kg were used.The dogswere a crossbreedof labrador, sheepdog, and pointer; both malesand females were used. The animals were fed one mealper day consistingof 500g fresh meat for dogs mixed with vegetables enriched with vitamins. Weight was monitored daily and kept constant over the experimental period. After abdominal surgery, the animalswere nourishedby intravenous infusion of 500 ml of concentrated amino acids, electrolytes, and glucose(AKE 1100,Fresenius). After a 24-h fast, the dogs were anesthetized with 2vG52
0193-1857/92
$2.00
and Toxicology,
3’-dimethylaminopropyl-3-propionylphenothiazine phosphate (Combelen,Bayer), 0.5 ml/kg body weight, intramuscularly, and 2.5 mg 1-6-dimethylamino-4,4-diphenyl-3-3 heptanone hydrochloride, 1 mg methyl-4-hydrobenzoate; (Polamivet, Hoechst) maximum 0.5 ml/kg body weight intravenously. NaCl (0.9%) was infused during the operation. Surgeries were performed under aseptic conditions. A gas-sterilized set of five platinum electrodesand sevenstrain gaugeforce transducersconnectedto a 31-pin plug (ITT Cannon Electric, Santa Ana, CA) with Teflon-coated silver wires (Cicoil, Chatsworth, CA) wasimplanted asdescribedearlier (7). The plug waspositioned subcutaneously between the scapulae.Wires were tunneled to the abdominal wall and from there into the peritoneal cavity where the strain gaugesand the electrodeswere suturedto the seromuscularlayer in the transverse axis of the antrum, pylorus, and duodenum. Three miniature strain gauges(R. Bass,Madison, WI) and one electrodewere placed at the pylorus. A 3.5 Fr Groshong silicon catheter (Catheter Technology, Salt Lake City, UT) was installed via the arteria gastroomentalisdextra into the retropyloric arterial supply, and the port wasimplanted subcutaneously in the thoracic region. The following drugswere used.Hexane-1,6-bis[trimethylammonium chloride] (hexamethonium chloride, C&H3&12N2; Sigma, St. Louis, MO) (25 mg/2 ml 5% glucose)was administered via the arterial port system; atropine sulfate (Braun, Melsungen,FRG) (1 mg/l ml H,O) wasadministered via the arterial port system. H,O-soluble erythromycin lactobionate (Abbott, Wiesbaden, FRG) (300 mg/200 ml 0.9% NaCl) was administeredintravenously over 2 h; neostigminemethylsulfate (Prostigmin, Hoffmann-La Roche, Nutley, NJ) (0.5 mg/l ml) wasadministeredintravenously as 2 ml/200 ml 0.9% NaCl over 1 h. Hexamethonium (25 mg) was administered intra-arterially during the interdigestive state 15min beforethe expectedend of phaseII of the migrating myoelectric complex (MMC) and in the digestive state 15 min after food intake. The experimental seriesincluded 17 animals for the interdigestive and the digestive experiments. Hexamethonium was alsoapplied 20-30 min after the beginning of intravenous erythromycin infusion. This seriesincluded nine animals. Atropine (1 mg) was applied intra-arterially with the same time course as hexamethonium. The seriesincluded nine animalsin the digestive state. Atropine wasalsoapplied 20-30 min after intravenous erythromycin infusion was begun. Apart from these experiments, erythromycin or Prostigmin was given intravenously in the first few days after operation. These experiments included 15 animals that received erythromycin alone and 14 animals that received Prostigmin alone. During all the pharmacological experiments, gastrointestinal motility was recordedover at least a 10-h period. Protocols. All 17 animalswere usedin the erythromycin experiments, and 15 of them were used in the Prostigmin experiments.In nine animalsof the first group, hexamethonium was administered intra-arterially in addition. In a further experiment, intra-arterial atropine was administered at different times in nine animals during erythromycin infusion.
Copyright 0 1992 the American Physiological
Soci’ety
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR
EFFECTS
/.
1000’
G53
OF ERYTHROMYCIN
T\ -r
ii ‘0 ,r 800
l V 0
3.;- 600 ii
Antrum Pylorua Duodenum
400
-\+ 1 I
=v
200
nl NaCl
w I
I
Y-w= A
Am
-
0
-60
60
0
120
180 Time
B el
1”
0
300
420
360
min.
Erythromycin i I I
I I
. . . . . .
240
-
. . . . . . . . . . . . .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . .
..J........
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..b
1”
30
1
60
”
1
90
”
. . . . . . . . . . . . . . . . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . ..
1
120
’
11
16
150 time
1
180
”
I”
210
11
240
’
I
270
’
11
11
300
1
330
min.
Fig. 1. A: motility index (MI) calculated from strain gauges in antrum, pylorus, and duodenum before, during (120 min), and after 10 mg/kg of body weight erythromycin infused intravenously over 120 min in 9 dogs. B: motility registration over 330 min in 1 dog before, during, and after 300 mg erythromycin intravenous infusion over 110 min from electrode in distal antrum (el) and from strain gauge force transducers in distal antrum (a2), prepylorically (p6), pylorus minor curvature side (p5), and pars descendens duodeni (d4). Vertical dashed lines, beginning and end of erythromycin administered intravenously.
All motility measurementswere performed in the unanesthetized animal after a 24-h fast over a period of at least 10 h. In experiments done during the interdigestive state, a full cycle of the MMC was registered at the onset. If no MMC was seen, which was mostly the casein the early postoperative state, at
least 150 min of recording elapsedbefore erythromycin or Prostigmin infusion was started. In the digestive state, a meal of 280 g meat wasgiven after a full MMC cycle or after at least 150 min of interdigestive motility had beenrecorded.In the interdigestive experimentswith
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
G54
MOTOR
EFFECTS
OF ERYTHROMYCIN
the highest physiological contraction by at least 25%. MI was calculated for each phaseand condition, and mean values were expressedper hour. In the digestive state, MI was calculated for each 15-30 min and then averagedin stepsof 1 h over the whole period. Slow waveswere calibrated by the Hellige AC amplifier, and amplitude was given in microvolts and millivolts. Frequency was calculated by visual inspection. The number of contractions was related to the number of slowwavesin the given time period and expressedascontractile activity percentage.Paired Student’s t test wasusedfor statistical analyses (P < 0.05 indicated significant difference), and data are expressedas meanst SD.
1000 900 800 0
Duodenum
700 ii 600 ‘D -c h 500 .-w -.; 400 I 300 200
RESULTS
100 0 -60
0
60
120
180 Time
240
300
360
420
(min)
Fig. 2. MI calculated from strain gauges in antrum, pylorus, and duodenum before, during (120 min), and after 0.5 mg neostigmine intravenous infusion in 5 dogs.
6F
Hexamethonium
P 1
I
1
phase
I
t MMC
t t Erythromycin -I
post
drugs
2h
m 1
0
t b
’
I
II
III
IV
Fig. 3. Slow-wave frequency in gastric antrum of 9 dogs. I, interdigestive state; II, after intravenous erythromycin infusion (300 mg/200 ml 9% NaCl over 2 h); III, after hexamethonium (25 mg) intra-arterially to the pylorus, during erythromycin infusion (20-30 min after beginning); IV, 15 min after stopping erythromycin infusion.
hexamethonium alone or atropine alone, the drug was applied intra-arterially either 15 min before the expectedend of phaseII of the MMC or 15 min after food in the digestive state. When hexamethonium or atropine was administered during erythromycin or Prostigmin infusion, administration occurred 36 min after erythromycin was started. Controls consistedof either the solvent for the drugs or 0.9% NaCl administered in identical volumes as the drug-containing solutions. The strain gaugeswere connectedto Wheatstone half-bridges (Vishay Micro-Measurements) and the electrodesto Hellige AC amplifying system(time constant 7 = 0.1-0.3 s). All signalswere recorded on an eight-channel rectilinear recorder. Recording was continued for at least 10 h. Data obtained from the force transducersand from the electrodes were analyzed as follows: amplitude of contractions was graded as 1, 2, 3, 4, or 4*, and the motility index (MI) was calculated from the formula MI = (x, X 1) + (x, X 2) + (x, X 4) + (x4 x 8), where x representsthe number of contractions and 1, 2, 4, and 8, their force range. Grade 4 contractions occur mainly during phaseIII of the MMC. The force rangefor grade 1 was -5-10 g; for grade 2, -10-20 g; for grade 3, -20-40 g; and for grade 4, ~40-80 g (10). Grade 4” contractions exceed
Erythromycin or Prostigmin administration. In the first few days after surgery, motility was diminished in the stomach and duodenum. In phase II of the MMC, MI was 63 t 38 in the gastric antrum, 94 t 34 in the pylorus, and 151 t 155 in the duodenum. Intravenous infusion of 300 mg erythromycin over 2 h resulted in a sudden MI increase to 1,096 t 286 in the antrum, 1,446 t 237 in the pylorus, and 1,260 t 410 in the duodenum. This represented a 17-fold increase in the motility of the antrum, a 15-fold increase in the pylorus, and an &fold increase in the duodenum (Fig. 1). Whereas erythromycin took effect very rapidly, within a few minutes after commencement of the infusion, the reaction to Prostigmin was slower, reaching the full effect, which was 20% less than that of erythromycin, after 20-30 min (Fig. 2). The motor activity produced by erythromycin ceased promptly after infusion stopped, whereas the effect of Prostigmin was still visible over the next 100 min. Erythromycin administration resulted in bradyarrhythmia of a 30% reduction in the frequency of the basic electrical slow waves in the gastric antrum and pylorus (P < 0.001). It decreased the slow-wave frequency from 4.9 t 0.6 to 3.5 t O.O5/min (Fig. 3). In 88% of the experiments with erythromycin, retrograde giant contractions occurred in the duodenum. These were accompanied by retching and to a lesser degree by vomiting. Hexamethonium or atropine alone. Intra-arterial administration of 25 mg hexamethonium close to the pylorus at the end of phase II of the second registered MMC promptly abolished the contractile activity for 8.5 t 5 min. When the blockade finished, motility continued undiminished until the end of the experiment. The MMCcycle in which the hexamethonium was administered was nonsignificantly longer (149 t 60 min) than the one before (124 t 31 min) and the three after, which were irregular in time (104 t 50,120 t 39, and 180 t 104 min). Hexamethonium in the digestive state abolished contractile activity for 11.8 t 7.2 min (Figs. 4 and 5). MI was reduced for 15 min when contractions began to recur and were followed by normal, powerful contractions (Fig. 5). Administration of the solvent alone or of 2 ml 0.9% NaCl intra-arterially had no effect on motility (Fig. 6). When atropine was given 15 min after food, motility in the antrum, pylorus, and duodenum ceased for 44 t 5.8 min and the MI was extremely low in the subsequent 30 min, decreasing from 306 t 134 before atropine to 41 t 25 after the drug in the antrum, from 361 t 249 to 49 t 45
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR
G55
OF ERYTHROMYCIN
hexa methonium 25 mg LA.
F
All
EFFECTS
+
D IV
E3
1
I
---
Fig. 4. Recordings from the digestive state of one dog (15 min after a 280-g meat meal). Hexamethonium (25 mg) in 2 ml 5% glucose close intra-arterially to pylorus. Mechanical activity in antrum (AII), pylorus (PVI, PV, and PVII), and pars descendens duodeni (DIV). Electrical activity in antrum (E2), pylorus (E3), and pars descendens duodeni (E5). Vertical bars at the strain gauges, contraction grade 4 = 80 g; at the electrodes, 350 pV. Contraction activity ceased following hexamethonium for 11.2 min. Short attack of tachygastria can be seen from the electrodes during motility cessation.
---
T ....
hexamethonium 25 mg
TT
antrum pyloric duodenum
*
0
11 Amin
30min
MOmin
>200min
9.2
Fig. 5. MI calculated from strain gauge recordings in antrum, pylorus, and duodenum in 14 14 dogs in digestive state. Hexamethonium (25 mg) administered close intra-arterially to the pylorus 15 min after a 280-g meat meat meal. Motility ceased completely for 11.8 t 7.2 min following hexamethonium infusion.
in the pylorus, and from 341 t 335 to 68 t 103 in the duodenum, representing decreases of 87, 87, and 80%, respectively. Motility never recovered fully from atropine during the course of the experiment (Fig. 7).
Hexamethonium or atropine after erythromycin. When hexamethonium was applied intra-arterially close to the pylorus 20-30 min after the start of erythromycin inf& sion, motility was abolished for 7.2 t 2.9 min. This effect was similar to the results with hexamethonium without erythromycin. After the abolition, motility values remained at the low levels seen before erythromycin stimulation until the end of the experiment. This suggests that the single dose of 25 mg hexamethonium, after a total block of contractile activity for 7.2 min, permanently abolished the stimulatory effect of erythromycin (Fig. 8). Atropine, when given intra-arterially close to the pylorus during intravenous erythromycin infusion, resulted in complete block of contractile activity in the antrum, pylorus, and duodenum for 51 t 25 min. This was followed by MI values resembling those before erythromycin. That persisted until the end of the experiment (Fig. 9). Hexamethonium or atropine restored the electrical slow waves from the condition of bradyarrhythmia seen during erythromycin administration. Hexamethonium increased the basic electrical rhythmic frequency significantly by 48% (P < 0.001) and atropine by 15-20% (Fig.
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
G56
MOTOR 2ml
EFFECTS
gluoose
OF ERYTHROMYCIN
5% I.A.
P VI
El
1
’
,
I
/
I
I
I
, ’
i
’
I
E3
Fig. 6. Control recordings during the digestive state of 1 dog. Solvent (2 ml 5% glucose) was administered close intra-arterially to pylorus 15 min after a meal. Registration from strain gauges and electrodes were identical to those in Fig. 4. No effects were seen after administration of solvent.
atropine 1.0 mg
A meal ’-1
400
--. . . .
I
x $300 l-l R 2200
antrum pylorus duodenum
blockade persisted only for 2 min, and atropine produced a prompt and long-lasting blockade (30-45 min) only in the duodenum. The total blockade in the antrum and pylorus lasted -5 min after a latency period of 6 min.
’
DISCUSSION
l r( 4 0
%oo
0
442 5.8min
30min
>80min
>2OOmin
Fig. 7. MI calculated from strain gauge recordings in antrum, pylorus, and duodenum in 9 dogs in the digestive state. Fifteen minutes after a 280-g meat meal, 1.0 mg atropine was administered close intra-arterially to pylorus. Motility ceased completely for 44 t 5.8 min.
3). With either drug, short (cl-2 min) attacks of tachygastria occurred with slow-wave frequency of lo-12/min in the antrum and pylorus (Fig. 4). This occurred in >50% of the animals. Some of the dogs seemed to be predisposed to this disturbance. Hexamethonium or atropine after Prostigmin. Hexamethonium or atropine had a much weaker effect after Prostigmin administration than after erythromycin. With the dosages described above, hexamethonium
In the present experiment, the powerful excitatory effects of erythromycin on motility of the upper gastrointestinal tract, which was also seen by others (8, 11, 13), was demonstrated by direct measurement of electrical and contractile behavior when the drug was given intravenously over 2 h. Even during postoperative motility disturbances, the drug produced prompt increases in the contractile frequency percentage to values seen during activity phase III of the MMC combined with vigorous enhancement of the MI. This effect exceeded that of Prostigmin, an acetylcholinesterase-blocking drug (6). The motor activity evoked by erythromycin ceased rapidly after the infusion was stopped. This was also observed in humans (15). This is in contrast to the behavior for Prostigmin, in which the motility only slowed down over the next 100 min. Although the erythromycin-initiated contractions were possibly propagated, the increased motility observed after intravenous administration of 10 mg/kg body w-t erythromycin in our experiment cannot be interpreted as phase
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR
EFFECTS
Erythromycin
300
+
G57
OF ERYTHROMYCIN mL1: I.V.
2 h
hexamethonium 25 mg
1500
-
a
-
. . . . I
T
4
I . . . . . . . . . . . . -I--.jt B .A-- I .Am1.1 .
11
Z2.9min
antrum pylorua duodenum
30min
.
l
MOmin
>200min
Fig. 8. MI calculated from strain gauge recordings in antrum, pylorus, and duodenum in 9 dogs before, during (120 min) and after intravenous erythromycin (300 mg) infusion. Hexamethonium (25 mg) was administered close intra-arterially to pylorus 20 min after erythromycin infusion starts. Motility ceased completely for 7.2 t 2.9 min after hexamethonium. Subsequent motility no longer reflects erythromycin effect, despite that infusion was still running.
III of the MMC. Erythromycin in a dosage of 8 mg/kg did not trigger MMCs in humans (15). But with dosages 200min
aline, and pentagastrin. J. Physiol. Lond. 279: 309-320, 1978. 4. Fox, J. E. T., E. E. Daniel, J. Jury, A. E. Fox, and S. M. Collins. Sites and mechanisms of action of neuropeptides on canine gastric motility differ in vivo and in vitro. Life Sci. 33: 817-825, 1983. 5. Gullikson, G. W., H. Okuda, M. Shimizu, and P. Bass. Electrical arrhythmias in gastric antrum of the dog. Am. J. PhysioL. 239 (Gastrointest.
Liver
Physiol.
2): G59-G68,
1980.
6. Holle, G. E. Small intestinal motility disturbances following abdominal surgery. Langenbecks Arch. Chir. Suppl. (Kongressbericht 1991): 324, 1991. 7. Holle, G. E., K. Milenov, and W. Forth. Adrenergic control of interdigestive and digestive motility via the pyloric region. J. Gastrointest. Motil. 3: 131-137, 1991. 8. Itoh, Z., M. Nakaya, T. Suzuki, H. Arai, and K. Wakabayashi. Erythromycin mimics exogenous motilin in gastrointestinal contractile activity in the dog. Am. J. PhysioZ. 247 (Gastrointest. Liver Physiol. 10): G688-G694, 1984. 9. Kim, C. H., F. Azpiroz, and J. R. Malagelada. Characteristics of spontaneous and drug induced gastric dysrhythmia in a chronic canine model. Gastroenterology 90: 421-427, 1987. 10. Ludwick, J. R., J. N. Wiley, and P. Bass. Extraluminal contractile force and electrical activity of reversed canine duodenum. Gastroenterology 54: 41-51, 1968. 11. Otterson, M. F., and S. K. Sarna. Gastrointestinal motor effects of erythromycin. Am. J. Physiol. 259 (Gastrointest. Liver Physiol. 22): G355-G363, 1990. 12. Peeters, T., G. Matthijs, J. Depoortere, T. Cachet, J. Hoogmartens, and G. Vantrappen. Erythromycin is a motilin receptor agonist. Am. J. Physiol. 257 (Gastrointest. Liver Physiol.
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
MOTOR 20): G470-G474,
EFFECTS
similar
1989.
Pilat, M. A., H. D. Ritchie, H. H. Thompson, and G. P. Zara. Alterations in gastrointestinal motility associated with erythromycin (Abstract). B. J. Phurmacol. 81: 168P, 1984. 14. Sanders, K. M. Role of prostaglandins in regulating gastric motility. Am. J. Physiol. 247 (Gastrointest. Liver Physiol. 10): GlmG126, 1984. 15. Sarna, S. K., K. H. Soergel, T. R. Koch, J. E. Stone, C. M. Wood, R. P. Ryan, J. H. Cavanaugh, H. N. H. Nellans, and M. B. Lee. Effect of erythromycin on human gastrointestinal motor activity in the fasted and fed states (Abstract). Gastroen-
Pharmacol.
13.
terology 16.
96: A440,
1989.
Satoh, T., N. Inatomi, H. Satoh, S. Marni, Z. Itoh, and S. Omura. EM-523, an erythromycin derivative and motilin show
G59
OF ERYTHROMYCIN
17.
contractile Exp.
Ther.
activity
in isolated
254: 940-944,
rabbit
intestine.
J.
1990.
Telander, R. L., K. G. Morgan, D. L. Kreulen, P. F. Schmalz, K. A. Kelly, and J. H. Szurszewski. Human gastric atony with tachygastric and gastric retention. Gastroenterology 75: 497-501,
1978.
Tomomasa, T., T. Kuroume, H. Arai, K. Wakabayashi, and Z. Itoh. Erythromycin induces migrating motor complex in human gastrointestinal tract. Dig. Dis. Sci. 31: 157-161, 1986. 19. Urbain, J. L. C., G. Vantrappen, 3. Janssens, E. Van Cutsem, T. Peeters, and M. DeRoo. Intravenous Erythromycin dramatically accelerates gastric emptying in gastroparesis diabeticorum and normals and abolishes the emptying discrimination between solids and liquids. J. Nuclear Med. 31: 1490-1493, 1990. 18.
Downloaded from www.physiology.org/journal/ajpgi by ${individualUser.givenNames} ${individualUser.surname} (163.015.154.053) on October 24, 2018. Copyright © 1992 American Physiological Society. All rights reserved.
