Digestion 12: 111-113 (1975)
Transport Studies in the Small Bowel Obstruction of the Rat P. Merkte, D. Breitig and H. Bindewald Abteilung für Allgemeine Chirurgie und Sektion Isotopenanwendung des Zentrums für Klinische Grundlagenforschung der Universität Ulm, Ulm
Key Words. Antipyrine ■Glucose • Intestinal absorption • Intestine obstruction Abstract. In the mechanically obstructed small bowel of the rat the decrease of passive transport of antipyrine was found to be equal after 24 and 48 h. The active transport of glucose was found to be progressively inhibited after occlusion.
The decrease of the transport capacity after occlusion of the small bowel has been investigated in the dog (2, 5) and in the rat (1). Intestinal function has been determined by measuring the absorption during incubation of intestinal rings and was found to be reduced in obstruction (3). The reason is thought to be tissue hypoxia. By studying simultaneously active and passive transport (diffusion) in vivo we have tried to clarify which factors may be responsible for the reduced transport capacity in obstruction.
Materials and Methods In male SPF rats (weight 200 ± 20 g) the small intestine was mechanically obstructed 25 cm below the ligament of Treitz in ether anesthesia. 24 and 48 h later the obstructed bowel was emptied over a length of 20 cm and the content was measured. It was replaced by an identical amount (2 + 0.2 ml) of Ringer’s solution containing 1 nC\ ' 4C-glucose and 2 nC\ 3H-antipyrine. After 15 min this solution was removed, and the bowel was rinsed by addi tional 2 ml of Ringer’s solution. The size of the different groups was between 9 and 13 animals. The remaining radioactivity was determined using a liquid scintillation counter (Packard). The absorption rates corresponded to the total given activity minus the measured rest-activity. Control rats were sham-operated (laparotomy), a bowel piece of the same length was filled with 2 ml of the above-described labelled solution which was also removed after 15 min.
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Received: February 27, 1975: accepted: March 7, 1975.
Merkle/Breitig/Bindewahi
112
Results As shown in the table and figure the absorption of 3 H-antipyrine after 24 h is significantly reduced in the obstructed bowel compared to controls, it is only slightly further reduced after 48 h. The absorption of 14C-glucose after 24 h is similarly reduced, but is, however, distinctly further decreased after 48 h.
Table t. Effect of obstruction on absorption of '"C-glucose and 3H-antipyrine (mean absorption in % ± SE); results were evaluated by Student’s t test Time after obstruction
14C-glucose
control obstruction
3H-antipyrine
control obstruction
24 h
48 h
70.8 t 2.3 57.5 t 8.0 p < 0.0005 57.7 ± 3.0 35.1 ± 10.1 p < 0.0005
67.8 t 4.5 35.0 i 13.8 p < 0.0005 62.2 t 6.4 32.5 ± 7.6 p < 0.0005
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Fig. 1. Effect of obstruction on absorption of u C-glucose and 3H-antipyrinc. The active transport (14C-glucose) is reduced after 24 h and further decreased after 48 h; passive transport (3H-antipyrine) is equally decreased after 24 and 48 h.
Transport Studies in the Small Bowel Obstruction of the Rat
113
Discussion The energy-dependent absorption of glucose is altered in occlusion and decreases corresponding to the duration of obstruction. These findings agree with the in vitro studies o f Kubrova et al. (3). The diffusion of antipyrine (4) is already reduced after 24 h staying, however, essentially constant thereafter. Therefore, we may conclude that up to 24 h after occlusion disturbance of mucosa] permeability is the main cause for the reduced absorption capacity; this disturbance most probably is a consequence of bowel edema, which can be seen histologically in this phase. The further decrease of absorption capacity 48 h after occlusion concerns mostly the active transport and must be caused ‘metabolically’: obviously a tissue hypoxia must be present at this stage. This hypoth esis is supported by the fact that in other studies no alteration of capillary circulation could be observed in obstruction. The lactate-pyruvate ratio in the tissue of the obstructed bowel was three times as high as in the controls (publica tion in preparation).
References
2 3 4 5
Derblom, //.; Johansson, //., and Nytander, G Vascular pattern of intestinal villi in the obstructed small bowel of the rat. Surgery 54: 780-783 (1963). Grace, R.H.: The handling of water and electrolytes by the small bowel following the relief of intestinal obstruction. Br. J. Surg. 58: 760-764 (1971). Kubrova, J„ Robinson, J.W.L. et Mirkovitch, V.: La fonction de la muqueuse après une occlusion aiguë de l’intestin grêle du rat. Res. exp. Med. 160: 321-325 (1973). Schanker, L.S.; Tocco, D.J.; Brodie, B.B., and Hogben, C.A.M.: Absorption of drugs from the rat small intestine. J. pharmac. exp. Ther. 123: 81-88 (1958). Shields, R.: The absorption and secretion of fluid and electrolytes by the obstructed bowel. Br. J. Surg. 52: 774-779 (1965).
Dr. P. Merkte, Departement für Chirurgie, Universität Ulm, D -7 9 Ulm (FRG)
Downloaded by: King's College London 137.73.144.138 - 3/5/2018 11:17:44 PM
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Transport Studies in the Small Bowel Obstruction of the Rat P. Merkte, D. Breitig and H. Bindewald Abteilung für Allgemeine Chirurgie und Sektion Isotopenanwendung des Zentrums für Klinische Grundlagenforschung der Universität Ulm, Ulm
Key Words. Antipyrine ■Glucose • Intestinal absorption • Intestine obstruction Abstract. In the mechanically obstructed small bowel of the rat the decrease of passive transport of antipyrine was found to be equal after 24 and 48 h. The active transport of glucose was found to be progressively inhibited after occlusion.
The decrease of the transport capacity after occlusion of the small bowel has been investigated in the dog (2, 5) and in the rat (1). Intestinal function has been determined by measuring the absorption during incubation of intestinal rings and was found to be reduced in obstruction (3). The reason is thought to be tissue hypoxia. By studying simultaneously active and passive transport (diffusion) in vivo we have tried to clarify which factors may be responsible for the reduced transport capacity in obstruction.
Materials and Methods In male SPF rats (weight 200 ± 20 g) the small intestine was mechanically obstructed 25 cm below the ligament of Treitz in ether anesthesia. 24 and 48 h later the obstructed bowel was emptied over a length of 20 cm and the content was measured. It was replaced by an identical amount (2 + 0.2 ml) of Ringer’s solution containing 1 nC\ ' 4C-glucose and 2 nC\ 3H-antipyrine. After 15 min this solution was removed, and the bowel was rinsed by addi tional 2 ml of Ringer’s solution. The size of the different groups was between 9 and 13 animals. The remaining radioactivity was determined using a liquid scintillation counter (Packard). The absorption rates corresponded to the total given activity minus the measured rest-activity. Control rats were sham-operated (laparotomy), a bowel piece of the same length was filled with 2 ml of the above-described labelled solution which was also removed after 15 min.
Downloaded by: King's College London 137.73.144.138 - 3/5/2018 11:17:44 PM
Received: February 27, 1975: accepted: March 7, 1975.
Merkle/Breitig/Bindewahi
112
Results As shown in the table and figure the absorption of 3 H-antipyrine after 24 h is significantly reduced in the obstructed bowel compared to controls, it is only slightly further reduced after 48 h. The absorption of 14C-glucose after 24 h is similarly reduced, but is, however, distinctly further decreased after 48 h.
Table t. Effect of obstruction on absorption of '"C-glucose and 3H-antipyrine (mean absorption in % ± SE); results were evaluated by Student’s t test Time after obstruction
14C-glucose
control obstruction
3H-antipyrine
control obstruction
24 h
48 h
70.8 t 2.3 57.5 t 8.0 p < 0.0005 57.7 ± 3.0 35.1 ± 10.1 p < 0.0005
67.8 t 4.5 35.0 i 13.8 p < 0.0005 62.2 t 6.4 32.5 ± 7.6 p < 0.0005
Downloaded by: King's College London 137.73.144.138 - 3/5/2018 11:17:44 PM
Fig. 1. Effect of obstruction on absorption of u C-glucose and 3H-antipyrinc. The active transport (14C-glucose) is reduced after 24 h and further decreased after 48 h; passive transport (3H-antipyrine) is equally decreased after 24 and 48 h.
Transport Studies in the Small Bowel Obstruction of the Rat
113
Discussion The energy-dependent absorption of glucose is altered in occlusion and decreases corresponding to the duration of obstruction. These findings agree with the in vitro studies o f Kubrova et al. (3). The diffusion of antipyrine (4) is already reduced after 24 h staying, however, essentially constant thereafter. Therefore, we may conclude that up to 24 h after occlusion disturbance of mucosa] permeability is the main cause for the reduced absorption capacity; this disturbance most probably is a consequence of bowel edema, which can be seen histologically in this phase. The further decrease of absorption capacity 48 h after occlusion concerns mostly the active transport and must be caused ‘metabolically’: obviously a tissue hypoxia must be present at this stage. This hypoth esis is supported by the fact that in other studies no alteration of capillary circulation could be observed in obstruction. The lactate-pyruvate ratio in the tissue of the obstructed bowel was three times as high as in the controls (publica tion in preparation).
References
2 3 4 5
Derblom, //.; Johansson, //., and Nytander, G Vascular pattern of intestinal villi in the obstructed small bowel of the rat. Surgery 54: 780-783 (1963). Grace, R.H.: The handling of water and electrolytes by the small bowel following the relief of intestinal obstruction. Br. J. Surg. 58: 760-764 (1971). Kubrova, J„ Robinson, J.W.L. et Mirkovitch, V.: La fonction de la muqueuse après une occlusion aiguë de l’intestin grêle du rat. Res. exp. Med. 160: 321-325 (1973). Schanker, L.S.; Tocco, D.J.; Brodie, B.B., and Hogben, C.A.M.: Absorption of drugs from the rat small intestine. J. pharmac. exp. Ther. 123: 81-88 (1958). Shields, R.: The absorption and secretion of fluid and electrolytes by the obstructed bowel. Br. J. Surg. 52: 774-779 (1965).
Dr. P. Merkte, Departement für Chirurgie, Universität Ulm, D -7 9 Ulm (FRG)
Downloaded by: King's College London 137.73.144.138 - 3/5/2018 11:17:44 PM
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