The Effects of Endogenous and Exogenous Histamine on Pulmonary Alveolar Membrane Permeability!' 2
KATHY PROPST, J. EUGENE MILLEN, and FREDERICK L. GLAUSER
SUMMARY _________________________________________________________ The effects of exogenously administered histamine phosphate (0.1 ,..g per kg of body weight per min, or 90 ,..g per hour) and endogenous histamine released by intravenous injection of 0.5 mg of Compound 48/80 on alveolar membrane permeability to substances of differing molecular weight (60 to 20,000 daltons) were studied using the in vivo saline-filled dog lung model. The half-time, Le., the time required for 50 per cent equilibration between tracer substances in the blood compared to the saline-filled lung, was measured at baseline for urea, sucrose, and dextrans of varying molecular weighL The half-time decreased significantly for substances as large as 10.000 daltons after histamine infusion, and 20,000 daltons after injection of Compound 48/80. We conclude that histamine can increase alveolar epithelial permeability for substances of low molecular weighL
Introduction Increased lung vascular permeability has been implicated as a primary cause of the noncardiogenic pulmonary edema associated with such diverse clinical conditions as septicemia, drug overdose, pancreatitis, and trauma. Recently, Brigham (1) has suggested 3 factors (humoral, cellular, and neural) that either singly or in combination could alter lung vascular permeability_ Of the humoral factors, histamine remains a prime candidate, because infusion of as little as 4 ,..g of histamine phosphate per kg of body weight per min caused a marked increase in lung lymph flow and the ratio of lymph to plasma protein (reflecting the increased vascular permeability) in the unanesthetized sheep with chronically implanted lung lymphatic catheters (2). (Received in original form October J, 1977 and in revised form Febru.ary IJ, 1978) 1 From the Department of Medicine, Long Beach Veterans Administration Hospital, Long Beach, Cal. 2 Requests for reprints should be addressed to Frederick L. Glauser, M_D., Chairman, Pulmonary Division, Medical College of Virginia, Box 93, 1200 E. Broad St., Richmond, Va. 23298.
We have investigated the effects of exogenously infused and endogenously released histamine on the permeability of the alveolar epithelial membrane using the in vivo salinefilled dog lung preparation.
Materials and Methods The in vivo transalveolar movement of urea, sucrose, and dextrans of differing molecular weight (3,000, 10,000 and 20,000 daltons) was measured in saline-filled segments of dog lungs (3) before (baseline) and after continuous intravenous infusion of histamine phosphate (group 1) at a rate of 0.1 ,..g per kg of body weight per min (90,..g per hour) or the injection of 0_5 mg of Compound 48/80 (group 2). Briefly, the technique was as follows. Mongrel dogs weighing 15 ± 2 kg were anesthetized with 30 mg of sodium pentobarbital per kg of body weight; a tracheostomy was performed, and a Carlens catheter was inserted so as to separate the 2 lungs_ This placement was verified at autopsy_ A Harvard pump was attached to both arms of the Carlens catheter, and the dogs were ventilated with 100 per cent 02 at a frequency of 24 to 48 breaths per min and a tidal volume of 16 ml per kg of body weighL The kidneys were exposed and externalized, and the renal pedicles were ligated with heavy sutures. A pulmonary arterial catheter was inserted via a femoral vein under pressure monitoring_ A
AMERICAN REVIEW OF RESPIRATORY DISEASE, VOLUME 117,1978
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femoral arterial catheter was also inserted; this line was used for blood sampling and direct continuous monitoring of blood pressure. Exogenous solutes (0.5 g of FITC fluorescent· labeled dextran in 10 ml of 0.9 per cent NaCI solution and/or 10 g of sucrose in 50 ml of 0.9 per cent NaCI solution) were injected into the pulmonary arterial catheter. Two hours were allowed for achievement of a constant plasma concentration of the indicator. After this 2-hour period, the animal was placed in the 15- to 25-degree head-up position. The left arm of the Carlens catheter was damped and maintained for 10 to 15 min at end-expiration to induce atelectasis, and ventilation was carried out through the right arm with a tidal volume of 8 ml per kg of body weight at 24 to 28 breaths per min. After this, the left arm of the Carlens catheter was undamped, and a no. 5 Swan Ganz catheter (for injection and aspiration) was threaded down the Carlens catheter until it wedged; 200 ml of 0.9 per cent NaCI solution were instilled into the left lung. Airway pressure was atmospheric because the left arm of the Carlens catheter was open to room air, and no ventilation occurred via this arm. Simultaneous blood and "alveolar" liquid samples were obtained for urea, sucrose, dextran, and histamine analyses every 15 min for 60 to 120 min after instillation. Two- to 3-ml aliquots of "alveolar" liquid were withdrawn through the Swan Ganz catheter every 15 min. This volume was not replaced. After this baseline period, dogs were divided into 2 groups. The 20 animals in group I were infused with 0.1 p,g of histamine phosphate per kg of body weight per min. In anyone dog, a maximum of 3 substances (urea, sucrose, and an FITC dextran) could be measured simultaneously. Histamine infusion continued for the entire experiment (average duration, 4.5 hours) after the baseline period, and blood and alveolar liquid samples were obtained every 15 min. In 4 preliminary experiments, the dose of histamine phosphate used was the highest that did not affect baseline cardiac output, blood pressure, pulmonary wedge pressure, pulmonary arterial pressure, arterial P0 2 (Pao2), arterial Pco2 (Paco2),
or pH. In addition, these parameters were measured in all animals during the actual experiment. In any single experiment, if these hemodynamic parameters varied significantly from baseline values, the experiment was discarded. The 20 animals of group 2 were injected intravenously with 0.5 mg of Compound 48/80. Blood and "alveolar" liquid samples were obtained every 15 min for an average of 4.5 hours. The dose of Compound 48/80 used was the highest that did not alter baseline cardiac output, blood pressure, pulmonary arterial pressure, Pao2, Paco2' and pH compared to baseline values in 4 preliminary experiments. Any experiment in which these parameters were significantly altered from baseline was discarded. Specific methodology. Pressure monitoring was performed using a Statham PdB transducer and an Electronics for Medicine VR-6 physiologic recorder. Urea and FITC dextran determinations were performed by the fluorometric technique on a Turner fluorometer (4). Sucrose was determined by the anthrone method (5). Histamine was determined fluorometrically by a modification of the method of Shore and associates (6). In our laboratory, the sensitivity of this method is reflected in the fact that we can detect histamine concentrations as low as I to 1.5 p,g per ml. For statistical analysis we used "Student's" paired t test to compare baseline and experimental data. Calculations. The inherent problems involved in calculating the time for 50 per cent equilibration (tY2) and the apparent permeability (p') in this model are discussed in detail by Theodore and co-workers (3) and Fischer and associates (7). The formulas for calculating tY2 and p', assuming a single compartment of constant volume exchanging with a large volume (plasma) of constant composition are as follows: dQa/dt = Va dCa/dt p'A (Cb - Ca) [I], where Qa = the amount of a given molecular species in alveolar liquid, in moles; Va volume of the compartment, in ml; Ca the concentration of a given molecular species in alveolar liquid, in mole per ml; p' = the permeability constant, in cm per sec; A = surface
=
=
=
TABLE 1 HALF-TlME* VALUES FOR 4 SUBSTANCES DIFFERING IN MOLECULAR WEIGHT FOR BASELlNEt COMPARED TO CONTROL PERIODS Half- Time, min Baseline Urea Dextran 3,000 daltons 10,000 daltons 20,000 daltons
56 ± 12 1,388 ±476 1,732 ± 288 2,755 ±339
Control
P Value
41.2±19
NS
1,145 ± 266 1,871±411 2,999 ±698
NS NS NS
'Time required for 50 per cent equilibration of the tracer substance. tPooled data from both histamine phosphate and Compound 48/80 experiments.
1065
HISTAMINE AND ALVEOLAR MEMBRANE PERMEABILITY
TABLE 2 HALF-TIME· VALUES FOR 4 SUBSTANCES DIFFERING IN MOLECULAR WEIGHT Half-time, min No. of Dogs Urea Dextran 3,000 daltons 10,000 daltons 20,000 daltons
Histamine Pho5phate Infusion
Baseline
20
53 ± 15
7 7 6
28 ± 11
1,483 ±450 1,572 ± 170 2,503 ± 186
22B ± 176 693 ±395 2,800 ±720
P Value
KATHY PROPST, J. EUGENE MILLEN, and FREDERICK L. GLAUSER
SUMMARY _________________________________________________________ The effects of exogenously administered histamine phosphate (0.1 ,..g per kg of body weight per min, or 90 ,..g per hour) and endogenous histamine released by intravenous injection of 0.5 mg of Compound 48/80 on alveolar membrane permeability to substances of differing molecular weight (60 to 20,000 daltons) were studied using the in vivo saline-filled dog lung model. The half-time, Le., the time required for 50 per cent equilibration between tracer substances in the blood compared to the saline-filled lung, was measured at baseline for urea, sucrose, and dextrans of varying molecular weighL The half-time decreased significantly for substances as large as 10.000 daltons after histamine infusion, and 20,000 daltons after injection of Compound 48/80. We conclude that histamine can increase alveolar epithelial permeability for substances of low molecular weighL
Introduction Increased lung vascular permeability has been implicated as a primary cause of the noncardiogenic pulmonary edema associated with such diverse clinical conditions as septicemia, drug overdose, pancreatitis, and trauma. Recently, Brigham (1) has suggested 3 factors (humoral, cellular, and neural) that either singly or in combination could alter lung vascular permeability_ Of the humoral factors, histamine remains a prime candidate, because infusion of as little as 4 ,..g of histamine phosphate per kg of body weight per min caused a marked increase in lung lymph flow and the ratio of lymph to plasma protein (reflecting the increased vascular permeability) in the unanesthetized sheep with chronically implanted lung lymphatic catheters (2). (Received in original form October J, 1977 and in revised form Febru.ary IJ, 1978) 1 From the Department of Medicine, Long Beach Veterans Administration Hospital, Long Beach, Cal. 2 Requests for reprints should be addressed to Frederick L. Glauser, M_D., Chairman, Pulmonary Division, Medical College of Virginia, Box 93, 1200 E. Broad St., Richmond, Va. 23298.
We have investigated the effects of exogenously infused and endogenously released histamine on the permeability of the alveolar epithelial membrane using the in vivo salinefilled dog lung preparation.
Materials and Methods The in vivo transalveolar movement of urea, sucrose, and dextrans of differing molecular weight (3,000, 10,000 and 20,000 daltons) was measured in saline-filled segments of dog lungs (3) before (baseline) and after continuous intravenous infusion of histamine phosphate (group 1) at a rate of 0.1 ,..g per kg of body weight per min (90,..g per hour) or the injection of 0_5 mg of Compound 48/80 (group 2). Briefly, the technique was as follows. Mongrel dogs weighing 15 ± 2 kg were anesthetized with 30 mg of sodium pentobarbital per kg of body weight; a tracheostomy was performed, and a Carlens catheter was inserted so as to separate the 2 lungs_ This placement was verified at autopsy_ A Harvard pump was attached to both arms of the Carlens catheter, and the dogs were ventilated with 100 per cent 02 at a frequency of 24 to 48 breaths per min and a tidal volume of 16 ml per kg of body weighL The kidneys were exposed and externalized, and the renal pedicles were ligated with heavy sutures. A pulmonary arterial catheter was inserted via a femoral vein under pressure monitoring_ A
AMERICAN REVIEW OF RESPIRATORY DISEASE, VOLUME 117,1978
1063
1064
PROPST, MILLEN, AND GLAUSER
femoral arterial catheter was also inserted; this line was used for blood sampling and direct continuous monitoring of blood pressure. Exogenous solutes (0.5 g of FITC fluorescent· labeled dextran in 10 ml of 0.9 per cent NaCI solution and/or 10 g of sucrose in 50 ml of 0.9 per cent NaCI solution) were injected into the pulmonary arterial catheter. Two hours were allowed for achievement of a constant plasma concentration of the indicator. After this 2-hour period, the animal was placed in the 15- to 25-degree head-up position. The left arm of the Carlens catheter was damped and maintained for 10 to 15 min at end-expiration to induce atelectasis, and ventilation was carried out through the right arm with a tidal volume of 8 ml per kg of body weight at 24 to 28 breaths per min. After this, the left arm of the Carlens catheter was undamped, and a no. 5 Swan Ganz catheter (for injection and aspiration) was threaded down the Carlens catheter until it wedged; 200 ml of 0.9 per cent NaCI solution were instilled into the left lung. Airway pressure was atmospheric because the left arm of the Carlens catheter was open to room air, and no ventilation occurred via this arm. Simultaneous blood and "alveolar" liquid samples were obtained for urea, sucrose, dextran, and histamine analyses every 15 min for 60 to 120 min after instillation. Two- to 3-ml aliquots of "alveolar" liquid were withdrawn through the Swan Ganz catheter every 15 min. This volume was not replaced. After this baseline period, dogs were divided into 2 groups. The 20 animals in group I were infused with 0.1 p,g of histamine phosphate per kg of body weight per min. In anyone dog, a maximum of 3 substances (urea, sucrose, and an FITC dextran) could be measured simultaneously. Histamine infusion continued for the entire experiment (average duration, 4.5 hours) after the baseline period, and blood and alveolar liquid samples were obtained every 15 min. In 4 preliminary experiments, the dose of histamine phosphate used was the highest that did not affect baseline cardiac output, blood pressure, pulmonary wedge pressure, pulmonary arterial pressure, arterial P0 2 (Pao2), arterial Pco2 (Paco2),
or pH. In addition, these parameters were measured in all animals during the actual experiment. In any single experiment, if these hemodynamic parameters varied significantly from baseline values, the experiment was discarded. The 20 animals of group 2 were injected intravenously with 0.5 mg of Compound 48/80. Blood and "alveolar" liquid samples were obtained every 15 min for an average of 4.5 hours. The dose of Compound 48/80 used was the highest that did not alter baseline cardiac output, blood pressure, pulmonary arterial pressure, Pao2, Paco2' and pH compared to baseline values in 4 preliminary experiments. Any experiment in which these parameters were significantly altered from baseline was discarded. Specific methodology. Pressure monitoring was performed using a Statham PdB transducer and an Electronics for Medicine VR-6 physiologic recorder. Urea and FITC dextran determinations were performed by the fluorometric technique on a Turner fluorometer (4). Sucrose was determined by the anthrone method (5). Histamine was determined fluorometrically by a modification of the method of Shore and associates (6). In our laboratory, the sensitivity of this method is reflected in the fact that we can detect histamine concentrations as low as I to 1.5 p,g per ml. For statistical analysis we used "Student's" paired t test to compare baseline and experimental data. Calculations. The inherent problems involved in calculating the time for 50 per cent equilibration (tY2) and the apparent permeability (p') in this model are discussed in detail by Theodore and co-workers (3) and Fischer and associates (7). The formulas for calculating tY2 and p', assuming a single compartment of constant volume exchanging with a large volume (plasma) of constant composition are as follows: dQa/dt = Va dCa/dt p'A (Cb - Ca) [I], where Qa = the amount of a given molecular species in alveolar liquid, in moles; Va volume of the compartment, in ml; Ca the concentration of a given molecular species in alveolar liquid, in mole per ml; p' = the permeability constant, in cm per sec; A = surface
=
=
=
TABLE 1 HALF-TlME* VALUES FOR 4 SUBSTANCES DIFFERING IN MOLECULAR WEIGHT FOR BASELlNEt COMPARED TO CONTROL PERIODS Half- Time, min Baseline Urea Dextran 3,000 daltons 10,000 daltons 20,000 daltons
56 ± 12 1,388 ±476 1,732 ± 288 2,755 ±339
Control
P Value
41.2±19
NS
1,145 ± 266 1,871±411 2,999 ±698
NS NS NS
'Time required for 50 per cent equilibration of the tracer substance. tPooled data from both histamine phosphate and Compound 48/80 experiments.
1065
HISTAMINE AND ALVEOLAR MEMBRANE PERMEABILITY
TABLE 2 HALF-TIME· VALUES FOR 4 SUBSTANCES DIFFERING IN MOLECULAR WEIGHT Half-time, min No. of Dogs Urea Dextran 3,000 daltons 10,000 daltons 20,000 daltons
Histamine Pho5phate Infusion
Baseline
20
53 ± 15
7 7 6
28 ± 11
1,483 ±450 1,572 ± 170 2,503 ± 186
22B ± 176 693 ±395 2,800 ±720
P Value
