The perfused guinea-pig lung revisited: a study of EDRF-no system.
Adult male guinea pigs from both sexes were anaesthetized with pentobarbital (40mg/Kg). After tracheotomy the lungs were perfused with Krebs-Henseleit solution at 37 degrees C in a non recirculated system composed of a perfusion pump, a transducer to measure pressure and another one to measure bronchial resistance. In all groups studied histamine injections were made at the doses of 50, 100, 200 and 400 microg/ml as a bolus. Propranolol (1 microg/ml) added to the perfusate, promoted a remarkable increase in perfusion pressure (p<0.001) and a significant augmentation in bronchoconstriction (p<0.05). When indometacin (10 microg/ml) was added to the perfusate, a great increase in histamine induced bronchoconstriction was observed, that was followed by a remarkable increase in perfusion pressure. Methylene blue at the dose of 8.25 microg/ml increased bronchorreativity as well as the perfusion pressure significantly. L-arginine (3.5 microg/ml) added to the perfusate, did not promote reactivity. The addition of L-arginine plus NADPH (1 microg/ml), promoted a significant decrease in bronchoconstriction (p<0.01). In both cases, perfusion pressure increased when compared to controls. Nitroarginine (2.5 microg/ml) greatly increased perfusion pressure with no change in bronchoconstriction. Therefore, we conclude that nitric oxide (NO) is a very important modulator for keeping the low perfusion pressure and bronchodilation of the isolated perfused guinea pig lung.
Fonteles
C S
CS
Departamento de Fisiologia e Farmacologia, Unidade de Pesquisas Clinicas Centro de Ciencias da Saude, Fortaleza-Ce, Brazil.
Fonteles
M C
MC
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000403:Airway Resistance / Q000502:physiology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001794:Blood Pressure; D001980:Bronchi / Q000502:physiology; D016084:Bronchoconstriction / Q000502:physiology; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008168:Lung / Q000502:physiology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D009249:NADP / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*; D010477:Perfusion; D011433:Propranolol / Q000494:pharmacology
D000319:Adrenergic beta-Antagonists; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009569:Nitric Oxide; D009249:NADP; D011433:Propranolol; D007213:Indomethacin