Effect of dopamine on platelet activating factor induced-pulmonary edema in isolated and perfused rabbit lungs.
The effect of dopamine over pulmonary edema induced by PAF was studied. Thirty preparations of rabbit lungs were used: six control preparations (CP), six PAF preparations (PP) in which we injected a dose of 1 microg/kg of rabbit weight and eighteen dopamine preparations (DAP) divided in three groups of six pretreated with a dose of 1-5 (dopaminergic range), 10-20 (Beta range) and 20-30 ug/kg/min (Alpha range) of dopamine, respectively for 30 min, followed by an injection of PAF as in the PP. DAP at Beta and Alpha-adrenergic range decreased pulmonary artery pressure (Pap) as compared to CP, with values of 11.66 (CI 95%: 10.83-12.48), 11.66 (CI 95%: 9.87-13.44) versus 17.12 (CI 95%: 16.12-18.11) cm of water, respectively. DAP in Beta and Alpha-adrenergic range prevented Pap increment as compared to PP, with values of 17.16 (CI 95%: 16.37-17.94), 17.5 (CI 95%: 14.93-20.06) versus 84 cm of water (CI 95%: 71.41-96.58), respectively. Dopamine, at its three ranges inhibited the augmentation of the fluid filtration rate observed in PP with values of 1.01 (CI 95%: 0.77-1.24), 0.03 (CI 95%: 0.01-0.04) and 0.02 g/min (CI 95%: -0.0004-0.03) versus 2.13 g/min (CI 95%: 1.56-2.69), respectively. We concluded that dopamine has a vasodilator effect on Pap and exerts an inhibiting action over PAF effects in pulmonary circulation. Such effects seem to be mainly mediated by Beta-receptors, rather than by dopaminergic receptors.
Marcano
H
H
Section of Respiratory Physiology, Institute of Experimental Medicine, Faculty of Medicine, Luis Razetti School of Medicine, Central University of Venezuela, Caracas, Venezuela. rsanchez@ven.net
Novoa
E
E
Friedman
E
E
Crespo
A
A
Tortoledo
M
M
Sánchez de León
R
R
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004298:Dopamine / Q000008:administration & dosage / Q000494:pharmacology*; D066298:In Vitro Techniques; D018836:Inflammation Mediators / Q000494:pharmacology; D010477:Perfusion; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000187:drug effects / Q000503:physiopathology; D011652:Pulmonary Circulation / Q000187:drug effects; D011654:Pulmonary Edema / Q000139:chemically induced* / Q000503:physiopathology; D011817:Rabbits; D018343:Receptors, Adrenergic, beta-2 / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects
D018836:Inflammation Mediators; D010972:Platelet Activating Factor; D018343:Receptors, Adrenergic, beta-2; D004298:Dopamine