Comparison of the effects of minoxidil and nifedipine on hypoxic pulmonary vasoconstriction in dogs.

摘要: We studied the effects of hypoxia on pulmonary hemodynamics and gas exchange before after minoxidil or nifedipine administration. The studies were carried out in eight normal dogs to determine relative these two drugs inhibiting hypoxic vasoconstriction. Each dog was twice--once with each drug--and exposed repeatedly day. Minoxidil raised cardiac output from 2.84 +/- 0.19 4.67 0.29 L/min (mean SE), whereas it 3.04 0.25 4.38 0.38 L/min. Prior drugs, vascular resistance 2.4-fold. abolished this pressor response, while reduced response a 1.6-fold increase. venous admixture during normoxia 6 1 16 4%, 7 11 2%. Both are inhibitors vasoconstrictive hypoxia. At doses used, more potent inhibitor than nifedipine.