Hemodynamic effects of nifedipine in normoxic and hypoxic newborn lambs.
We studied the effects of nifedipine, a calcium-channel blocker, in two acutely instrumented groups of newborn lambs during normoxic and hypoxic conditions. Nifedipine at 10 or more micrograms/kg reduced systemic, but not pulmonary artery pressure and resistance in normoxic lambs. When acute hypoxia was produced in these animals, 50 or more micrograms/kg reduced, but did not prevent, the expected rise in pulmonary pressure and resistance. When infused into already hypoxic lambs, nifedipine in doses of 50 micrograms/kg or more reduced both systemic and pulmonary pressures and resistances equally. Thus, nifedipine is a nonspecific vasodilator in newborn lambs.
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000187:drug effects*; D006976:Hypertension, Pulmonary / Q000188:drug therapy; D000860:Hypoxia / Q000188:drug therapy / Q000662:veterinary*; D007263:Infusions, Parenteral; D009543:Nifedipine / Q000494:pharmacology* / Q000627:therapeutic use; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D012756:Sheep; D012757:Sheep Diseases
D009543:Nifedipine