Acute hypoxia influence on pulmonary and systemic blood circulation

Abstract

We investigate the influence of normobaric hypoxia (of 10, 7,5, 5 and 3% O2 in nitrogen) on pulmonary and systemic blood circulation of anesthetized cats and rats. We ascertain that the hypoxia led to systemic minute blood flow redistribution between different organs in according to their metabolic demands, during insignificant heart output changes. Hypoxia induces an increase of pulmonary arterial pressure and pulmonary vascular resistance during nearly steady lung perfusion. This condition promotes to save a balance between left and right heart ventricular output. The hemodynamic changes were various in different hypoxia-resistant animals in condition of very heavy hypoxia (3% O2).