Lactate and Pyruvate in the Brain of Rats During Hyperventilation

Abstract

Experiments on anesthetized and curarized rats under artificial ventilation show that during hyperventilation lactate and pyruvate are markedly increased both in blood and in brain. The lactate/pyruvate ratio which remains in blood the same as in control conditions, is systematically decreased in brain. During hypoxia (ventilation with 7 % oxygen in nitrogen) lactate rises markedly in blood and in brain. The lactate/pyruvate ratio which is strongly increased in blood shows a small rise in brain. These observations could indicate that a different mechanism is responsible for the rise of lactate in brain during hypoxia and hyperventilation. The important augmentation of lactate in brain during hyperventilation can give an explanation for the delayed rise which is seen in the lactate level in cerebrospinal fluid in these conditions.