Lactate and pyruvate gradients between red blood cells and plasma during acute asphyxia

Abstract

The rate of equilibration of lactate and pyruvate between plasma and red cells has been studied during asphyxia and following addition of sodium lactate in vivo and in vitro. In the resting, well-oxygenated guinea pig, the mean plasma/red cell ratio of lactate was 1.55 and that of pyruvate 2.47. During asphyxia, the plasma/red cell ratio of lactate rose and that of pyruvate fell, indicating a delay in equilibration. Incomplete equilibration affected particularly the lactate/pyruvate ratio in the two compartments. Infused neutral sodium lactate penetrated the red cells at a rate comparable to that observed following endogenous release of lactic acid during acute asphyxia. In vitro at pH 6.8@#X2013;7.4 at 38 C, the time to 50% equilibration of lactate between plasma and cells of human blood was less than 2 min. It is concluded that during acute asphyxia and resuscitation whole blood values of lactate and pyruvate do not bear a constant relationship to those of plasma. lactate/pyruvate ratio Submitted on March 16, 1964