Blood Lactic Acid in Rats and Men: Comparison of Normo- and Hypertensive Individuals

Summary Among rats from two strains with opposite genetic predisposition to experimental hypertension, lactic acid concentrations in the blood were equivalent. Lactic acid concentration could not be correlated with the presence or absence of overt hypertension. Blood lactic acid values in these rats were comparable to those in man. In confimation of reports by others, among humans the average blood lactic acid value of a small group of hypertensive patients was increased as compared with the average value of an appropriate control group. Lactic acid concentration in all samples increased when the blood was allowed to stand at room temperature. This increase was larger in rat blood than in human samples and, in man, it increased faster in hypertensive patients than in controls. It is proposed that these differences may reflect ion transport activity by the red cell, and that the difference between man and rat is related to the dissimilar surface-to-volume ratio of the cells.