Blood pyruvate concentration measured by a specific method in control subjects.

A specific method of estimating pyruvate, depending upon the oxidation of reduced nicotinamide-adenine dinucleotide in the presence of lactic dehydrogenase, has been modified to improve its accuracy. The precision of the modification, measured by duplicate analysis, was represented by a standard deviation of 0.03 mg./100 ml. The mean recovery of added pyruvate was 99%. The mean blood pyruvate concentration in 30 fasted subjects, who had no illness known to affect pyruvate metabolism, was 0.44 mg./100 ml. (S.D. 0.05). Blood pyruvate levels were measured at 30-minute intervals for two hours after oral or intravenous administration of glucose. The highest levels obtained in each case were about 0.4 mg./100 ml. higher than the initial level, and were found 60 to 90 minutes after oral administration and 30 to 60 minutes after intravenous administration.