from analysis of these data we determined ( a ) gluconeogenesis proceeds at half the basal rate in the presence of a large infused glucose load , ( b ) one-quarter of the hepatic pyruvate pool is derived from nonglucose carbon , ( c ) half of the labeled molecules in liver glycogen are of mass 186 from the infused glucose and half are of masses 181-183 , ( d ) the contribution of the indirect path from pyruvate when corrected for synthesis from unlabeled pyruvate ranges from 55 to 65 % , ( e ) the rate of pyruvate carboxylase averages 90 % that of citrate synthase , and ( f ) the rate of exchange of oxaloacetate with fumarate is about three times the rate of flux in the krebs cycle ( four times in the `` '' forward '' '' direction ) , and the enrichment in carbon 1 of oxaloacetate was 2.3 times that in carbon 4 .
C0017715
gluconeogenesis
C0017725
glucose