Mode of action of adrenal cortical hormones. 3. Stimulation of 14C incorporation from 14CO2 and 14C-pyruvate into glucose by triamcinolone in the presence of ethanol in rat liver slices.

Abstract

1. The effect of triamcinolone on the incorporation of 14C from 14CO2 and 14C-pyruvate into glucose and on the incorporation of pyruvate carbon into fatty acids and CO2 in rat liver slices was studied in the presence of sufficient amount of ethanol which inhibits gluconeogensis. 2. Ethanol is known to inhibit gluconeogenesis and the oxidation of pyruvate, glucose, and various amino acids in the liver by increasing the generation of NADH2. In fact, ethanol inhibition to the 14C incorporation from 14CO2 and 14C-pyruvate into glucose in rat liver slices was observed in the present investigation. The incorporation of 14C from 14C-pyruvate into fatty acids and CO2was also inhibited by ethanol. 3. Triamcinolone stimulated the 14C incorporation from 14CO2and 14C-pyruvate into glucose, but not the 14C incorporation into CO2and fatty acids. 4. Methylene blue, which is a redox dye capable of oxidizing NADH2, restored all these ethanol inhibitions. Triamcinolone counteracted the ethanol inhibition of 14C incorporation from 14CO2and 14C-pyruvate into glucose, but triamcinolone did not affect the ethanol inhibition of 14C incorporation from 14C-pyruvate into CO2 and fatty acids. Therefore, it is unlikely that the effect of adrenal cortical hormones to stimulate gluconeogenesis is primarily on the NADH2/NAD system.