Distinctive effects of glucagon on gluconeogenesis and ketogenesis in hepatocytes isolated from normal and biotin-deficient rats.
In hepatocytes from 48 h-starved rats identical glucagon dose-response curves were obtained for the stimulation of gluconeogenesis from lactate, for ketogenesis and for the decreasing of the C5-dicarboxylate pool. Glucagon (20 nM) caused a 5-fold increase in 3-hydroxybutyrate formation, but decreased acetoacetate production 50% of that of the control. In hepatocytes from biotin-deficient rats glucagon no longer stimulated gluconeogenesis from lactate, but still produced its effects on the mitochondrial redox state and the C5-dicarboxylate pool. The results suggest that the primary site of the hormone action on gluconeogenesis is located within the mitochondria rather than in the cytosol.
D000818:Animals; D001710:Biotin / Q000172:deficiency*; D004305:Dose-Response Relationship, Drug; D005934:Glucagon / Q000494:pharmacology*; D005943:Gluconeogenesis / Q000187:drug effects*; D066298:In Vitro Techniques; D007657:Ketone Bodies / Q000096:biosynthesis*; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats
D007657:Ketone Bodies; D001710:Biotin; D005934:Glucagon