Regulation of renal gluconeogenesis by calcium ions, hormones and adenosine 3':5'-cyclic monophosphate.
1. The effect of Ca(2+), glucagon, adrenaline and adenosine 3':5'-cyclic monophosphate on gluconeogenesis by rat kidney-cortex slices was studied. 2. Glucose formation from a range of substrates, with the exception of glycerol, was increased by an increase in extracellular Ca(2+) concentration. 3. Hormones and adenosine 3':5'-cyclic monophosphate, at low Ca(2+) concentrations, stimulated glucose production from several substrates, but not from glycerol, fructose, malate or fumarate. 4. Hormonal stimulation was not detected in the absence of Ca(2+) or at 2.5mm-Ca(2+). 5. Ca(2+), hormones and adenosine 3':5'-cyclic monophosphate had no effect on phosphoenolpyruvate carboxylase activity. 6. It is proposed that Ca(2+) and adenosine 3':5'-cyclic monophosphate-mediated hormone action activate the same rate-limiting step in gluconeogenesis: this step is tentatively identified as the rate of transfer of substrates across the mitochondrial membrane.
D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D000242:Cyclic AMP / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology*; D005650:Fumarates / Q000378:metabolism; D005934:Glucagon / Q000494:pharmacology*; D005943:Gluconeogenesis / Q000187:drug effects*; D005973:Glutamine / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D007672:Kidney Cortex / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D007700:Kinetics; D007773:Lactates / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000378:metabolism; D051381:Rats; D013056:Spectrophotometry, Ultraviolet; D013217:Starvation; D013386:Succinates / Q000378:metabolism
D002087:Butyrates; D005650:Fumarates; D007773:Lactates; D008293:Malates; D013386:Succinates; D005973:Glutamine; D005934:Glucagon; D000242:Cyclic AMP; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D002118:Calcium; D004837:Epinephrine