Stimulation of hepatic glycogenolysis by acetylglyceryl ether phosphorylcholine.
1-O-Alkyl-2-acetyl-sn-glyceryl 3-phosphorylcholine or acetylglyceryl ether phosphorylcholine (AGEPC) stimulated glycogenolysis in perfused livers from fed rats at concentrations as low as 10(-11) M. At the lower AGEPC concentrations, e.g. 2 X 10(-10) M, a single transient phase of enhanced hepatic glucose output was elicited upon infusion of this agonist. At higher concentrations, e.g. 2 X 10(-8) M, a sharp transient spike of glucose output was observed, followed by a stable elevated steady state rate of glucose output until the AGEPC infusion was terminated. Increased rates of lactate and acetoacetate output and a diminished hepatic oxygen consumption were characteristic of the response of the livers to AGEPC at 2 X 10(-10) M. Neither alpha- nor beta-adrenergic antagonists blocked the glycogenolytic response of AGEPC. Repeated infusion of AGEPC led to homologous desensitization of the response, but the response of the liver to the alpha-adrenergic agonist, phenylephrine, or to glucagon, subsequent to AGEPC stimulation, was unaffected. Increasing the period of perfusion between successive additions of AGEPC, from 7 to 30 min, resulted in an increased glycogenolytic response to this agonist. When the perfusate calcium concentration was reduced from 1.25 to 0.05 mM, the glycogenolytic response to AGEPC was markedly diminished; calcium efflux from the liver following stimulation with AGEPC was not observed. The data presented in this study illustrate a potent agonist effect of AGEPC on the glycogenolytic system in the rat liver.
D000818:Animals; D007700:Kinetics; D008099:Liver / Q000187:drug effects*; D008112:Liver Glycogen / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D010656:Phenylephrine / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D008112:Liver Glycogen; D010972:Platelet Activating Factor; D010656:Phenylephrine; D012710:Serum Albumin, Bovine