Characteristics of the desensitization and resensitization of the cyclic AMP-independent glycogenolytic response in rat liver cells.
Vasopressin and alpha-adrenergic agonists were shown previously [Bréant, Keppens & De Wulf (1981) Biochem. J. 200, 509-514] to induce a heterologous, dose-dependent and receptor-mediated desensitization of the cyclic AMP-independent glycogenolytic response in isolated hepatocytes. The desensitized state of the hepatocytes can be preserved as long as the agonist is bound to its receptor. Conversely, washing the cells with a hormone-free buffer or displacement of the agonist from its receptor by a specific antagonist restores the responsiveness. The desensitization and its reversibility (i.e. resensitization) are obtained within minutes. The desensitization can be clearly elicited at temperatures as low as 5 degrees C, whereas the glycogenolytic response and the enhancement of the 45Ca flux are only obtained above 15 degrees C; the resensitization requires even higher temperatures. A tentative model is proposed to account for the observed effects.
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007700:Kinetics; D007811:Lanthanum / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008112:Liver Glycogen / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D010656:Phenylephrine / Q000494:pharmacology; D006005:Phosphorylases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014667:Vasopressins / Q000494:pharmacology*
D008112:Liver Glycogen; C028521:lanthanum chloride; D014667:Vasopressins; D000804:Angiotensin II; D010656:Phenylephrine; D007811:Lanthanum; D000242:Cyclic AMP; D006005:Phosphorylases