Glycogenolytic, noninsulin-like effects of vanadate on rat hepatocyte glycogen synthase and phosphorylase
Bosch i Tubert, Fàtima (Universitat Autònoma de Barcelona. Departament de Bioquímica i de Biologia Molecular)
Ariño Carmona, Joaquín (Universitat Autònoma de Barcelona. Departament de Bioquímica i de Biologia Molecular)
Gómez-Foix, Anna María (Universitat Autònoma de Barcelona. Departament de Bioquímica i de Biologia Molecular)
Guinovart Cirera, Joan J (Universitat Autònoma de Barcelona. Departament de Bioquímica i de Biologia Molecular)

Date:	1987
Abstract:	Vanadate inactivated rat hepatocyte glycogen synthase and activated glycogen phosphorylase in a dose- and time-dependent manner. These effects were observed in hepatocytes from both fasted as well as fed rats. When rat hepatocytes were preincubated with [32P]phosphate and then with vanadate, and the 32P-labeled glycogen synthase was specifically immunoprecipitated, it was observed that vanadate stimulated the phosphorylation of the 88,000-dalton subunit of glycogen synthase. All of the phosphate was located in the same two CNBr fragments of the enzyme which are phosphorylated by glucagon and other glycogenolytic hormones. In cells incubated in a calcium-depleted medium, vanadate was still able to inactivate glycogen synthase but its effects on phosphorylase were essentially lost. These results demonstrate that, in the hepatocyte, vanadate exerts opposite effects than in the adipocyte and skeletal muscle, where vanadate has an insulin-like action.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	Journal of biological chemistry, Vol. 262 Núm. 1 (1987) , p. 218-222, ISSN 1083-351X

5 p, 1.8 MB

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