Increased sensitivity of fat cell adenylate cyclase to stimulatory agonists during fasting is not related to impaired inhibitory coupling system

FEBS Letters

Agli, Brigitte¹  Lacasa, Daniéle¹  Giudicelli, Yves¹ 

[1] Service de Biochimie de la Faculté de Médecine Paris-Ouest, Centre Hospitalier de Poissy, 78303 Poissy Cedex, France

关键词: Adenylate cyclase;    Starvation;    Ni protein;    Nicotinic acid;    Hormonal sensitivity;    (Rat adipocyte);   

DOI  :  10.1016/0014-5793(86)80698-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In rat adipocytes, inhibition of the forskolin-stimulated cyclic AMP response by nicotinic acid and N ⁶-phenylisopropyladenosine was unaltered by a 72 h fasting. Under assay conditions favouring inhibition, basal and forskolin-stimulated adenylate cyclase responses to inhibition by GTP and nicotinic acid were also unimpaired by fasting. Under the same conditions, however, low GTP concentrations elicited a clear activatory effect in membranes from fasted but not from fed rats. Fasting failed to alter the incorporation of [³²P]ADP ribose into the α_i-subunit of N_i and the attenuation of nicotinic acid inhibitory action that are both induced by pertussis toxin. These results, demonstrating unimpaired inhibitory control of adenylate cyclase in starved rat adipocytes, suggest that the permissive effect of fasting on the action of stimulatory receptor agonists in fat cells reflects a specific increase in the activity of the adenylate cyclase stimulatory coupling system.

【 授权许可】

Unknown