Adenylate cyclase activity in the epididymal adipose tissue from obese-hyperglycaemic mice

The adenylate cyclase activities in 1,500 × g to 25,000 × g sediments of adipose tissue from 3 month old C57BL 6J/ob and lean mice were compared. Three anomalies were observed in obese mice: 1) a defect in basal (-80%) and fluoridestimulated (-50%) activities suggesting a decreased number of catalytic units per mg protein; 2) an impairment in stimulation by isoproterenol (-85%) with no change in apparent affinity for the hormone; and, 3) no stimulatory effect of ethanol upon guanyl nucleotide-stimulated activity. The two latter effects may be due to a reduced number of β-adrenergic receptors per mg protein and/or to an alteration in the transducing process. On the other hand, guanyl nucleotides as well as prostaglandin PGE1 exerted similar effects in the preparations from both lean and obese adipose tissue. © 1978 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe