Correction by Dexamethasone Treatment of the Altered Lipolytic Cascade Induced by Adrenalectomy in Rat Adipocytes

Summary

The ability of glucocorticoid-treatment to reverse the metabolic alterations caused by adrenalectomy in rat adipocytes was studied. Correction of the enhanced adenosine antilipolytic effect and of the defect in lipolysis, cyclic AMP and adenylate cyclase responsiveness to guanine nucleotides were all achieved after a 24 h dexamethasone treatment, whereas correction of the defect in β-adrenoceptor-density required a 48 h treatment. The latter treatment, however, failed to reverse the defect in both the adenylate cyclase catalytic activity and protein content per fat cell. These different kinetics of restoration indicate that correction by dexamethasone of the defective cyclic AMP and lipolytic responses on one hand and of the guanine nucleotide control of adenylate cyclase on the other one are two related phenomenoms.

Key words

Adrenalectomy - Glucocorticoids - Adipocytes - Adenylate Cyclase - β-Adrenoceptors - Lipolysis