Inhibitory effect and mode of action of somatostatin on lipolysis in chicken adipocytes.
The effect of somatostatin on lipolysis was investigated utilizing isolated chicken adipocytes. Somatostatin-14 and -28 inhibited basal lipolysis. This ability to suppress glycerol release (used as an index of lipolysis) was emphasized in presence of stimulated lipolysis. Concentration of 1 ng/ml somatostatin-14 (0.625 nM) and somatostatin-28 (0.312 nM) was found to inhibit completely the glycerol release induced by concentrations of glucagon up to 2 ng/ml (0.58 nM). The percentage of inhibition was dose-dependent. The antilipolytic effect of somatostatin-14 was also observed during ACTH and aminophylline-stimulated lipolysis. Among the mechanisms which could account for the inhibition, a possible competitive effect of somatostatin-14 with 125I-labelled glucagon binding to adipocyte membranes was excluded. The small inhibiting effect of somatostatin-14 on glycerol release prompted by dibutyryl cyclic AMP, together with the significant inhibiting effect on aminophylline-stimulated lipolysis argued for a reduction of cyclic AMP accumulation. The increase of cyclic AMP levels induced by glucagon was substantially reduced in presence of somatostatin-14. It was concluded that in chicken adipocytes somatostatin inhibited the rate of lipolysis and that reduction on cyclic AMP could be responsible, at least in part, for the antilipolytic effect.
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000628:Aminophylline / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D005990:Glycerol / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects*; D013004:Somatostatin / Q000494:pharmacology*; D053561:Somatostatin-28
D000628:Aminophylline; D013004:Somatostatin; D003994:Bucladesine; D053561:Somatostatin-28; D005990:Glycerol