Two types of insulin receptors mediating opposite effects on cyclic-amp in fat cells of the rat.

Abstract

The article states that a direct effect of insulin on the fat cell is to lower intracellular levels of adenosine 3',5' monophosphate (cyclic AMP), previously stimulated with catecholamines. It was found that insulin lowers the levels of cyclic AMP in adipose cells stimulated with isoprenaline; but that if cells are pretreated with trypsin the same concentration of insulin now elevates levels of cyclic AMP. Adipocytes were prepared from epididymal pads of rats and, after preincubation with trypsin or N methylmaleimide (NEM) for 15 minutes, they were dispensed into polystyrene tubes containing 0.3 ml of Earles buffer with glucose (2 mM), theophylline (3 mM) and crystalline albumin (1% w/v). Is..