Interrelated effects of insulin and glucose on diacylglycerol-protein kinase-C signalling in rat adipocytes and solei muscle in vitro and in vivo in diabetic rats.

摘要: The effects of insulin and glucose, alone combined, on diacylglycerol (DAG), protein kinase-C (PKC), glucose transport were compared in rat adipocytes solei incubated medium containing 0-20 mM glucose. In both tissues rapidly stimulated [3H]DAG production from [3H]glycerol; extracellular masked this effect adipocytes, but not solei. [3H]Glucose was avidly converted to DAG conversion enhanced by insulin. contrast, [3H]glucose poorly Glucose (5-20 mM) PKC translocation Insulin at all concentrations. However, modulated 1) decreasing cytosolic the absolute amount translocated, 2) promoting apparent turnover membrane PKC. solei, did affect levels or responses keeping with DAG-PKC signalling, relative influenced These results suggest that glucose-induced requires metabolism DAG; activates signalling solei; 3) levels; 4) may modulate Consistent vitro results, taken directly diabetic rats, decreased, increased, presumably reflecting diminished due hypoinsulinemia. adipose tissue, hyperglycemia-induced translocation. Accordingly, increased tissues.