Differences in Ca2+ mobilization induced by alpha-adrenergic agonist and phosphatidic acid in cultured hepatocytes.
In an attempt to elucidate the relationship between phosphatidylinositol breakdown and alpha-adrenergic responses, effects of phosphatidic acid and phosphatidylinositol related metabolites on Ca2+ mobilization and glucose output in cultured hepatocytes were examined. Norepinephrine induced the net 45Ca2+ efflux from preloaded cells and stimulated glucose output via alpha-adrenergic receptor stimulation, whereas phosphatidic acid caused 45Ca2+ uptake to cells and did not stimulate glucose output. Myo-inositol-monophosphate, diglyceride and arachidonic acid, which are released by phosphatidylinositol breakdown, had no effect on 45Ca2+ efflux and glucose output in cells. These results suggest that phosphatidic acid and phosphatidylinositol related metabolites can not mimic the alpha-adrenergic actions in cultured hepatocytes.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010712:Phosphatidic Acids / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000494:pharmacology*; D011224:Prazosin / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D010712:Phosphatidic Acids; D010716:Phosphatidylinositols; D011799:Quinazolines; D011433:Propranolol; D005947:Glucose; D002118:Calcium; D009638:Norepinephrine; D011224:Prazosin