Stimulation by glucose and carbamylcholine of phospholipase A2 in pancreatic islets.
Glucose, in high concentrations (16.7-27.8 mM), caused a modest increase in effluent radioactivity from rat pancreatic islets prelabelled with [U-14C] arachidonate. The response to glucose was abolished in the absence of extracellular Ca2+. At a low glucose concentration (5.6 mM), carbamylcholine (1.0 mM) provoked a more marked and sustained increase in effluent radioactivity. The response to the cholinergic agent was abolished in the presence of atropine or absence of extracellular Ca2+. These results suggest that carbamylcholine and, to a lesser extent, glucose cause a Ca2+-dependent activation of phospholipase A2 in intact islet cells.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology*; D002250:Carbon Radioisotopes; D004789:Enzyme Activation; D005947:Glucose / Q000494:pharmacology*; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000201:enzymology*; D007700:Kinetics; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2
D001095:Arachidonic Acids; D002250:Carbon Radioisotopes; D016718:Arachidonic Acid; D002217:Carbachol; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D005947:Glucose