Galanin increases cytoplasmic calcium in insulin-producing RINm5F cells by activating phospholipase C.
We showed previously that the neuropeptide, galanin, transiently and promptly increases the cytoplasmic concentration of Ca2+, [Ca2+]i, in insulin producing clonal RINm5F cells prior to a reduction in [Ca2+]i. We found that galanin (100 nM) transiently increased the [Ca2+]i in the presence of 15 mM glyceraldehyde and 3.3 mM glucose. This effect was abolished by both the inhibitor of the microsomal Ca2+ ATPase, thapsigargin, which depletes the intracellular Ca2+ stores, and the specific inhibitor of phospholipase C, U73122. In contrast, the blocker of L-type Ca2+ release, ryanodine, did not affect galanin-induced increase in [Ca2+]i. Thus, galanin induces a rapid mobilization of Ca2+ from intracellular Ca2+ stores in insulin producing RINm5F cells by an effect mediated by activated phospholipase C.
Ahrén
B
B
Department of Medicine, Lund University, Malmö, Sweden.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003593:Cytoplasm / Q000187:drug effects* / Q000378:metabolism; D004789:Enzyme Activation; D004963:Estrenes / Q000494:pharmacology; D019004:Galanin / Q000494:pharmacology*; D007328:Insulin / Q000096:biosynthesis*; D009543:Nifedipine / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D012433:Ryanodine / Q000494:pharmacology; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism*
D002121:Calcium Channel Blockers; D004963:Estrenes; D007328:Insulin; D011760:Pyrrolidinones; D013729:Terpenes; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D012433:Ryanodine; D019284:Thapsigargin; D019004:Galanin; D010738:Type C Phospholipases; D009543:Nifedipine; D002118:Calcium