Ciguatoxin, extracted from poisonous morays eels, causes sodium-dependent calcium mobilization in NG108-15 neuroblastoma x glioma hybrid cells.
Measurement of intracellular Ca2+ concentration ([Ca2+]i) in cultured mouse NG108-15 neuroblastoma x glioma hybrid cells, using the fluorescent probe fura-2, revealed that 5-25 nM ciguatoxin (CTX) increased [Ca2+]i either in cells bathed in standard medium or after removal of external Ca2+ by a Ca(2+)-free medium supplemented with EGTA. Tetrodotoxin prevented the CTX increased [Ca2+]i suggesting that CTX-induced mobilization of intracellular Ca2+ depends on Na+ influx through voltage-gated Na channels. CTX-induced Ca2+ mobilization prevented subsequent action of bradykinin (1 microM) suggesting that CTX stimulates the inositol 1,4,5-trisphosphate-releasable Ca2+ store.
Molgó
J
J
Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, Gif sur Yvette, France.
Shimahara
T
T
Legrand
A M
AM
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002922:Ciguatoxins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004524:Eels / Q000502:physiology*; D005470:Fluorometry; D016257:Fura-2; D005910:Glioma / Q000378:metabolism*; D006822:Hybrid Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D002922:Ciguatoxins; D013779:Tetrodotoxin; D012964:Sodium; D001920:Bradykinin; D002118:Calcium; D016257:Fura-2