Selective stimulation of Ca2+ flux in cells by maitotoxin.
Maitotoxin elicits a dose-dependent stimulation of 45Ca2+ influx in glioma C6, pheochromocytoma PC12, insulinoma HIT and human blood cells, while having no effect in liposomes. In HIT cells maitotoxin also elicited influx of 86Rb+ greater than 22Na+ greater than 54Mn2+, but the stimulation was far less than for 45Ca2+. Stimulation of 45Ca2+ influx was blocked by Ni2+, Co2+, Cd2+ and Mn2+, and markedly reduced by Ba2+. Divalent cations, in particular Ca2+, Ba2+, Mn2+ and Cd2+, enhanced influx of the monovalent cations 22Na+ and 86Rb+.
Murata
M
M
Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, MD 20892.
Gusovsky
F
F
Yasumoto
T
T
Daly
J W
JW
D000818:Animals; D002118:Calcium / Q000097:blood / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects; D002132:Calcium Radioisotopes; D002412:Cations; D002713:Chlorine / Q000378:metabolism; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D008081:Liposomes / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D008387:Marine Toxins / Q000494:pharmacology*; D035964:Oxocins; D011868:Radioisotopes; D051381:Rats; D012414:Rubidium Radioisotopes; D012979:Sodium Radioisotopes; D014407:Tumor Cells, Cultured; D000095702:Polyether Toxins
D002118:Calcium; D015220:Calcium Channels; D002132:Calcium Radioisotopes; D002412:Cations; D002713:Chlorine; D008081:Liposomes; D008345:Manganese; D008387:Marine Toxins; D035964:Oxocins; D011868:Radioisotopes; D012414:Rubidium Radioisotopes; D012979:Sodium Radioisotopes; C020394:maitotoxin; D000095702:Polyether Toxins