Vanadate-induced intracellular calcium elevation in the stria vascularis of the guinea pig: fluorescence ratio imaging microscopy.
Cytoplasmic free calcium has been observed in fura 2-loaded stria vascularis of the guinea pig. Following the application of vanadate, the cytosolic Ca2+ concentration increased by 45%. Complete substitution of extracellular Na+ with N-methyl D-glucamine did not alter the free calcium concentration. These findings suggest that the Ca2+ transport in the stria vascularis is mediated by a Ca2(+)-ATPase enzyme mechanism rather than Na(+)-Ca2+ exchange.
Ikeda
K
K
Department of Otolaryngology, Tohoku University School of Medicine, Sendai, Japan.
Saito
Y
Y
Takasaka
T
T
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives; D006168:Guinea Pigs; D008536:Meglumine; D008856:Microscopy, Fluorescence; D013316:Stria Vascularis / Q000187:drug effects / Q000378:metabolism*; D014638:Vanadates / Q000494:pharmacology*
D005456:Fluorescent Dyes; C049925:fura-2-am; D014638:Vanadates; D008536:Meglumine; D002118:Calcium; D016257:Fura-2