Antibody to the inositol trisphosphate receptor blocks thimerosal-enhanced Ca(2+)-induced Ca2+ release and Ca2+ oscillations in hamster eggs.
The sulfhydryl reagent thimerosal enhanced the sensitivity of hamster eggs to injected inositol 1,4,5-trisphosphate (InsP3) or Ca2+ to generate regenerative Ca2+ release from intracellular pools. A monoclonal antibody (mAb) to the InsP3 receptor blocked both the InsP3-induced Ca2+ release (IICR) and Ca(2+)-induced Ca2+ release (CICR). The mAb also blocked Ca2+ oscillations induced by thimerosal. The results indicate that thimerosal enhances IICR sensitized by cytosolic Ca2+, but not CICR from InsP3-insensitive pools, and causes repetitive Ca2+ releases from InsP3-sensitive pools.
Miyazaki
S
S
Department of Physiology, Tokyo Women's Medical College, Japan.
Shirakawa
H
H
Nakada
K
K
Honda
Y
Y
Yuzaki
M
M
Nakade
S
S
Mikoshiba
K
K
D000818:Animals; D000911:Antibodies, Monoclonal; D001683:Biological Clocks; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D006224:Cricetinae; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D010063:Ovum / Q000187:drug effects* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000276:immunology* / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear; D013849:Thimerosal / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D013849:Thimerosal; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium