| Abstract: | The effects of various Ca 2 modifying drugs on moue egg fertilization were studied.Ca 2 chelator,ethylen glycol bis (2 aminoethyl) tetracetic acid(EGTA),and calmodulin (CaM) antagonist,trifluoperzaine(TFP),inhibited fertilization in a dose dependent manner,whild Ca 2 channel bolcker,verapamil,did not have any effect.When intracellular Ca 2 release was blocked by 8 (N,N diethylamino) octy1 3,4, 5 trimethoxybenzonate(TMB 8) or the Ca 2 oscillations were inhibited by an inhibitor of endoplasmic reticulum Ca 2 ATPase,thapsigargin,the second polar body emission and pronuclear formation were significantly decreased.In contrast,inhibition of intracellular Ca 2 release via bolckage of inositol 1,4,5 triphosphate (IP3) production by neomycin or lithium did not affect fertilization.The results sugest that both extracellular influx,intracellular Ca 2 release and CaM activation are required for normal fertilization.However,extracellular influx through voltage gated Ca 2 channel and intracellular release induced by IP3 are not the only pathways for producing Ca 2 transients in moue eggs. |
