%0 Journal Article
%T Relationship between plasma membrane Ca2+-ATPase activity and acrosome reaction in guinea pig sperm<br>
%A LI Mingwen
%A CHEN Dayuan
%A <br>
%J 中国科学C辑(英文版)
%D 1996
%I Springer
%X The results obtained by biochemical measurement demonstrated for the first time that significant decrease of the plasma membrane Ca2+-ATPase activity occurred during capacitation and acrosome reaction of guinea pig sperm. Ethaorynic acid, one kind of Ca2+-ATPase antagonists, inhibited the plasma membrane Ca2+-ATPase activity, but calmodulin (50μg/mL) and trifluoperazine (200- 500μmol/L) did not, suggesting that calmodulin is not involved in ATP-driven Ca2+ efflux from sperm. However, calmodulin is involved in the control of Ca2+ influx. TFP, one kind of calmodulin antagonists, accelerated the acrosome reaction and Ca2+ uptake into sperm cells significantly. Ca2+-ATPase antagonists, quercetin, sodium orthovandate, furosemide and ethacrynic acid promoted the acrosome reaction, but inhibited Ca2+ uptake, which cannot be explained by their inhibitory effects on the plasma membrane Ca2+-ATPase activity. It is speculated that this phenomenon might be caused by simultaneous inhibitions of the activities of Ca2+-ATPase present in the plasma membrane, the outer acrosome membrane and the outer mitochondrion membrane resulting in Ca2+ accumulation in the cytoplasm, which in turn blocks further Ca2+ entry through some negative feedback mechanism(s). The inhibitory effect of Ca2+-ATPase antagonist on glycolytic activity may also be the reason for Ca2+ accumulation in cytoplasm and inhibition of Ca2+ uptake.
%K guinea pig
%K sperm
%K Ca2+-ATPase
%K Ca2+ uptake
%K acrosome reaction<br>
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=180CF3A72E750F3261A8A60EDC957784&aid=90063D7E2343505F97F5F053AD29F134&yid=8A15F8B0AA0E5323&vid=7C3A4C1EE6A45749&iid=E158A972A605785F&sid=6B3068A7C27BD349&eid=BA48F0B914ED890A&journal_id=1674-7305&journal_name=ScienceChina.Lifesciences&referenced_num=0&reference_num=0