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Measurement of cytoplasmic Ca~(2+)activity in myocardia with Ca~(2+)-sensitive microelectrode

Wang Zhenxin, Zhu Jiequan, Zeng Fandian, Hu Chongjia, Ma Yilong, Zhong Shiming

Department of Clinical Pharmacology, Tongji Medical University. Wuhan,Hubei；China(430030)

Abstract

The improved neutral ligand ETH_(1001) Ca~(2+)-sensitive microelectrodes (Ca-ISE, tip diameter 0.4-0.8#mu#mol·L~(-1)are highly ion selective and sensitive and there fore can be reliably used to measure cytoplasmic Ca~(2+)activity(#alpha#_(Ca)~(i)in myocardia. The resting #alpha#_(Ca)~(i)in guinea-pig ventricular trabecula, canine ventricular myocardia and Purkinje fibers were respectively 0.19±0.01, 0.20±0.02 and 0.46±0.07#mu#mol·L~(-1). Three #mu#mol·L~(-1)strophantin G increased the resting and dynamic myocardial #alpha#_(Ca)~(i)by 0.18±0.02 and 6.69±2.09#mu#mol·L~(-1)respectively, as well as engendered triggered activity(TA). When pretreated with 100 #mu#mol·L~(-1)dauricine(Dau), strophantin G could no longer increase #alpha#_(Ca)~(i) and TA disappeared. It is suggested thus the applicability of Ca-ISE for measurement of myocardia #alpha#_(Ca)~(i)and TA is obvious.

Key words: Neutral ligand Ca~(2+)-sensitive;Microelectrode cytoplasmic Ca~(2+) activity; Strophantin G;Triggered;Activity

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Citing This Article：

Wang Zhenxin, Zhu Jiequan, Zeng Fandian, Hu Chongjia, Ma Yilong, Zhong Shiming. Measurement of cytoplasmic Ca~(2+)activity in myocardia with Ca~(2+)-sensitive microelectrode. Acta Physiol Sin 1994; 46 (4): (in Chinese with English abstract).