[Measurement of cytoplasmic Ca2+ activity in myocardia with Ca(2+)-sensitive microelectrode].
The improved neutral ligand ETH1001 Ca(2+)-sensitive microelectrodes (Ca-ISE, tip diameter 0.4-0.8 mumol.L-1) are highly ion selective and sensitive and therefore can be reliably used to measure cytoplasmic Ca2+ activity (alpha iCa) in myocardia. The resting alpha iCa 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 mumol.L-1. Three mumol.L-1 strophantin G increased the resting and dynamic myocardial alpha iCa by 0.18 +/- 0.02 and 6.69 +/- 2.09 mumol.L-1 respectively, as well as engendered triggered activity (TA). When pretreated with 100 mumol.L-1 dauricine (Dau), strophantin G could no longer increase alpha iCa and TA disappeared. It is suggested thus the applicability of Ca-ISE for measurement of myocardia alpha iCa and TA is obvious.
Wang
Z X
ZX
Department of Clinical Pharmacology, Tongji Medical University, Wuhan.
Zhu
J Q
JQ
Zeng
F D
FD
Hu
C J
CJ
Ma
Y L
YL
Zhong
S M
SM
D000470:Alkaloids; D000818:Animals; D044182:Benzylisoquinolines; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels; D004285:Dogs; D005260:Female; D006168:Guinea Pigs; D017736:Ion-Selective Electrodes; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials; D008839:Microelectrodes; D009206:Myocardium / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D010210:Papillary Muscles / Q000378:metabolism; D011690:Purkinje Fibers / Q000378:metabolism; D044005:Tetrahydroisoquinolines
D000470:Alkaloids; D044182:Benzylisoquinolines; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; D010042:Ouabain; C035934:dauricine; D002118:Calcium