[The feasibility exploration of cultured newborn rat ventricular myocyte taking the place of acutely enzymatic isolated myocardium for study in electrophysiology of pacemaker current].
OBJECTIVE
To investigate the feasibility of cultured rat ventricular myocytes taking the place of acutely enzymatic isolated myocardia for study in the pacemaker current electrophysiology.


METHODS
By using patch-clamp technique, the whole-cell pacemaker currents were recorded to study the difference of pacemaker current electrophysiology between neonatal rat ventricular myocytes isolated acutely and maintained in cell culture.


RESULTS
The cell membrane capacitances (Cm) were significantly decreased in myocardia even upon short term of cell culture. The Cm of myocardia cultured 1-3 day were (43 +/- 3) pF, with decreased 23% compared to acute enzymatic isolated cells C(56+/-7) pF, P<0. 013. It seemed like the Cm increased slightly upon cell cultured time, but no significant difference appearing among various culture stages (P > 0. 05) . No significant difference of pacemaker current electrophysiological character, such as reverse potential, current density, active threshold and V0.5, was detected from different cell group (P>0. 05).


CONCLUSIONS
The cultured myocardium can take place of acute enzymatic isolated myocardium used to study in pacemaker current. The cells cultured no more than one week may be more suitable to this kind of electrophysiological experiment.
Jia
Wei-guo
WG
Department of Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China.
Deng
Jue-lin
JL
Liao
Da-qing
DQ
Li
Miao-ling
ML
Zeng
Xiao-rong
XR
Huang
De-jia
DJ
D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000378:metabolism; D002469:Cell Separation; D002478:Cells, Cultured; D025802:Electric Capacitance; D004553:Electric Conductivity; D055724:Electrophysiological Phenomena; D004798:Enzymes / Q000378:metabolism*; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000166:cytology; D008297:Male; D032342:Muscle Cells / Q000166:cytology*; D009206:Myocardium / Q000166:cytology*; D010138:Pacemaker, Artificial; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D016276:Ventricular Function
D004798:Enzymes