Electrically induced intracellular Ca2+ transient in single ventricular myocytes: a useful parameter for the study of cardiac drugs.
1. Fluorescent Ca2+ indicators, such as fura-2/AM and calcium green-1, have become one of the most popular tools for measuring intracellular calcium ([Ca2+]i). 2. Electrical stimulation triggers a cascade of events in the cardiac muscle, which results in a [Ca2+]i transient and, eventually, contraction. The events that occur in electrically induced cardiac myocytes mimic the normal physiological events in vivo. 3. The electrically induced [Ca2+]i transient represents influx of Ca2+ from outside and mobilization of Ca2+ from the intracellular store and is directly related to contraction. Thus, it is more important to determine the electrically induced [Ca2+]i transient than [Ca2+]i. The [Ca2+]i transient can be easily measured with the spectrofluorescence method using fura 2/AM as the Ca2+ indicator in a single ventricular myocyte preparation. 4. We made use of the results of studies on carbachol, tetrandrine and cardiotoxin to illustrate the usefulness of the electrically induced [Ca2+]i transient in the study of actions of cardiac drugs.
Wang
H X
HX
Department of Pharmacology, Jin Zhou Medical College, Jin Zhou, China. xinhwang@public2.jzptt.ln.cn
Kwan
C Y
CY
Wong
T M
TM
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004558:Electric Stimulation; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects; D016276:Ventricular Function
D002316:Cardiotonic Agents; D002118:Calcium