Effects of stress on L type calcium channels of rat ventricular myocytes.
- Author:
Jun XU
1
;
Qiang MA
;
Hai-Feng DUAN
;
Ling-Jia QIAN
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Apoptosis; Calcium Channels, L-Type; metabolism; Cells, Cultured; Heart Ventricles; cytology; Male; Myocytes, Cardiac; cytology; metabolism; Patch-Clamp Techniques; Rats; Rats, Wistar; Stress, Physiological
- From: Chinese Journal of Applied Physiology 2003;19(3):216-220
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo observe the effects of stress on Ica-L, steady-state activation curves and steady-state inactivation curves.
METHODSUse NE to construct stress cell model, then the whole-cell patch-clamp recording technique was used to record the Ica-L, the steady-state activation curves and the steady-state inactivation curves. With FCM technique, we observed the rate of apoptosis of cardiomyocytes. By dying cells with Fura-2 and fluorometry, we determined [Ca2+]i.
RESULTSThe amplitude of peak current of Ica-L increased significantly, and by analyzing the steady-state activation curve, we found that the curve was shifted to left, the V1/2 of stress group was (-14.59 +/- 0.24 ) mV vs (-0.69 +/- 0.36) mV of control group. The rate of apoptosis was increased from 0.36% to 2.17% (P < 0.01). The [Ca2+]i increased by 16.7%.
CONCLUSIONStress can bring on increasing of Ica-L, and the channels are easy to be activated. These changes can cause "calcium overload" and then induce apoptosis which lead to injury of myocytes in stress.
