title: [Effects of stress on L type calcium channels of rat ventricular myocytes].
abstract: OBJECTIVE
  To observe the effects of stress on Ica-L, steady-state activation curves and steady-state inactivation curves.
  
  
  METHODS
  Use 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.
  
  
  RESULTS
  The 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%.
  
  
  CONCLUSIONS
  Stress 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.
authors.affiliation: Institute of Health and Environmental Medicine, Academy of Military Medical Sciences, Tianjin 300050, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ma
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Duan
authors.forename: Ling-Jia
authors.initials: LJ
authors.lastname: Qian
mesh_terms: D000818:Animals; D017209:Apoptosis; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D002478:Cells, Cultured; D006352:Heart Ventricles / Q000166:cytology*; D008297:Male; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological
chemical_list: D020746:Calcium Channels, L-Type