Heterogeneity of action potential and ion currents in the left ventricular myocytes of the rabbit.
- Author:
Yang LI
1
;
Jie MA
;
Jian-Min XIAO
;
Nian LIU
;
Hui-Yan NIU
;
Zai-Ying LU
Author Information
1. Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. liyang40@hotmail.com
- Publication Type:Journal Article
- MeSH:
Action Potentials;
physiology;
Animals;
Calcium Channels;
physiology;
Female;
Heart Ventricles;
cytology;
Male;
Myocytes, Cardiac;
cytology;
metabolism;
physiology;
Patch-Clamp Techniques;
Potassium Channels;
physiology;
Rabbits
- From:
Acta Physiologica Sinica
2002;54(5):369-374
- CountryChina
- Language:Chinese
-
Abstract:
Experiments were performed to investigate the heterogeneity of the action potential and ion currents in left ventricular myocytes of the rabbit. Myocytes were isolated by enzymatic method. The sub-endocardial (Endo) and sub-epicardium (Epi) tissues were separated from the other region (midmyocardium, M) with a razor. Single cells in each region were obtained by gentle shaking and dispersing in a chamber filled with normal Tyrode's solution. The results showed that the action potential and the ion currents in the three layers were significantly different. M cells had a more pronounced spike-and-dome configuration, with a significantly larger phase 1 magnitude and plateau voltage. Action potential duration (APD) in M cells was longer than that in Epi or Endo cells. I(Ca, L) and I(to) in M cells were higher than those of Epi and Endo. On the contrary, I(K,s) in M cells was the minimum compared with those in the three LV walls. The differences in ion currents may well explain the heterogeneity of action potentials in M layers of the rabbit heart.
