title: [Heterogeneity of action potential and ion currents in the left ventricular myocytes of the rabbit].
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.
authors.affiliation: Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. liyang40@hotmail.com
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Xiao
authors.forename: Nian
authors.initials: N
authors.lastname: Liu
authors.forename: Hui-Yan
authors.initials: HY
authors.lastname: Niu
authors.forename: Zai-Ying
authors.initials: ZY
authors.lastname: Lu
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D005260:Female; D006352:Heart Ventricles / Q000166:cytology; D008297:Male; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism* / Q000502:physiology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology; D011817:Rabbits
chemical_list: D015220:Calcium Channels; D015221:Potassium Channels