title: Effects of volsartan on transmural heterogeneous changes of transient outward potassium currents in hypertrophic cardiomyocytes in rabbits.
abstract: The transmural heterogeneous changes of transient outward potassium currents (Ito) in rabbit hypertrophic cardiaomyocytes and the effects of long-term prophylactic treatment with volsartan were investigated. Rabbits were divided into hypertrophy group (left ventricular hypertrophy induced by partial ligation of abdominal aorta), vol-treated group (volsartan was administrated after the ligation), and control group (sham operated). Myocytes were isolated by a two-step enzymatical method. The sub-endocardial (Endo) and sub-epicardium (Epi) tissues were separated from midmyocardium (Mid) with a razor. Whole-cell patch-clamp technique was used to record potassium currents. The results showed that membrane capacitance was larger in hypertrophic cells than those in control and vol-treated cells (P<0.01 vs control cells, n=30). The densities of Ito in hypertrophic cells were reduced by sub-epicardium (Epi) (27.8 +/- 2.9) %, midmyocardium (Mid) (41.0+/-4.7) %, and sub-endocardium (Endo) (20.3 +/- 3.4) % compared with those in control cells. The decrease of Ito density was more pronounced in Mid than in Epi and Endo (P<0.01 vs Epi or Endo). There were no significant differences in Ito densities between vol-treated group and control group in three layers separately. In conclusion, volsartan can inhibit the transmural heterogeneous changes of Ito in left ventricular hypertrophic cardiomyocytes in rabbit.
authors.affiliation: Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Xiao
authors.forename: Hui
authors.initials: H
authors.lastname: Fu
authors.forename: Yexin
authors.initials: Y
authors.lastname: Ma
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Zaiying
authors.initials: Z
authors.lastname: Lu
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D005260:Female; D017379:Hypertrophy, Left Ventricular / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D032383:Myocytes, Cardiac / Q000473:pathology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects*; D011817:Rabbits; D013777:Tetrazoles / Q000494:pharmacology*; D014633:Valine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000068756:Valsartan
chemical_list: D000959:Antihypertensive Agents; D015221:Potassium Channels; D013777:Tetrazoles; D000068756:Valsartan; D014633:Valine