Remodeling excitation-contraction coupling of hypertrophied ventricular myocytes is dependent on T-type calcium channels expression

Satoshi Takebayashi, Yulong Li, Toshihiko Kaku, Shuichiro Inagaki, Yutaka Hashimoto, Kazuhiro Kimura, Shinji Miyamoto, Tetsuo Hadama, Katsushige Ono

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

We utilized Wistar rats with monocrotaline (MCT)-induced right ventricular hypertrophy (RVH) in order to evaluate the T-type Ca2+ channel current (ICaT) for myocardial contraction. RT-PCR provides that mRNA for T-type Ca2+ channel α1-subunits in hypertrophied myocytes was significantly higher than those in control rats (α1G; 264 ± 36%, α1H; 191 ± 34%; P < 0.05). By whole-cell patch-clamp study, ICaT was recorded only in hypertrophied myocytes but not in control myocytes. The application of 50 nmol/L nifedipine reduced the twitch tension of the right ventricles equally in the control and RVH rats. On the other hand, 0.5 μmol/L mibefradil, a T-type Ca2+ channel blocker, strongly inhibited the twitch tension of the RVH muscle (control 6.4 ± 0.8% vs. RVH 20.0 ± 2.3% at 5 Hz; P < 0.01). In conclusion, our results indicate the functional expression of T-type Ca2+ channels in the hypertrophied heart and their contribution to the remodeling of excitation-contraction coupling in the cardiac myocyte.

Original languageEnglish (US)
Pages (from-to)766-773
Number of pages8
JournalBiochemical and Biophysical Research Communications
Volume345
Issue number2
DOIs
StatePublished - Jun 30 2006

Fingerprint

T-Type Calcium Channels
Right Ventricular Hypertrophy
Excitation Contraction Coupling
Muscle Cells
Rats
Mibefradil
Rat control
Monocrotaline
Clamping devices
Nifedipine
Myocardial Contraction
Muscle
Cardiac Myocytes
Heart Ventricles
Wistar Rats
Messenger RNA
Muscles
Polymerase Chain Reaction

Keywords

  • E-C coupling
  • Hypertrophy
  • Remodeling
  • T-type Ca channels

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Remodeling excitation-contraction coupling of hypertrophied ventricular myocytes is dependent on T-type calcium channels expression. / Takebayashi, Satoshi; Li, Yulong; Kaku, Toshihiko; Inagaki, Shuichiro; Hashimoto, Yutaka; Kimura, Kazuhiro; Miyamoto, Shinji; Hadama, Tetsuo; Ono, Katsushige.

In: Biochemical and Biophysical Research Communications, Vol. 345, No. 2, 30.06.2006, p. 766-773.

Research output: Contribution to journalArticle

Takebayashi, Satoshi ; Li, Yulong ; Kaku, Toshihiko ; Inagaki, Shuichiro ; Hashimoto, Yutaka ; Kimura, Kazuhiro ; Miyamoto, Shinji ; Hadama, Tetsuo ; Ono, Katsushige. / Remodeling excitation-contraction coupling of hypertrophied ventricular myocytes is dependent on T-type calcium channels expression. In: Biochemical and Biophysical Research Communications. 2006 ; Vol. 345, No. 2. pp. 766-773.
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