Altered Electrophysiological Properties of Coronary Artery in Isoprenaline-Induced Cardiac Hypertrophy

• 영문명: Altered Electrophysiological Properties of Coronary Artery in Isoprenaline-Induced Cardiac Hypertrophy
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Nari Kim Jin Han Euiyong Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제5권 제5호, 413~421쪽, 전체 9쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2001.01.01

영문 초록

An impaired smooth muscle cell (SMC) relaxation of coronary artery by alteration of K^⁢ channels would be the most potential explanation for reduced coronary reserve in left ventricular hypertrophy (LVH), however, this possibility has not been investigated. We performed morphometrical analysis of the coronary artery under electron microscopy and measured Ca^2⁢-activated K (K_Ca) currents and delayed rectifier K (K_dr) currents by whole-cell and inside-out patch-clamp technique in single coronary arterial SMCs from rabbits subjected to isoprenaline-induced cardiac hypertrophy. Coronary arterial SMCs underwent significant changes in ultrastructure. The unitary current amplitude and the open-state probability of K_Ca channel were significantly reduced in hypertrophy without open-time and closed-time kinetic. The concentration-response curve of K_Ca channel to Ca^2⁢ is shifted to the right in hypertrophy. The reduction in the mean single channel current and increase in the open channel noise of K_Ca channel by TEA were more sensitive in hypertrophy. K_dr current density is significantly reduced in hypertrophy without activation and inactivation kinetics. The sensitivity of K_dr current on 4-AP is significantly increased in hypertrophy. This is the first study to report evidence for alterations of K_Ca channels and K_dr channels in coronary SMCs with LVH. The findings may provide some insight into mechanism of the reduced coronary reserve in LVH.

키워드

Reduced coronary reserve LVH Coronary artery structure Ca^2⁢ -activated K^⁢ currents Delayed rectifier K^⁢ currents