Altered Delayed Rectifier K⁢ Current of Rabbit Coronary Arterial Myocytes in Isoproterenol-Induced Hypertrophy

• 영문명: Altered Delayed Rectifier K^⁢ Current of Rabbit Coronary Arterial Myocytes in Isoproterenol-Induced Hypertrophy
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Nari Kim Jin Han Euiyong Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제5권 제1호, 33~40쪽, 전체 8쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2001.01.01

영문 초록

The aim of present study was to define the cellular mechanisms underlying changes in delayed rectifier K^⁢ (K_DR) channel function in isoproterenol-induced hypertrophy. It has been proposed that K_DR channels play a role in regulation of vascular tone by limiting membrane depolarization in arterial smooth muscle cells. The alterations of the properties of coronary K_DR channels have not been studied as a possible mechanism for impaired coronary reserve in cardiac hypertrophy. The present study was carried out to compare the properties of coronary K_DR channels in normal and hypertrophied hearts. These channels were measured from rabbit coronary smooth muscle cells using a patch clamp technique. The main findings of the study are as follows: (1) the K_DR current density was decreased without changes of the channel kinetics in isoproterenol-induced hypertrophy; (2) the sensitivity of coronary K_DR channels to 4-AP was increased in isoproterenol-induced hypertrophy. From the above results, we suggest for the first time that the alteration of K_DR channels may limit vasodilating responses to several stimuli and may be involved in impaired coronary reserve in isoproterenol-induced hypertrophy.

키워드

Potassium channels Isoproterenol Hypertrophy Coronary Patch clamp technic