摘要
探讨内皮素对自发性高血压大鼠(SHR)和正常血压大鼠(WKY)离体灌注心脏的影响,发现其具有强烈持久的冠脉收缩作用,减慢心率和致心律失常效应,可直接增强但间接减弱心脏收缩力,并可损害心脏的舒张和收缩速率。与WKY组相比,SHR肥厚心脏的舒缩功能更为易损。卡托普利(巯甲丙脯酸)预处理可减弱内皮素的冠脉—心肌效应。
The functional impacts of endothelin (ET) on normal and hypertrophied hearts were studied on isolated, perfumed hearts of male 32-week-old spontaneously hypertensive rats (SHR) and agematched Wistar-Kyoto rats (WKY). Vehicle or single dose of ET (25,50 or 100 pmol/g wet weight of heart) was injected into the aorta and its effects on coronary flow(CF), amplitude of active contraction (A), rate of contraction and relaxation (±dA/dt), heart rate (HR)and rhythm were observed and its interaction with captopril were evaluated. ET caused dramatic and long-lasting fall of CF in all preparations, which was dosedependent and comparable in SHR and WKY(about 50% over baseline for 60—80 minutes at 25 pmol/g). ET induced minor, transient (25 pmol/g) or major, persistent (50 or ICO pmol/g) reduction of A without significant difference in both strains. ET depressed +dA/dt, with greater and longer depression in SHR. ET reduced HR and provoked ventricular arrhythmia. These effecta were attenuated by pretreatment with captopril (80 mg/L of perfusate). The study demonstrates that ET is a potent coronary vasoconstrictor with direct positive and indirect negative inotropic effects, and that hypertrophied hearts of SHR is more vulnerable to ET's myocardial-depressive effects, and indicates that ET may be a potential mediator in coronary vasospasm, and in dysfunction of hypertrophied hearts.
出处
《中国循环杂志》
CSCD
1992年第2期169-171,共3页
Chinese Circulation Journal
关键词
内皮素
心脏效应
心肌肥厚
Endothelin
Cardiac effects
Myocardial hypertrophy
