高血压性心肌肥大逆转过程心肌胶原的变化

CHANGES OF MYOCARDIAL COLLAGEN DURING REGRESSION OF HYPERTENSIVE CARDIAC HYPERTROPHY IN RATS

目的 :探讨高血压性心肌肥大及逆转过程心肌间质胶原骨架网络超微结构的变化 ,为临床治疗提供理论依据。方法 :建立大鼠高血压模型 ,并于模型建立后 4周 ,用 30mg·kg- 1卡托普利每日给大鼠灌胃 ,连续 1 2周 ,以逆转心肌肥大。用多道生物信号分析系统记录血压和心率 ,用透射电子显微镜观察心肌间质胶原骨架网络的超微结构。结果 :逆转前 (模型建立后 4周 )及逆转期第 4、8周高血压组的收缩压 (SBP)、舒张压 (DBP)、平均动脉压 (MAP)比两对照组高 ,第1 2周差别不明显 ,假手术和正常对照组之间的差别无统计学意义。逆转前 ,心肌间质胶原骨架网络病变严重 ,主要表现在胶原纤维骨架网络区蛋白质沉积 ;在逆转期的第 4周、8周、1 2周 ,蛋白质的沉积逐渐减少 ;第 1 2周间质胶原骨架网络病变各处不甚一致 ,有的区域接近正常。结论 :高血压性心肌肥大间质胶原骨架网络区的病变是主要损伤之一 ;开搏通能部分逆转心肌肥大对间质胶原骨架网络的作用 。

Objective:To investigate the changes in ultramicro-structure of myocardial collagen network during regression of hypertensive cardiac hypertrophy,so as to provide theoretical basis for clinical therapy.Methods: Hypertensive model in rats was established, and regression of cardiac hypertrophy was induced by daily intake of captopril(30 mg·kg -1 )4 weeks later for 12 weeks.BP and HR were recorded with polygraph channel system,and ultramicro-structure of myocardial collagen network were observed by transmission electromicroscopy.Results:(1)Systolic blood pressure,diastolic blood pressure and mean arterial pressure in hypertension group were higher than those in control groups(shammed operation control and normal control)before and 4, 8 weeks after regression,and were not significantly different from those in controls 12 weeks later.(2)Severe pathological changes in myocardio-interstitial collagen matrix network including sedimentation of protein in network were found before regression, and gradually diminished after regression. The changs were not uniform, somewhere became nearly normal 12 weeks later.Conclusions: Sedimentation of protein in collagen matrix network is one of the pathological changes in hypertensive cardiac hypertrophy. The effect of captopril on hypertensive cardiac hypertrophy is mainly to reduce protein sediment in collagen network.