大鼠左心室内膜超微结构年龄特征

Ultrastructure characteristics of left ventricle endocardium of rats in different age

目的探讨大鼠左心室内膜超微结构随年龄变化规律。方法取新生(9日龄)、青年(3月龄)、中年(11月龄)和老年(23月龄)Sprague-Dawley大鼠的左心室内膜组织,体积分数4%戊二醛磷酸缓冲液固定,制作透射电子显微镜(TEM)和扫描电子显微镜(SEM)样品,TEM下观察内皮细胞及内皮下胶原超微结构,SEM观察心肌内皮超微结构。结果随大鼠年龄增长,内皮细胞质膜变得薄而疏松,质膜小泡及突起逐渐减少;内皮下胶原从幼年到中年逐渐增多,排列方向一致;老年大鼠的胶原束排列紊乱松散,大鼠内皮细胞表面皱折增多,细胞核形态变长且排列趋于一致。结论随着年龄的增长,大鼠心内膜组织的超微结构发生明显变化,这与心脏功能的改变以及心脏疾病的发生相关。

Objective To investigate the change regularity of ultrastructure of left ventricle endocardium in rats of different age. Methods The Sprague-Dawley rats were divided into neonatal rats（9 days）,young rats（3 months）,middle-aged rats（11 months） and old rats（23 months） according to their age. The endocardium of the rats were fixed by 4% glutaral phosphate buffer and made samples for transmission electron microscope（ TEM） and scanning electron microscope（ SEM）. The endotheliocyte and subendothelial collagen were observed by TEM and the myocardial endothelial ultrastructure was observed by SEM. Results The plasma membrane of endocardium endothelial cell became thin and loose with aging,and the vesicles and protuberances reduced gradually. The number of subendothelial collagen increased gradually from neonatal to middle aged,and appeared uniform arrangement direction. However,the collagen arrangement in old rats became disorder and loose,the wrinkle on the surface of endotheliocyte increased,longer and uniform arrangement nucleus were viewed. Conclusion The ultrastructure of endocardium in rats vary significantly with aging,which may be associated with the change of cardiac function and the happening of myocardial disease.