Wistar大鼠心脏自发性病变的病理学观察

目的 了解Wistar大鼠心脏自发性病变发病情况,为长期致癌性研究、老年病学研究及毒性病理学提供背景资料.方法 采用160只清洁级Wistar大鼠,雌雄各半,常规饲养,分别在9月龄、12月龄、18月龄、24月龄时处死40只大鼠,HE及Masson三色法染色,观察心脏的病理改变.结果 9月龄Wistar大鼠心脏未见明显病理改变；12月龄Wistar大鼠月龄心脏病变的发病率为2.5％ (1/40),表现为少数心肌细胞变性坏死伴少量以单核细胞为主的炎细胞浸润；18月龄大鼠心脏病变的发病率为57.5％(23/40),表现为轻至中度心肌病,雄性发病率高于雌性.24月龄大鼠100％ (40/40)出现不同程度的心肌病,并有2.5％ (1/40)发生心内膜下纤维组织增生.Masson染色显示9月龄大鼠心脏血管周围及心脏瓣膜环下有少量胶原纤维,随年龄增长,血管周围及心脏瓣膜环下胶原纤维逐渐增多,并延伸入心肌细胞间.结论 随年龄增长,大鼠心脏自发病变比率升高,主要病变为心肌病,偶尔可发生心内膜下纤维组织增生；胶原纤维沉积首先发生于血管周围及心脏瓣膜环下,随年龄增长而增多,可能与大鼠心肌病的的发生密切相关.

Pathological Observation of Spontaneous Heart Lesions in Wistar Rats

Objective This study was aimed to learn spontaneous lesions in the heart of Wistar rats.Methods A total of 160 male and female matched Wistar rats were studied.Forty rats were sacrificed at 9,12,18,24 months of age,respectively.Histopathological changes of the heart were observed and analyzed.Results No obvious pathological changes were detected in 9-month old Wistar rats.Mild pathological changes as small foci of necrosis and degeneration were found in the heart in 2.5%(1/40) of the 12-month old rats.The incidence of cardiomyopathy was 57.5%(23/40)and 100%(40/40)in 18-and 24-month old rats,respectively,and there was subendocardial fibrosis in 2.5%(1/40) of the 24-month old rats.The Masson staining showed that mild collagen fibrosis developed firstly at perivascular area and under valve annulus in a few of 9-month old rats,and increased with increasing age.Conclusions Wistar rat can develop heart disease spontaneously.The incidence rises up with increasing age,mainly cardiomyopathy and occasionally subendocardial fibrosis.Collagen fiber deposition may be closely related to the genesis of rat cardiomyopathy.