F344大鼠4种饮用水饲养2年实验病理学观察

Pathological observation of F344 rats drinking four different types of water for two years

目的观察F344大鼠在自然生存状态下常年饮用天然矿泉水、自来水、纯净水和矿物质水等4种饮用水对其生存寿命、疾病发生率、死亡率等指标的影响,为GLP条件下动物饲养用水选择和动物自发病变的研究提供背景数据。方法 SPF级8周龄F344大鼠336只,雌雄各半,随机分为4组,分别饮用天然矿泉水、自来水、纯净水和矿物质水4种饮用水,每组84只动物。实验开始后第6个月、12个月、18个月和24个月每组分别活杀8、16、16和44只动物,称重动物心脏、肺脏、肝脏、脾脏、肾脏、胸腺、肾上腺、睾丸(或卵巢)、附睾(或子宫)和脑等脏器并计算脏器系数,常规病理学取材、制片后显微镜检查,比较各组动物在4个时间点发生病变的类型和发病率。结果各组动物发病以F344大鼠常见的自发性病变为主,包括非增殖性病变和增殖性病变。主要的非增殖性病变包括心脏乳头肌纤维化,肺细支气管旁慢性炎症,肾脏肾小管扩张、蛋白管型、肾小管萎缩和钙沉积等,生殖器官退行性改变等;高发的肿瘤性病变主要包括睾丸间质细胞瘤、垂体腺瘤、单核细胞白血病、皮下纤维瘤、乳腺纤维腺瘤、嗜铬细胞瘤等。各组动物上述病变类型及发病率、生存时间、死亡率等指标比较均未见明显差异。结论天然矿泉水、自来水、纯净水和矿物质水等4种饮用水对F344大鼠生存时间、死亡率、自发病变类型与发生率没有影响。本研究为了解不同饮用水对实验动物的影响提供了参考,丰富了F344大鼠自发病变的病理学数据积累。

Objective To investigate the possible effects of four different types of drinking water on the type and incidence of spontaneous lesions＇ and mortality rates among F344 rats during a period of two years. Methods Three hundred and thirty-six the F344 rats at the SPF level, with males and females in half and at the age of eight weeks, were randomly divided into four groups：natural mineral water group, tap water, purified water group and mineral water group, respectively. Eight, sixteen, sixteen and forty-four rats in each group were sacrificed at 6, 12, 18 and 24 months after the start of the study. The mass of the heart, lung, liver, spleen, kidney, adrenal gland, thymus, brain, testes （ovaries for the female） and epididymis （uterus for the female） were recorded and the coefficients of the organs were calculated. Histopathological examination was conducted. The type and incidence of spontaneous lesions in each group were recorded and calculated. Results The type and incidence of spontaneous lesions, including non-neoplastic lesions and neoplastic lesions in each group, were compared. Non-proliferative lesions included murine progressive cardiomyopathy, lung bronchus-associated lymphoid tissue （BALT）, enlargement or atrophy of tubules, proteinaceous cast and calcification in the kidney, and genital tissue degeneration. The frequently found neoplastic lesions were Leydig cell tumor, adenoma in pituitary gland, large granular lymphoma （LGL）, subcutaneous fibroma, mammary adenoma and pheoehromocytoma. No statistically significant was found between the four groups with regard to the type and incidence of lesions and mortality rates. Conclusion This study enriches the pathological data of the F344 rats and throwes light on the selection of appropriate drinking water for animals in GLP laboratories.