实验动物呼吸系统主要器官比较组织学研究

Comparative study of the histology of respiratory organs in six laboratory animal species

目的比较实验动物呼吸系统主要器官的组织学特征,为制定实验动物病理检测标准、以及毒理学、新药安全性评价提供依据。方法选取实验动物质量国家检测标准检测合格的恒河猴30只、昆明小鼠20只、SD大鼠20只、日本大耳白兔18只、比格犬16只、树鼩20只。除昆明小鼠采用颈椎脱臼致死外,其余动物麻醉后放血处死和病理解剖,对气管、肺脏进行病理大体检查和取材,常规病理制片,进行HE染色、特殊染色和免疫组化染色,显微镜下观察气管、肺脏的组织结构和细胞结构异同。结果 (1)实验动物气管上皮杯状细胞有差异:恒河猴、比格犬、日本大耳白兔杯状细胞较多,大鼠、小鼠、树鼩则较少或无。上皮分泌的黏液类型以中性黏液为主,比格犬杯状细胞分泌的黏液类型有中性黏液和酸性黏液。(2)实验动物黏膜下腺泡分布有差异:比格犬黏膜下层的腺泡最多,恒河猴、大鼠、小鼠、树鼩腺泡数量偏少,日本大耳白兔黏膜下层的混合腺泡最少。(3)实验动物的肺内支气管分支有差异:比格犬、恒河猴、日本大耳白兔由叶支气管、段支气管、小支气管、细支气管、终末细支气管和呼吸性细支气管组成,树鼩、大鼠、小鼠只由细支气管、终末细支气管和呼吸性细支气管组成。(4)实验动物细支气管组织结构有差异:恒河猴、比格犬的细支气管平滑肌为完整环形平滑肌层,没有缺失,而大鼠、小鼠、树鼩及日本大耳白兔的细支气管平滑肌薄或缺失。恒河猴、树鼩、大鼠细支气管有少量杯状细胞,其余实验动物均无杯状细胞。(5)实验动物Clara细胞形态有差异:比格犬Clara细胞呈立方形,其余动物呈柱状。结论实验动物呼吸系统组织结构的质是相同的,差异在于量的不同。研究人员在制定病理学检测标准、实验研究、药物安全性评价时应予充分考虑。

Objective To obtain histological data of the respiratory organs of laboratory animals and provide standard reference data for pathological inspection, toxicological studies and drug safety evaluation. Methods Thirty ordinary adult rhesus monkeys, 20 KM mice, 20 SD rats, 18 Japanese white rabbits, 16 Beagle dogs, and 20 Tupaia belangeri were included in this study. After intravenous anesthesia, the animals were sacrificed by femoral artery bleeding,and the trachea and lungs were removed, fixed in 10% formalin, and paraffin sections were stained with HE. The histological structure of the trachea and lungs was observed by light microscopy. The similarities and differences of the trachea and lung structures were compared among the different animal species. Results （ 1 ） The goblet ceUs in the tracheal epithelium： There were more goblet cells in the Beagle dogs and Japanese white rabbits than in the SD rats, KM mice and Tupaia belangeri, and their secretion was mainly neutral mucus in most animal species, but neutral and acidic mucus in Beagle dogs. （2） Distribution of submucosal glandular acini： There were most numerous submucosal glandular acini in the Beagle dogs, less numerous in the rhesus monkeys, SD rats, KM mice, and Tupaia belangeri, and least acini of submucosal mixed glands in the Japanese white rabbits. （ 3 ） The bronchial branches ： The bronchial tree in the Beagle dogs, rhesus monkeys and Japanese white rabbits was composed of lobar bronchi, segmental bronchi, small bronchi, bronchioles, terminal bronchioles and respiratory bronchioles. In the SD rats, KM mice and Tupaia belangeri, it was composed of only bronchioles, terminal bronchioles and respiratory bronchioles. （4） Histological structure of bronchioles： The bronchioles of Beagle dogs and rhesus monkeys had an intact circular smooth muscle layer, which was a thin circular layer or lack of it in the SD rats, KM mice, Tupaia belangeri and Japanese white rabbits. There was a small amount of goblet cells in the bronchioles of rhesus monkey, Tupaia belangeri and SD rats, but absent in the other three species. （5） Morphology of Clara cells in the bronchioles： There were cuboidal Clara cells in the Beagle dogs, but columnal Clara cells in the other species. Conclusions There are some histological differences in the trachea and lungs of laboratory animals, which should be fully considered in drawing up the standard of pathologic examination, experimental research, or drug safety evaluation.