Objective: To observe the incidence of spontaneous lesions in SD rats of different ages and genders in different environments, and to provide pathological background information for drug safety research.
Method: Blank control SD rats were used in our safety assessment test, and they were all used as female posts. Reproduce in the barrier system and normal environment. They were slaughtered and dissected at 19, 23, 32, and 36 weeks of age, and pathological sections were prepared regularly. The pathological changes of main tissues and organs were observed under an optical microscope, and the incidence of natural disease types of animals was calculated. Comparing the results with the barrier system, the incidence of natural damage in the respiratory system of rats under normal conditions is significantly higher. In addition, under barrier and normal eating conditions, the incidence of spontaneous lesions in SD rats increases with age; at the same time, a small number of lesions show obvious gender differences, of which progressive cardiomyopathy kidney mineral deposits are the most obvious. Histopathological examination revealed progressive cardiomyopathy, liver localized inflammatory cell infiltration, hepatocyte follicular degeneration, spontaneous hepatocyte foci, localized lung inflammatory cell infiltration, foam cell accumulation in alveolar cells, renal calcification, kidney Interstitial inflammatory cell infiltration, pancreatic atrophy, tracheitis cell infiltration, prostatic interstitial inflammation, testicular tubule atrophy, tubule small epithelial cell shedding, endometritis and vaginal inflammation are the main natural phenomena. This is a disease.
Conclusion: The various types and incidences of natural damage in SPF SD rats reported in this article have enriched the background data of experimental animals and provided references for relevant technicians.