【Animal Modeling】-Pathological Study of Spontaneous Lesion in SD Rats of Different Ages, Genders and Environments

  Objective To observe the incidence of spontaneous lesions in SD rats of different environments, ages and genders, and to provide background data for pathological evaluation of drug safety research.

  Methods The SD rats in the blank control group in the safety assessment test of our center were used for both females, and they were raised in a barrier system and a normal environment, respectively. They were sacrificed at 19, 23, 32, and 36 weeks of age for autopsy, and pathological sections were routinely made. , Observe the pathological changes of the main tissues and organs under the light microscope, and count the types and incidence of spontaneous lesions in animals.

  Results Compared with the barrier system, the incidence of spontaneous lesions in the respiratory system of rats in the normal environment was significantly higher; in addition, the incidence of spontaneous lesions in SD rats increased with the increase of age in both the barrier environment and the normal environment. At the same time, a small number of lesions showed obvious gender differences, among which progressive cardiomyopathy and renal mineralization were the most obvious. Histopathological examination showed progressive cardiomyopathy, focal inflammatory cell infiltration in the liver, vacuolar degeneration of hepatocytes, spontaneous variant hepatocyte foci, focal inflammatory cell infiltration in the lung, accumulation of foam cells in the alveoli, renal mineralization, renal interstitium Inflammatory cell infiltration, pancreatic atrophy, bronchitis cell infiltration, prostatic interstitial inflammation, testicular seminiferous tubule atrophy, seminiferous tubule epithelial cell shedding, endometrial inflammation and vaginal inflammation are the main spontaneous lesions.

  Conclusions The types and incidences of various spontaneous lesions in SPF SD rats reported in this paper enrich the background data of experimental animals and can provide reference for relevant technicians.