THE DIFFERENT RESPONSE OF THE INTESTINAL MUCOSAL HISTOLOGICAL FEATURES IN DIFFERENT SECTIONS OF JUVENILE CHINESE SOFT-SHELLED TURTLE UNDER ACUTE COLD STRESS

To investigate the effects of acute cold stress on the mucosal histology in different sections of the juvenile Pelodiscus sinensis, the activity of serum diamine oxidase (DAO) and histological features of intestinal mucosa in Chinese soft-shelled turtle in culture temperature and acute cold stress were conducted. The first acute cold stress reduced the DAO activity with the lowest level at 48h after cold stress. In the acute cold stress and rewarming experiment, the DAO activity decreased significantly after 3 days of cold stress and then restored to normal level with the recovery of temperature. Histopathological results showed no significant difference in the morphology of mucosal epithelium in the intestine (posterior segment of ileum and large intestine) between acute cold stress group and control group. There were no significant difference in the number of goblet cells, the length of villus and the ratio of villus length to crypt depth in the posterior segment of ileum between acute cold stress group and control group, while the mucosal thickness in the posterior segment of ileum significantly decreased in the acute cold stress group in comparison to control group. Acute cold stress significantly reduced the large intestine number of goblet cells. The structures of the intestinal mucosal mechanical barrier of Chinese soft-shelled turtle under acute cold stress are an intestinal segment dependent pattern. These results suggest that the various segments of the intestine of Chinese soft-shelled turtle have a special response style to acute cold stress.