急性冷胁迫对中华鳖幼鳖肠道黏膜组织的影响

为了探究急性冷胁迫对中华鳖(Pelodiscus sinensis)幼鳖肠道不同区段黏膜组织学特征的影响, 实验检测了急性冷胁迫前后血清二胺氧化酶(Diamine oxidase, DAO)的活性, 同时观察了急性冷胁迫前后中华鳖肠道黏膜的相关组织形态的差异。DAO活性显示: (1)在第一次急性冷胁迫实验中, 中华鳖血清DAO活性随急性冷胁迫时间的增加而呈现降低趋势, 并在冷胁迫到达48h降到了最低水平; (2)在急性冷胁迫及复温实验中, 中华鳖血清DAO的活性, 在冷胁迫3d后显著降低, 但随着温度的恢复, DAO活性又恢复到正常水平。组织病理结果显示: (1)急性冷胁迫对中华鳖肠道(回肠后段和大肠)黏膜上皮的形态没有明显影响; (2)急性冷胁迫对回肠后段的杯状细胞数目、肠绒毛长度和绒毛长度/隐窝深度的比值没有显著影响, 但会使回肠后段黏膜厚度显著降低; (3)急性冷胁迫会使大肠的杯状细胞数目降低。这表明急性冷胁迫会改变中华鳖肠道黏膜的结构, 但在不同的肠段, 这种改变是不同的。回肠后段和大肠在同样的冷胁迫方式下黏膜机械屏障的不同变化情况, 提示中华鳖肠道各段对急性冷胁迫具有特殊的应对方式。

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.