热应激条件下猪肠道糖皮质激素受体的表达变化

Glucocorticoid receptor expression changes in porcine intestinal gut under heat stress conditions

为探究糖皮质激素受体(GR)在热应激引发猪肠道病变中的作用,本研究将48头2月龄左右的健康猪(15±2 kg)随机分为两组(实验组和对照组),实验组饲养于环境温度为35±1℃的人工气候温室,对照组环境温度为28±3℃,相对湿度均为75%~80%。在热应激的第1 d、7 d、14 d和21 d迫杀受试猪,采集其肠道组织,采用免疫组织化学法和western blot分别检测了GR在不同肠道组织的分布及表达情况。免疫组织化学结果显示,热应激第7 d和第14 d实验组猪十二指肠粘膜层GR表达量显著增高;盲肠和结肠GR表达量在热应激第14 d上调。Western blot结果显示,实验组猪十二指肠和结肠中GR表达量随应激时间延长而增加,在热应激第14 d达到峰值。而盲肠GR表达量较对照组显著下调(p<0.05)。本实验表明热应激影响猪肠道GR的表达水平,为进一步阐述GR在热应激诱发猪炎性肠病的作用提供实验依据。

In order to explore the mechanisms of glucocorticiod receptor(GC) inducing pathological changes in porcine intestine under heat stress conditions, 48 healthy pigs(15 ±2 kg) around 2 months old were randomly divided into two groups(experimental group and control group). The experimental group was raised in an artificial climate greenhouse at an ambient temperature of 35±1℃. The environmental temperature of control group was 28±3℃, and the relative humidity range was 75% to80%. All the experimental pigs were killed on the 1 st, 7 th, 14 th and 21 st day after treatment, and the intestinal tissues were collected. The distribution and expression of GR in different intestinal tissues were detected by immunohistochemistry and western blot. The results of immunohistochemistry showed that the expression of GR in the duodenum mucosa of the experimental pigs was significantly increased on the 7 th and 14 th day under heat stress condition in comparison with control group and on the 14 th day of treatment, the expression of GR in the cecum and colon of those pigs was up-regulated. Furthermore, western blot results showed that the expression of GR in the duodenum and colon of the experimental group increased with the prolongation of stress time reaching the peak on the 14 th day and the expression of GR in cecum was significantly down-regulated compared with the control group(p<0.05). Our study provides evidence that the expression level of GR in pig intestinal tissue was affected by heat stress, which provides a reference for further revealing the molecular mechanisms of heat stress induced porcine inflammatory bowel disease.