水浸束缚应激对大鼠下颌下腺内瘦素表达的影响

目的:观察应激状态下大鼠颌下腺内瘦素表达的变化,探讨应激反应对颌下腺瘦素分泌的影响及其意义.方法:采用水浸束缚应激(WRS)方法,将20只SD大鼠随机均分为WRS组(n=10)和对照组(n=10),用免疫组织化学方法观察大鼠颌下腺内瘦素的定位与分布;用ELISA法检测两组大鼠血清和颌下腺组织中瘦素水平.结果:瘦素免疫反应阳性细胞主要定位于颌下腺导管的颗粒曲管和纹状管,腺泡细胞为阴性,其中颗粒曲管上皮细胞呈强阳性反应. WRS组大鼠颌下腺导管上皮细胞瘦素免疫反应细胞的染色强度高于对照组. 与对照组相比,WRS组大鼠血清和颌下腺中瘦素水平均显著升高(P＜0.01).结论:瘦素表达于大鼠颌下腺导管上皮细胞;水浸束缚应激可致大鼠血清和颌下腺中瘦素浓度增加,颌下腺内瘦素可能参与应激反应过程的调节.

Effect of water-immersion restraint stresss on leptin expression in submandibular gland of rats

AIM: To observe the changes of leptin expression in submandibular gland of rats following water-immersion restraint stress and to explore the effects and significance of stress response on leptin secretion in submandibular gland. METHODS: Twenty Sprague-Dawley rats were divided into water-immersion restraint stress (WRS) group (n=10) and normal control group (n=10). Localization and distribution of leptin in rat submandibular gland were observed by immunohistochemistry, and the concentrations of leptin in serum and submandibular gland were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS:Leptin immunoreactive cells were mainly located in the epithelial cells of the granular convoluted and striated ducts.The immunocomplexes were distributed in the epithelial cytoplasm of the ducts but not in the nuclei. The staining intensity for leptin in the granular convoluted duct was much higher than that in striated duct. The leptin staining in the ducts of submandibular gland in WRS group was denser than that in normal control group. The concentrations of leptin in both serum and submandibular gland were increased markedly compared with that in normal control group (P<0.01). CONCLUSION: Leptin is widely expressed in the epithelial cells of the granular convoluted and striated ducts of the rat submandibular gland. WRS can lead to the enhanced expression of leptin in rat submandibular gland, and these results suggested that leptin in submandibular gland might be involved in the regulation of stress response process.