Effect of waterª²immersion restraint stresss on leptin expression in submandibular gland of rats

    ZHAO Yuª²Feng, LIU Guangª²Zhong, YANG Jiaª²Zhou, MIAO Naiª²Zhou

    Department of Histology and Embryology, Depentment of Nerue Internal Medical, Affiliated Hospital, Medical college of Yan¬ðan University, Yan¬ðan 716000, China

    ¡¾Abstract¡¿ AIM: To observe the changes of leptin expression in submandibular gland of rats following waterª²immersion restraint stress and to explore the effects and significance of stress response on leptin secretion in submandibular gland. METHODS: Twenty Spragueª²Dawley rats were divided into waterª²immersion 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 enzymeª²linked immunosorbent assay (ELISA). RESULTS£ºLeptin 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. ......