糖尿病大鼠下颌下腺内AQP2和AQP4表达的变化及意义

Changes of the expression of AQP2 and AQP4 in the submandibular glands of diabetic rats and itssignificance

目的通过观察AQP2和AQP4在糖尿病大鼠下颌下腺内的表达变化,探究糖尿病患者口渴的可能机制。方法24只SD大鼠分为对照组、糖尿病组和治疗组三组,每组各8只。糖尿病组和治疗组复制糖尿病模型,同时,治疗组给予胰岛素治疗。造模3个月后处死各组大鼠并取下颌下腺组织,利用免疫组化染色、免疫印迹及实时荧光定量PCR检测其内AQP2和AQP4表达情况。结果免疫组织化学显示AQP2和AQP4免疫阳性反应物主要沉积于大鼠下颌下腺纹状管上皮细胞胞质内,对照组呈棕黄色,糖尿病组呈浅黄色;免疫印迹及实时荧光定量PCR检测显示糖尿病大鼠下颌下腺内AQP2和AQP4蛋白与mRNA表达明显下降。结论下颌下腺内AQP2和AQP4表达下降,可能是导致糖尿病患者口渴多饮的原因之一。

Objective To explore the possible mechanism of thirst for patients with diabetes mellitus by observing the expression of AQP2 and AQP4 in submandibular gland of rats with diabetes mellitus.Methods Twenty four SD rats were divided into control group,diabetes mellitus group and treatment group.Diabetic group and treatment group were used to duplicate diabetes mellitus model.Meanwhile,the treatment group was given insulin for treatment.After 3 months of modeling,the rats in each group were sacrificed and the submandibular gland tissues were isolated.The expression of AQP2 and AQP4 were detected by immunohistochemistry,western blot and real-time fluorescent quantitative PCR.Results Immunohistochemistry results showed that AQP2 and AQP4 immunoreactive products were mainly deposited in the cytoplasm of striated duct epithelial cells in submandibular gland of rats,and the control group presented brownish yellow,and the diabetes mellitus group was presented light yellow.Western blot and real-time fluorescent quantitative PCR showed that the expression of AQP2 and AQP4 protein and mRNA in submandibular gland of rats with diabetes mellitus was significantly reduced.Conclusions The decrease of AQP2 and AQP4 expression in submandibular gland may be one of the causes of thirst and excessive drinking for patients with diabetes mellitus.