糖尿病大鼠颌下腺肥大细胞数量及转化生长因子β1的表达

Number of mast cells and expression of transforming growth factor beta 1 in the submandibular gland of diabetes mellitus rats

背景:研究表明,持续高血糖可导致大鼠颌下腺的细胞出现退行性改变,表现为细胞因子表达增加,糖原代谢改变,分泌功能减弱。关于肥大细胞及转化生长因子β1与糖尿病颌下腺组织病变的关系研究较少。目的:观察糖尿病状态下颌下腺组织中肥大细胞数量与形态变化和转化生长因子β1的表达。方法:雄性SD大鼠32只,随机分为实验组和对照组,实验组注射四氧嘧啶成模后的4,8,12周测量体质量和血糖,并与对照组大鼠一同取下颌下腺组织做苏木精-伊红染色和甲苯胺蓝染色观察并计数肥大细胞,SP免疫组织化学染色方法检测转化生长因子β1棕黄色阳性细胞数量。结果与结论:①肥大细胞在正常鼠及糖尿病鼠颌下腺组织中均有表达,实验组与对照组比较肥大细胞数随病程延长而增多,实验组不同时期明显多于对照组(P<0.01)。②转化生长因子β1阳性细胞数在正常大鼠及糖尿病大鼠颌下腺的腺泡细胞、颗粒曲管及纹状管细胞中均有表达,阳性颗粒位于胞浆内,糖尿病时,随病程延长而增多,实验组不同时期明显多于对照组(P<0.01)。结果可见糖尿病大鼠颌下腺中肥大细胞与转化生长因子β1表达增强与糖尿病病程呈正相关。

BACKGROUND： Continuous hyperglycemia may result in degenerative changes in submandibular gland cells, showing the increased cytokine expression, altered glycogen metabolism and attenuated secretion function. Little evidence is available addressing the mast cells and transforming growth factor beta 1 in diabetic submandibular gland lesions. OBJECTIVE： To observe the number and morphological changes of mast cells, as well as transforminggrowth factor beta 1 expression in the submandibular gland of diabetic rats. METHODS： Thirty-two male Sprague-Dawley rats were randomly divided into an experimental group and a control group. The body weight and blood glucoselevels of all rats were measured at 4, 8, and 12 weeks after alloxan injection was given in the experimental group. Submandibular gland tissues were harvested for hematoxylin-eosin staining and toluidine blue staining to count mast cells. Transforming growth factor beta 1- positive cells were measured using SP immunohistochemical staining method. RESULTS AND CONCLUSION： （1） Mast cells were expressed in submandibular gland of both normal rats and diabetic rats, and the number of mast cells gradually increased as the disease duration prolonged and was significantly higher in the experimental group than in the control group （P 〈 0.01）. （2） The transforming growth factor beta 1-positive cells were expressed in submandibular gland acinar cells, granular convoluted tubule and striated duct cells in both normal rats and diabetic rats, and the positive granules were localized in the cytoplasm. The number of positive cells gradually increased along with the duration of diabetes and was significantly higher in the experimental group than in the control group （P 〈 0.01）. The mast cells and upregulated expression of transforming growth factor beta 1 in the submandibular gland of diabetic rats are positively related to the duration of diabetes mellitus.