糖尿病大鼠下颌下腺内nNOS和NT-3表达变化及意义

Expression of nNOS and NT-3 in the submandibular gland of diabetic rats and its significance

目的观察不同病程糖尿病大鼠下颌下腺内神经元型一氧化氮合酶(nN OS)和神经营养因子-3(NT-3)的表达变化,探讨其对糖尿病下颌下腺结构和功能的影响。方法 48只SD大鼠随机分为对照组、糖尿病组和治疗组。糖尿病组和治疗组给予腹腔注射链脲佐菌素复制2型糖尿病模型,治疗组给予胰岛素治疗,于造模后3个月和6个月每组分别处死8只大鼠,测定空腹血糖,并取下颌下腺组织,分别进行HE染色、免疫组织化学染色和计算机图像分析。结果糖尿病组血糖较同期对照组升高且随着病程的延长显著,治疗组血糖较同期糖尿病组下降。光镜下,与对照组相比,糖尿病组下颌下腺腺泡萎缩加重,颗粒曲管数目减少,管腔变窄,治疗组无明显变化;免疫组织化学法检测显示,nNOS在糖尿病组表达较同期对照组增强,在造模3个月表达最强,治疗组表达较同期糖尿病组降低;NT-3在糖尿病组表达较同期对照组降低且随病程的延长减少,治疗组较同期糖尿病组增强。结论糖尿病大鼠下颌下腺内nNOS表达升高和NT-3表达下降,可能是引起糖尿病下颌下腺结构和功能紊乱的重要原因;胰岛素治疗可能与nNOS和NT-3的表达改变有关。

Objective To observe the expression changes of neuronal nitric oxide synthase （nNOS） and neurotro- phin-3 （ NT-3 ） in the submandibular glands of the diabetes rats in the different courses of disease and to explore the influences of diabetes on the structures and functions of submandibular glands of diabetes rats. Methods 48 SD rats were randomly divided into control group, diabetes group and treatment group. Diabetes group and treatment group were injected with Streptozotocin to establish type 2 diabets model and treatment group were given insulin treatment. Three months and six months after modeling,8 rats in each group were sacrificed for assaying blood glu- cose, and the submandibular gland tissues were removed and subjected to HE staining, immunohistochemical stai- ning and computer image analysis. Results The blood glucose of diabetes group was higher than the control group at the same period and much higher than the control group as the course of disease extends. The blood glucose of treatment group was lower than the diabetes group at the same period. Under the light microscope, compared with the control group, the acinus of submandibular gland of diabetes group were aggravated, its granular convoluted tu- bereduced, its lumen narrows and the treatment group didn＇ t have obvious differences. Immunohistochemistry shows that the expression of nNOS in diabetes group was stronger than that in the control group at the same period and peaks three months after molding and the expression of nNOS in treatment group was lower than that in the dia- betes group at the same period; the expression of NT-3 in diabetes group was lower than that in the control group at the same period and decreased with the extension of course of disease and the expression of NT-3 in treatment group was stronger than that in the diabetes group at the same period. Conclusion Increased expression of nNOS and de- creased expression of NT-3 in the submandibular gland of diabetic rats may be an important cause of the structure and dysfunction of the submandibular gland in diabetes mellitus rats. Insulin therapy may be related to the changes of nNOS and NT-3.