17-β-雌二醇抑制去卵巢胰岛素抵抗大鼠血管重构的发生

Inhibiting Effect of 17-β-Estradiol on the Vascular Remodeling in Ovariectomized Rats with Insulin Resistance Induced by Fructose

目的观察17-β-雌二醇对高果糖诱导的去卵巢胰岛素抵抗大鼠血管重构的影响。方法将48只成年雌性SD(Sprague-Daw ley)大鼠随机分为正常对照组、模型组、17-β-雌二醇替代组、溶媒对照组,每组12只。正常对照组大鼠普通饲料喂养8周;模型组大鼠卵巢切除后,高果糖饲料喂养8周诱导胰岛素抵抗的产生;17-β-雌二醇替代组大鼠卵巢切除后,高果糖饲料喂养同时给予17-β-雌二醇(30μg/kg体重)每天皮下注射;溶煤对照组大鼠卵巢切除后高果糖饲料喂养8周,同时每天给予30μL/kg体重的无水乙醇皮下注射。实验8周末检测各组大鼠收缩压、血清雌二醇,空腹血糖和血清胰岛素水平,计算胰岛素敏感指数。大鼠放血处死后甲醛固定主动脉和肠系膜小动脉,石蜡包埋,切片,HE染色,病理图像分析系统测量主动脉和肠系膜小动脉重构的指标:内径、中膜、中膜/内径、中膜横截面积。结果与正常对照组相比,模型组大鼠收缩压、空腹血糖和血清胰岛素显著性升高,胰岛素敏感指数显著性降低,肠系膜小动脉内径减小,中膜和中膜/内径比值增加,而主动脉未见明显改变;17-β-雌二醇替代逆转上述改变。结论17-β-雌二醇能抑制高果糖诱导的去卵巢大鼠胰岛素抵抗和肠系膜小动脉重构的产生。

Objective To investigate the inhibiting effect of 17-β-estradiol on the vascular remodeling in ovariectomized rats with insulin resistance induced by high fructose. Methods Forty eight mature female Sprague - Dawley （ SD ） rats were randomly divided into four groups ： the normal control group （ n = 12 ） fed with the normal diet for eight weeks ; the model group ）（ n = 12 ） ovariectomized and fed with the high fructose diet for eight weeks ; the 17 -β- estradiol replacement group （ 17-β- E2, n = 12） ovariectomized and fed with the high fructose diet for eight weeks, and meanwhile injected with the physiological - dose 17-β- E2 （ 30 μ/kg · d ） subcutaneously every day ; the vehicle control group （ VC. n = 12 ） ovariectomized and fed with the high fructose diet for eight weeks, meanwhile injected with the equivalent alcohol subcutaneously every day. Systolic blood pressure （ SBP ）, fasting blood sugar （FBS） and fasting serum insulin （FSI） and insulin sensitivity index （ISI） were measured. Thoracic artery and mesenteric artery were fixed in formalin, sliced and HE dyed. Pathology analysis system was used to measure the remodeling index of aorta and mesenteric artery： Lumen, media, media/lumen, media cross -sectionarea. Results Compared with the normal control group, SBP, FBS and FSI were increased significantly and ISI was decreased significantly in the model group. The lumen diameter of mesenteric artery was decreased significantly, the media thickness and media/lumen of mesenteric artery were increased significantly in the model group, compared with the normal control group. However these effects were reversed by 17 -β- estradiol in the 17 -β- estradiol replacement group. But the remodeling indexes of aorta had no sigrificant difference among the groups. Conclusions 17-β- estradiol inhibited insulin resistance and the form of mesenteric artery remodeling in ovariectomized rats fed with the high fructosc diet.