α-玉米赤霉醇改善去卵巢高同型半胱氨酸血症大鼠的血管功能

Improvement of vascular function by α-Zearalanol in ovariectomized hyperhomocysteinemic rats

目的探讨植物雌激素α-玉米赤霉醇(α-ZAL)对去卵巢高同型半胱氨酸血症(HHcy)大鼠血管功能的保护作用。方法用高蛋氨酸(Met)饮食复制HHcy大鼠模型。40只雌性Wistar大鼠随机分为5组:(1)对照组(Con);(2)2.5%蛋氨酸组(Met);(3)卵巢切除+2.5%蛋氨酸组(OVX+Met);(4)卵巢切除+2.5%蛋氨酸+α-ZAL组(OVX+Met+α-ZAL);(5)卵巢切除+2.5%蛋氨酸+17β-E2组(OVX+Met+17β-E2)。12周后,测定血浆雌二醇(E2)及同型半胱氨酸(Hcy)的含量;离体胸主动脉环灌流,观察胸主动脉环对不同浓度苯肾上腺素(PE)、乙酰胆碱(ACh)和硝普钠(SNP)的反应。结果高蛋氨酸饮食可明显增高血浆Hcy水平,其中OVX+Met组大鼠Hcy水平升高最显著。与其他组相比,OVX+Met组大鼠胸主动脉环对PE的收缩反应明显增强,对ACh的舒张反应明显减弱。各组大鼠胸主动脉环对SNP的舒张反应无明显差异。结论α-ZAL可抑制去卵巢HHcy大鼠血浆Hcy水平的升高,减轻血管内皮细胞的损伤,明显改善大鼠的血管功能,其作用与17β-E2相似。

Objective To investigate the effects of phytoestrogen α-zearalanol（α-ZAL） on vascular function in ovariectomized hyperhomocysteinemic rats.Methods Hyperhomocysteinemia was induced by feeding with high-methionine diet.Forty female Wistar rats were divided randomly into 5 groups：（1） Control（Con）;（2） 2.5% Methionine（Met）;（3） Ovariectomy＋2.5% Methionine（OVX＋Met）;（4） Ovariectomy＋2.5% Methionine＋α-ZAL（OVX＋Met＋α-ZAL）;（5） Ovariectomy＋2.5% Methionine ＋ 17β-estradiol（OVX＋Met＋17β-E2）.12 weeks later,blood was collected to analyze plasma estradiol and Hcy levels.Thoracic aortas were isolated to detect the response to phenylephrine（PE）,acetylcholine（ACh） and sodium nitroprusside（SNP）.Results The plasma Hcy levels were elevated in all rats fed with 2.5% methionine diets,especially in the OVX＋Met group.In a dose-dependent manner,PE elicited significantly greater contraction in thoracic aorta rings taken from rats ofOVX＋Met than that taken from other groups and ACh elicited significantly less percentage relaxation in thoracic aorta rings.There was no significant difference in response to SNP.Conclusion α-ZAL may remarkably improve vascular function in ovariectomized HHcy rats via attenuating elevation of plasma Hcy and endothelial cells damage,which is similar to 17β-E2.