不同雌激素对慢性间歇性低氧去卵巢大鼠颏舌肌功能的影响比较

目的:探讨不同雌激素对慢性间歇性低氧(CIH)去卵巢大鼠颏舌肌功能的影响。方法:将40只8周龄健康雌性SD大鼠去卵巢后随机分为5组:正常氧组(NC)、慢性间歇性低氧组(CIH)、CIH雌二醇干预组(E2)、CIH金雀异黄素干预组(GEN)、CIH白藜芦醇干预组(RES)。后4组建立CIH大鼠模型,建模最后4 d,E2组、GEN组、RES组分别给予雌二醇、金雀异黄素、白藜芦醇2.5 mg/kg/d腹腔注射,NC组、CIH组给予相应剂量DMSO腹腔注射。建模后麻醉大鼠,分离颏舌肌,电脉冲刺激舌下神经中央支诱发颏舌肌收缩,检测颏舌肌收缩功能。结果:①各组大鼠颏舌肌单刺激收缩最大张力(Pt)与强直收缩最大张力(Po)无明显差异(P>0.05);②各组大鼠抗疲劳性比较,E2组、GEN组、RES组高于CIH组(P<0.01),E2组稍低于NC组,但无统计学差异(P>0.05),GEN组、RES组低于NC组、E2组(P<0.01),RES组高于GEN组,但差异无统计学意义(P>0.05)。结论:植物雌激素能一定程度恢复慢性间歇性低氧造成的去卵巢大鼠颏舌肌肌功能下降,但效果不如雌二醇,其作用机制有待进一步探讨。

Effects of different estrogen on genioglossus function of ovariectomized rats with chronic intermittent hypoxia

Objective： To investigate the effects of different estrogen on genioglossus （GG） function of ovariectomized rats with chronic intermittent hypoxia. Method： Forty female SD rats （8 weeks old） were randomly divided into five groups after ovariectomy： normoxia control group （NC）, chronic intermittent hypoxia group （CIH）, estradiol group （E2）, genistein group （GEN）, resveratrol group （RES）. Rats in the latter four groups were used to build CIH models. In the latter three groups, estradiol, genistein and resveratrol were administered respectively by intraperitoneal injection daily in the last 4 days of CIH exposure,and the dose was 2.5 mg/kg/day. Rats in the NC and CIH groups were intraperitoneally injected with DMSO as a control. After CIH exposure, the rats were anesthetized, and the GG were isolated. The contractile characteristics of the whole GG were measured in response to stimulation of the hypoglossal medial nerve branch. Result： 1.No significant difference was observed in twitch tension and initial tetanic tension between the five groups （P 〉0.05）. 2. A significant in- crease in GG fatigue resistance was observed in E2 group, GEN group and RES group compared with CIH group （P 〈0.01）. Only a slight decrease was examined in E2 group as compared with NC group （P 〉0.05）. The fatigue resistance of GEN group and RES group were observed to be significantly lower than that of NC group and E2 group （P 〈0.01）. Besides, there was an insignificant increase in RES group in contrast to GEN group （P 〉0.05）. Conclusion： Though being no match for estradiol, phytoestrogen could increase the fatigue resistance of GG in CIH ovariectomized rats to some extent, whose mechanism still need more research.