17β-雌二醇对去卵巢SD大鼠小肠动力的影响

Effects of 17β-estradiol on small intestinal motility in ovariectomized SD rats

目的探讨外源17β-雌二醇对去卵巢SD大鼠小肠动力的作用。方法建立去卵巢SD大鼠模型,体内研究给予不同浓度17β-雌二醇后,单向方差分析比较在体小肠推进比的差异,了解小肠传输功能的变化;体外研究制作小肠肠段,采用张力转换仪及生物机能实验系统测量该肠段在10-4mol/L卡巴胆碱作用后,按浓度梯度依次加入17β-雌二醇、雌激素受体拮抗剂氟维司群(Fulvestrant)后,重复测量方差分析和单向方差分析离体小肠肠段张力的改变。结果 (1)17β-雌二醇可降低去卵巢SD大鼠小肠推进比,且随其浓度增高而增强(P<0.01)。(2)单纯加入10-4mol/L的卡巴胆碱可以使去卵巢SD大鼠离体小肠平滑肌张力增强,17β-雌二醇可抑制此效应,且随其浓度的增加抑制效应逐步增强(P<0.01),该抑制作用可被同浓度的雌激素受体拮抗剂氟维司群明显抵消(P<0.01)。结论 (1)17β-雌二醇可抑制去卵巢SD大鼠的小肠传输功能,并与其浓度呈正相关,可能在小肠动力减弱中起一定作用。(2)17β-雌二醇可抑制去卵巢SD大鼠离体小肠平滑肌收缩,与浓度呈正相关;该抑制作用可能通过与小肠平滑肌上的雌激素受体结合途径发挥作用。

Objective To investigate the effects of exogenous 17β-estradiol on small intestinal motility of ovariectomized SD rats. Methods The intestinal propulsion rates were compared among ovariectomized Sprague Dawley rats in order to find out the changes of small intestinal transmit by treatment with different concentrations of 17β-estradiol and statistic analysis by single variance analysis in vivo. The prepared small intestinal segments of ovariectomized SD rats were treated with the concentration of 10^-4 mol/L carbachol, and then the intestinal smooth muscular tensions were measured by muscular tension converter and BL-420E biological function experiment system. These carbachol-treated intestinal segments were exposed to different concentrations gradients of 17β-estradiol and estrogen receptor antagonist Fulvestrant （from 10^-8 mol/L to 10^-4 mol/L） in turn, the muscular tensions in different groups were recorded, then statistic analysis by repeated measures variance analysis and single variance analysis in vitro. Results （ 1 ） Exogenous 17β- estradiol could decrease intestinal propulsion rates of ovariectomized SD rats in vivo; furthermore, the higher concentration of 17β-estradiol, the stronger inhibition （P 〈 0.01 ） ; （2） 10^-4 mol/L of carbaehol could enhance the muscular contraction of small intestinal segments of ovariectomized SD rats, but the contraction could be inhibited by exogenous 17β-estradiol. This inhibition effect became stronger with 17β-estradiol concentration upgrade （ P 〈 0.01 ） , moreover, it could be eliminated by the same concentrations of estrogen receptor antagonist Fulvestrant （P 〈 0.01 ）. Conclusion （ 1 ） 17β-estradiol can inhibit intestinal transit of ovariectomized SD rats; the inhibition effect correlated with the concen- tration of 17β-estradiol may slow down small intestine motility. （2） 17β-estradiol can inhibit the muscular contraction of small intestinal segments caused by carbachol in ovariectomized SD rats. And the inhibition effect correlated with the concentration of 17β-estradiol may play a role through the estrogen receptor pathway.