5-氨基咪唑4-氨甲酰核糖核苷对大鼠子宫平滑肌收缩功能的影响

 目的 研究5-氨基咪唑4-氨甲酰核糖核苷(AICAR)对子宫平滑肌的收缩特性的影响。方法 分离孕SD大鼠和未孕SD大鼠的子宫平滑肌，制备子宫肌条，采用累积给药法加入5-氨基咪唑4-氨甲酰核糖核苷或双丁酸环腺苷酸（dibutyryl-cAMP，dbcAMP）（浓度从10^-9 到10^-4 mol·L^-1）， 或采用5-氨基咪唑4-氨甲酰核糖核苷或双丁酸环腺苷酸预孵（浓度10^-5 mol·L^-1）未孕大鼠子宫平滑肌，然后采用乙酰胆碱及缩宫素诱导子宫平滑肌收缩，利用RM6240-BD生物信号采集系统记录子宫平滑肌收缩幅度的变化。结果 5-氨基咪唑4-氨甲酰核糖核苷或双丁酸环腺苷酸对孕鼠和未孕鼠的子宫平滑肌收缩幅度均呈浓度依赖性抑制。对孕大鼠子宫平滑肌，在浴槽浓度达10^-7 mol·L^-1时，能产生显著抑制作用（P<0.01），-log (IC₅₀)分别为7和7.5。对未孕大鼠子宫平滑肌，5-氨基咪唑4-氨甲酰核糖核苷和双丁酸环腺苷酸对乙酰胆碱及缩宫素诱导的子宫平滑肌收缩均有明显抑制作用。结论 5-氨基咪唑4-氨甲酰核糖核苷对孕鼠及未孕鼠子宫平滑肌的收缩均有明显抑制作用，提示其具有松弛子宫平滑肌作用。

The Effect of AICAR on Rat Uterine Smooth Muscle

OBJECTIVE To study the effect of AICAR on uterine smooth muscle of pregnant and nonpregnant rats.METHODS The action of AICAR and dibutyryl-cAMP on the contractile function of isolated myometrium of pregnant and nonpregnant Sprague-Dawley rats was investigated.AICAR or dibutyryl-cAMP was used at cumulative doses from 10-9 to 10-4 mol·L-1 for myometrium of pregnant rats,and at 10-5 mol·L-1 for myometrium of nonpregnant rats.The amplitude of the contractility of myometruim was recorded.RESULTS For the myometrium of pregnant or nonpregnant rats,AICAR and dibutyryl-cAMP exerted strong inhibitory action on the contractile function in dose-dependent manners.For the myometrium of pregnant rats,AICAR or dibutyryl-cAMP showed inhibitory effect at a low concentration of 10-7 mol·L-1.AICAR and dibutyryl-cAMP also caused significant inhibition in myometrium from nonpregnant rats.CONCLUSION AICAR exerted strong inhibitory action on the contractile function of myometrium from pregnant or nonpregnant rats,suggesting that AICAR may have inhibitory effect on spontaneous activity of myometrium of human.