卵巢切除术及激素替代疗法对雌兔膀胱功能的影响

Effects of ovariectomy and estrogen replacement therapy on the bladder function of female rabbits

目的观察卵巢切除术及激素替代疗法对雌兔膀胱功能的影响。方法选择雌性大白兔21只,随机分为3组。第一组为对照组,假手术,手术后1周起每只动物皮下注射生理盐水,共8周。第二组为卵巢切除组,单纯行双侧卵巢切除术,手术后1周起每只动物皮下注射生理盐水。第三组为雌激素组,行双侧卵巢切除术,手术后1周起每只动物皮下注射17-β雌二醇。8周后每只动物取血,测定血清雌二醇的浓度。动物麻醉后,应用尿流动力检测仪检测膀胱容量、逼尿肌压力、膀胱顺应性。检测后取出膀胱,称膀胱湿质量。取膀胱平滑肌组织,测量记录平滑肌张力的变化。试验后,每条平滑肌标本称质量。结果卵巢切除组的血清雌二醇水平、膀胱容量和膀胱顺应性相对于对照组减少,膀胱湿质量和逼尿肌压力与对照组比较差异无统计学意义。雌激素组的血清雌二醇水平、膀胱湿质量和膀胱容量较对照组显著增加,而膀胱顺应性和逼尿肌压力与对照组比较差异无统计学意义。卵巢切除组的膀胱平滑肌组织对2 Hz电刺激的反应较对照组显著减小。经过8周雌激素治疗的动物膀胱平滑肌组织对2 Hz电刺激的反应较对照组和卵巢切除组均显著增加。膀胱平滑肌组织对8 Hz及32 Hz电刺激的反应与对2 Hz电刺激的反应是一致的。膀胱平滑肌组织对卡巴胆碱、ATP及KCl反应与对电刺激的反应是一致的。结论卵巢切除使雌兔血清雌二醇水平显著降低,膀胱容量和顺应性下降,膀胱平滑肌条对电刺激、卡巴胆碱、ATP、KCl诱导的收缩反应减低。雌激素可逆转这些反应,增加膀胱湿质量。雌激素水平的变化对膀胱功能有显著影响。

Objective It is to explore the effects of ovariectomy and estrogen replacement therapy on the bladder function of female rabbits.Methods Twenty one female white rabbits were randomly divided into 3 groups.Group 1 served as control group,received sham operation and 8 weeks＇ treatment with normal saline by hypodermic injection in 1 weeks after operation.Group 2 served as ovariectomy group,received ovariectomy and treatment 8 weeks＇ treatment with normal saline by hypodermic injection in 1 weeks after operation.Group 3 served as estrogen group,received ovariectomy and treatment with 17-βestradiol by hypodermic injection in 1 weeks after operation.At the end of the 8 weeks＇ treatment,blood samples were obtained from each rabbit to determine the content of serum estradiol.Then each rabbit was anesthetized to detect bladder capacity,detrusor pressure and compliance by urodynamic testing machine.After urodynamic test the bladder was removed and weighed.The smooth muscle strips were cut from the bladder body to measure the tension change.At the end of the experiment the strips were weighed.RusultsIn ovariectomy group,serum estradiol,bladder capacity and bladder compliance were obviously lower than those in control group（P〈0.05）,but bladder wet weight and detrusor pressure were similar to those of control group（P〉0.05）.Estrogen administration resulted in a significant increase in serum estradiol,bladder wet weight and bladder capacity compared with control group,except in bladder compliance and detrusor pressure.As for the contractile responses of bladder strips to field stimulation,the bladders from the ovariectomy group showed decreased responses to 2 Hz compared with those from the control group.After 8 weeks＇ estrogen treatment,the contractile responses to 2 Hz increased significantly compared with those in the control group and ovariectomy group.The contractile responses to 8 Hz and 32 Hz of bladder strips were similar with the contractile responses to 2 Hz.The contractile responses to carbachol,ATP and KCl of bladder strips were similar with the contractile responses to field stimulation.Conclusion While ovariectomy resulted in a significant decrease in serum estradiol of female rabbit,bladder capacity and compliance showed decline,the contractile responses of bladder strips decreased to all forms of stimulation（field stimulation,carbachol,ATP,KCl）.Estrogen administration could reverse these effects and increase bladder wet weight.Bladder function can be significantly affected by modulating the circulating estrogen level.