性激素对卵巢切除后大鼠膀胱结构和功能的作用

Effects of sex hormones on bladder function and structure： experiment with ovariectomized female rats

目的探讨性激素对卵巢切除后大鼠膀胱结构和功能的作用。方法将70只成年雌性大鼠平均分成7组进行假手术和双侧卵巢切除。除假手术组和单纯卵巢切除组外分别给予苯甲酸雌二醇0．25mg/kg、苯甲酸雌二醇1mg/kg、黄体酮、苯甲酸雌二醇0.25mg／kg和黄体酮、丙酸睾酮，隔日肌注，4周后处死。光镜和电镜下观察大鼠膀胱形态学变化。结果双侧卵巢切除后，膀胱壁变薄为（0．97±0．11）mm（P〈0.05），雌激素和雄激素均可使膀胱重量和膀胱壁厚度明显增加，甚至超过假手术组（P〈0.05）。卵巢切除后膀胱逼尿肌肌间隙增大，肌细胞退变。雌激素和雄激素可以逆转此反应，高剂量的雌激素增生作用反而减弱，并使逼尿肌出现大量胞质空泡。孕激素对膀胱结构的影响不明显，但有削弱雌激素作用的趋向。结论体内雌激素和雄激素水平对膀胱结构有重要影响，两者均能促进膀胱逼尿肌增生。大剂量的雌激素可能损害肌细胞结构，孕激素可削弱雌激素对膀胱的作用。

Objective To investigate the effects of sex hormones on bladder and mechanism thereof. Methods Sixty mature female SD rats underwent bilateral ovariectomy and then randomly divided into 6 groups： low dose estrogen group （ OVX ＋ E group） treated with estradio] benzoate 0. 25 mg/kg injected intramuscularly qod, high dose estrogen group （ OVX ＋ E 1 mg group） treated with estradiol benzoate 1 mg/kg, progesterone （P） group, treated with P 1 mg, OVX ＋ E ＋ P group treated with estradiol benzoate 0.25 mg/kg ＋ progesterone 1 mg, d androgen group （ OVX ＋ T group） treated with testosterone propionate 3 mg/kg, and untreated ovariectomized group （OVX group） receiving no medication, Another 10 rats underwent sham operation. Four weeks later the rats were killed with their bladders and urethras taken out to undergo light and electron microscopy. Results The thickness of bladder wall of the OVX group was （0.97 ± 0.11 ） mm, significant thinner than that of the sham operation group [ （ 1. 10 ± 0. 1 ） mm, P 〈 0.05 ） ]. The thickness levels of bladder walls of the OVX ＋ E and OVX ＋ T groups were （ 1.23 ± 0.12） mm and （1.26 ±0.12 mm） respectively, both significantly thicker than that of the OVX group （both P 〈0. 01 ） Wider spaces between the detrusor muscle fascicles and degeneration of detrusor muscle cells were seen in the bladder walls of the OVX group, and such phenomena were milder in the OVX ＋ E and OVX ＋ T groups, however, wider spaces between the detrusor muscle fascicles could be seen in the OVX ＋ E ＋ P group too. The hypertrophic effect on the detrusor muscle of the OVX ＋ E 1 mg group was weaker than that of the OVX ＋ E group, a lot of cytoplasmic vacuoles was seen in the 2 groups treated with E, especially the OVX ＋ E 1 mg group. The bladder structure of the OVX ＋ P group was similar to that of the OVX group. Conclusion Endogenous testosterone level as well as estrogen level can significantly affect the bladder structure with a hypertrophic effect on bladder detrusor muscle. But higher doze of estrogen also has some unexpected effects which may destroy bladder structure. In addition, progesterone can compromise the effect of estrogen.