一氧化氮对大鼠前列腺增殖/凋亡的影响

目的 探讨一氧化氮（NO）对大鼠前列腺上皮增殖／凋亡的影响。方法 20只成年雄性SD大鼠随机分为3组，第一组为正常对照组（6只），第二、三组皮下注射一氧化氮合酶（NOS）抑制剂L-NAME（各7只），注射剂量分别为50mg／kg，2次／d及100mg／kg，2次／d。2周后观察各组大鼠前列腺重量和组织学变化，Ki-67免疫染色及TUNEL染色测定前列腺上皮细胞的增殖和凋亡指数，免疫组织化学染色及逆转录-聚合酶链反应（RT-PCR）法检测NOS3种亚型的蛋白及mRNA表达情况。结果 3组大鼠的前列腺重量差异无统计学意义（P〉0．05）；与第一组相比，第二、三组大鼠前列腺上皮细胞萎缩较明显。Ki-67及TUNEL染色显示上皮和间质细胞增殖率明显降低，上皮细胞凋亡率明显升高（P〈0．05），NOSl和NOS3蛋白及mRNA表达水平显著下降。3组NOS2表达均不明显。结论 NO可能影响前列腺细胞增殖及凋亡，在BPH的发病机理中具有重要作用。

Effect of nitric oxide on the prostatic proliferation/apoptosis in rats

Objective To investigate the effect of nitric oxide(NO)on the prostatic proliferation/apoptosis in rat models. Methods Twenty adult male rats were randomly divided into 3 groups.Group 1 were normal controls (n=6);group 2 (n=7) and group 3 (n=7) were treated with subcutaneous injection of nitric oxide synthase (NOS) inhibitor-L-NG-Nitroarginine methyl ester (L-NAME) 50mg/kg and 100mg/kg, bid, respectively.The weight of the prostate was measured after 2 weeks and morphological changes were examined with light microscope.Detection of ki-67 and TUNEL in prostatic epithelial cells were undertaken so as to assess the proliferation and apoptosis index.The protein and mRNA expression of NOS were analyzed by means of immunohistochemistry and RT-PCR. Results The prostate weight of 3 groups was not significantly different.Compared with group 1, remarkable atrophy of prostatic epithelial cells,marked decrease in proliferation rate of epithelial and interstitial cells, and significant increase in apoptosis rate of epithelial cells were noted in group 2 and group 3 (P<0.05);the protein and mRNA expression of NOS1 and NOS3 were down regulated in group 2 and group 3 (P<0.05).Little NOS2 was expressed in the 3 groups. Conclusions These results suggest that NO may play an important role in the pathogenesis of BPH by affecting proliferation and apoptosis of the prostatic cells.