血红素氧合酶2在去势大鼠阴茎海绵体内的表达

目的:研究去势大鼠阴茎海绵体血红素氧合酶2(HO-2)和内皮型一氧化氮合酶(eNOS)的表达,探讨雄激素与HO-2、eNOS在ED中的作用及相关性。方法:10周龄雄性SD大鼠40只,分为4、8、12周组和正常对照组各10只,实验组采取手术切除双侧睾丸,对照组采取假手术。分别于术后4、8、12周测定大鼠血清睾酮(T)、阴茎海绵体内压(ICP)、平均颈动脉压(MAP),取阴茎标本,采用Western印迹分析阴茎海绵体HO-2含量,免疫组化分析HO-2和eNOS的表达。结果:去势各组血清T水平较正常对照组显著下降(P<0.05)。经3V、5V电压刺激后去势各组ICP/MAP值明显下降(P<0.05)。HO-2在正常和去势大鼠阴茎海绵体组织均有表达,去势4周组HO-2光密度分布曲线下面积(341.50±99.70)较正常组(876±443.36)和去势8周组(705.00±152.74)明显下降(P<0.05),去势8周与正常组之间无显著变化(P>0.05),去势12周没有检测到HO-2的表达。eNOS主要表达于阴茎海绵体血管内皮细胞,去势组eNOS(123.94±30.23)较正常组(421.21±125.12)差异有显著性(P<0.05)。T与eNOS和HO-2表达呈高度正相关(r=0.976、0.946,P均<0.05)。结论:雄激素可能通过影响大鼠阴茎海绵体HO-2、eNOS的表达参与阴茎勃起功能调控。

Expression of Heme Oxygenase 2 in the Corpus Cavernosum of Castrated Rats

OBJECTIVE: To determine the expressions of HO-2 and eNOS in the corpus cavernosum of castrated rats and investigate the correlation of HO-2 and eNOS with erectile dysfunction. METHODS: Forty SD rats of 10 weeks were equally divided into 3 castrated groups (4, 8 and 12 weeks respectively after removal of bilateral testes) and a sham operation control group. All the rats were detected for serum testosterone (T), intracavernosal pressure (ICP) and mean arterial blood pressure (MAP) 2, 8 and 12 weeks after the surgery, the content of HO-2 analyzed by Western blot and the expressions of eNOS and HO-2 determined by immunohistochemistry. RESULTS: Testosterone level and ICP/MAP ratio were markedly decreased after the castration (P < 0.05). The HO-2 expression was detected in the corpus cavernosum of all but the 12-week castrated rats, and the area under the curve was (341.50 +/- 99.70) in the 4-week castrated group, significantly less than in the 8-week (705.00 +/- 152. 74) and the control group (876 +/- 443. 36) (P < 0. 05), with no obvious difference between the latter two. eNOS was found mainly in the vascular endothelial cells of the corpus cavernosum, significantly less in the castrated (123.94 +/- 30. 23) than in the control group (421.21 +/- 125. 12). CONCLUSION: Androgens might mediate the penile erectile function through HO-2 and eNOS in the corpus cavernosum of rats.