[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.