Objective: To study the expression of heme oxygenase (HO) in the corpus cavernosum of castrated rats and to investigate its role in androgen deficiency-mediated erectile dysfunction.
Methods: Forty 10-week old SD rats were randomly divided into Groups A (2-week sham operation), B (4-week sham operation), C (2-week castrated) and D (4-week castrated). The serum testosterone level was determined, and the expressions of HO and nNOS in the corpus cavernosum of the castrated rats were detected by immunohistochemical staining and RT-PCR 2 and 4 weeks after the operation.
Results: Compared with the sham operation groups, the castrated rats showed a significant reduction in the level of serum testosterone, (A vs. C: [283.222 +/- 117.171] ng/dl vs. [7.117 +/- 3.700] ng/ dl; B vs. D: [289.280 +/- 87.413] ng/dl vs [48.826 +/- 19.477] ng/dl) (P < 0.01), the expressions of HO-1 and HO-2 proteins (P < 0.01) and the expressions of HO-1, HO-2 and nNOS mRNA (P < 0.01).
Conclusion: Androgen can partly regulate the erectile function of the penis via the HO-CO system.