OBJECTIVETo investigate the role of endogenous hydrogen sulfide (H2S) in erectile dysfunction (ED) induced by androgen deficiency.

METHODSWe randomly divided 30 eight-week-old healthy male SD rats into six groups: 2-week control (A), 4-week control (B), 2-week castration (C), 4-week castration (D), 2-week castration + androgen replacement (E), and 4-week castration + androgen replacement (F), those in groups E and F subcutaneously injected with testosterone propionate (TP) at the physiological dose of 3 mg/kg per day after castration, while those in the other groups with isodose oil instead. At 2 and 4 weeks after operation, we determined the level of serum testosterone (T) , intracavernous pressure (ICP) , mean carotid arterial pressure (MAP) of the rats, measured the concentration of H2S in the plasma and corpus cavernosum tissue, and detected the expressions of cystathionine-P3-synthase (CBS) and cystathionine-gamma-lyase (CSE) by immunohistochemistry and Western blot.

RESULTSThe serum T level was significantly lower in group C ([0.63 +/- 0.15] nmol/L) than in A ( [ 16.55 +/- 4.17] nmol/L) and E ( [ 18.99 +/- 4.62] nmol/L) (P <0.05), as well as in group D ([0.70 +/-0.22] nmol/L) than in B ([15.44 +/-5.18] nmol/L) and F ([20.99 +/-6.41] nmol/L) (P <0. 05) , and so were ICP/MAP after 5 and 7 V electrical stimulation of the pelvic ganglia (P <0. 05) , H2 S concentration (P <0.05), and the expressions of CBS and CSE (P <0.05). The expressions of CBS and CSE proteins were also significantly decreased in group C as compared with D (P <0.05).

CONCLUSIONThe reduced expressions of CBS and CSE may inhibit the H2 S signaling pathway, which might be one of the mechanisms underlying androgen deficiency-induced ED in rats.