Icariin improves SHR erectile function via inhibiting eNOS uncoupling.

The aim of the study was to investigate whether or not the effect of icariin on erectile function of SHR is associated with inhibition of eNOS uncoupling. Ten 12-week-old male WKY rats and 10 age-matched male SHR were evenly randomised into SHR control group, SHR+ icariin treatment group, WKY control group and WKY+ icariin group. After being treated for 4 weeks, ICPmax/MAP, the expression of NT, monomer and dimer of eNOS and the level of BH4, BH2, DHFR, NADPH oxidase and GTPCH1 in the corpus cavernosum were determined. The ICPmax/MAP and the value of BH4, DHFR and GTPCH1 in the SHR icariin treatment group were significantly higher than that of the SHR group and less than that of the WYK group and icariin-treated WKY group (p < 0.05). The value of BH2, NADPH oxidase, the ratio of eNOS monomers/dimmers and NT in the SHR icariin treatment group was significantly less than that of in the SHR group and higher than that of the WYK control group and icariin-treated WKY group (p < 0.05). Hypertension increases eNOS uncoupling in the corpus cavernosum of SHR. Inhibiting uncoupling of eNOS may be an important mechanism of icariin to improve SHR erectile function.