OBJECTIVETo investigate the effect of the overexpression of the ERbeta gene on the penile vascular endothelium of ERbeta knockout (ERbetaKO) mice and its molecular mechanisms.

METHODSWe randomly divided 12 ERbetaKO male mice into groups A (ERbetaKO + TNFalpha + pAdxsi-ERbeta) and B (ERbetaKO + TNFalpha + empty virus), the former treated by pAdxsi-ERbeta adenovirus transfection, the latter with empty virus, and meanwhile both injected intraperitoneally with TNFalpha at 6 microg per kg body weight per d for 14 days. Then we observed the erectile function of the mice by APO, determined the changes of the endothelial markers CD34 and vWF by immunohistochemical staining, and detected the expressions of the relevant molecules in the eNOS-NO pathway by RT-PCR, Western blot and immunohistochemistry.

RESULTSCompared with group B, group A showed a significantly increased number of penile erections (0.50 +/- 0.55 vs 2.17 +/- 0.41, P < 0.05), shortened erectile latency ([28.83 +/- 1.33] min vs [24.00 +/- 1.27] min, P < 0.05), enriched CD34 and vWF markers (0.67 +/- 0.52 vs 1.50 +/- 0.55 and 0.50 +/- 0.55 vs 1.33 +/- 0.52, both P < 0.05), elevated expressions of eNOS and Cam (RT-PCR: 1.38 +/- 0.03 vs 1.62 +/- 0.05 and 1.02 +/- 0.09 vs 1.42 +/- 0.05, both P < 0.05; Western blot: 1.27 +/- 0.04 vs 1.55 +/- 0.07 and 0.76 +/- 0.05 vs 0.95 +/- 0.08, both P < 0.05), and reduced expression of caveolin-1 (RT-PCR: 2.13 +/- 0.13 vs 1.72 +/- 0.08, P < 0.05; Western blot: 3.99 +/- 0.16 vs 3.40 +/- 0.14, P < 0.05). The results of RT-PCR were consistent with those of Western blot.

CONCLUSIONThe ERbeta gene protects the penile vascular endothelium via the eNOS-NO pathway.