Effect of Low Androgen Status on the Expression of P2Y Receptors in the Corpus Cavernosum of Rats.

OBJECTIVE

To determine whether low androgen status impacts erectile function by regulating the expression of the G protein-coupled P2Y receptors (P2Y1, P2Y2, P2Y4, and P2Y6) in the corpus cavernosum penis of rats.

MATERIALS AND

METHODS

A total of 36 healthy, 8-week-old, male Sprague-Dawley rats were randomly allocated into 6 groups: 4 weeks of androgen replacement therapy post castration (group A); 4 weeks post castration (group B); 4 weeks post sham operation (group C); 8 weeks of androgen replacement therapy post castration (group D); 8 weeks post castration (group E); and 8 weeks post sham operation (group F). The ratio of maximum intracavernous pressure/mean arterial pressure was measured for every group and detected the expression of P2Y1, P2Y2, P2Y4, and P2Y6 in the rat corpus cavernosum penis of every group.

RESULTS

The ratio of maximum intracavernous pressure/mean arterial pressure significantly declined in the castration group compared with the control group (P <.01). The expression of P2Y1, P2Y2, P2Y4, and P2Y6 and the ratio of the phosphorylated endothelial nitric oxide synthase (eNOS)/eNOS proteins were significantly lower in the castration group vs treatment or control (P <.01) whereas they were significantly lower in the group of 8 weeks vs 4 weeks post castration (P <.05). The rat serum testosterone levels in every group were positively correlated with the protein levels of P2Y1, P2Y2, P2Y4, and P2Y6.

CONCLUSION

Downregulation of the expression of the P2Y1, P2Y2, P2Y4, and P2Y6 receptors that reduces the ratio of phosphorylated eNOS/eNOS and eNOS activity may be one of the important mechanisms of erectile dysfunction caused by low androgen status.