[Expressions of eNOS and connexin 43 in the penile tissue of rats with diabetic erectile dysfunction].

OBJECTIVE: To investigate the expressions of endothelial nitric oxide synthase (eNOS) and connexin 43 (Cx43) in the penile tissue of rats with diabetes mellitus induced erectile dysfunction (DMED) and their correlation with DMED.

METHODS: SD rat models of DM were established by intraperitoneal injection of alloxan, and 8 weeks later, apomorphine was administered to induce ED in the DM models. The expressions of eNOS and Cx43 were measured by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively.

RESULTS: Alloxan did not influence the expressions of eNOS mRNA and Cx43 mRNA in the penile tissue. Compared with the DM models, the expression of eNOS mRNA significantly decreased in the DMED group (0.155 +/- 0.157 vs 0.508 +/- 0.242, P < 0.01), while that of Cx43 mRNA markedly increased (0.993 +/- 0.157 vs 0.545 +/- 0.138, P < 0.01), with a negative correlation between the two expressions (r = -0.987). The same results were shown by immunohistochemistry in the penile smooth muscle cells of the DMED rats.

CONCLUSION: The decrease of eNOS expression in the penile tissue might play a key role in the development of ED in diabetic patients, while the accompanying compensative elevation of the Cx43 level has yet to be further studied.