Plasma levels of endothelin-1, angiotensin II, nitric oxide and prostaglandine E-[2] in the venous and cavernous blood of patients with erectile dysfunction

ABSTRACT

To investigate the balance between the release of the smooth muscle vasoconstrictors [endothelin-l [ET-1] and angiotensin II [Ang II]] and relaxants [nitric oxide [NO] and prostaglandin E-[2] [PGE-[2]]] by determining the alterations in plasma levels of ET-l, Ang II, NO and PGE2 in the venous and cavernosal blood of patients with organic and psychogenic erectile dysfunction [ED]. Patients The study included 32 patients complaining of ED for more than one year [mean age +/- SEM 43.7 +/- 2.07]. The patients were subdivided into two groups 16 organic ED patients [mean age +/- SEM 48.13 +/- 2.77 years] and 16 psychogenic ED patients [mean age +/- SEM 43.0 +/- 3.03 years]. Fifteen healthy potent age matched [mean +/- SEM 44.86 +/- 2.9 years] male volunteers were enrolled as a control group. For each patient venous and cavernous blood were obtained, while only venous blood were obtained from controls. Design: A randomized, group comparative, single-center study. Setting: Assiut University Hospital. Intervention Plasma levels of ET- 1, Ang II, NO and PGE-[2] in the venous and cavernous blood of ED patients and in the venous blood of controls were estimated. Main outcome measures: ET-1, Ang II, NO and PGE-[2]. The present study showed significant increase in the plasma levels of ET-1 and Ang II, in addition to significant decrease in the plasma levels of NO and PGE[2] in the venous blood of ED patients in comparison to the controls. Patients with organic ED showed significant higher levels of ET- 1 and significant lower levels of NO in both venous and cavernous blood in comparison to those with psychogenic ED. Significant higher levels of cavernous Ang H were found in the two groups of ED patients in relation to venous blood. However, there were also no significant differences in PGE[2] levels in venous and cavernous blood of both groups of patients. There were significant positive correlations in both venous and cavernous blood between ET-l and Ang II and between NO and PGE[2] in total ED patients and the two subgroups. In addition significant negative correlations were found between venous and cavernous ET- 1 and NO; ET-1 and PGE[2] Ang II and NO and between Ang II and PGE[2] The imbalance between vasoconstrictors and vasodilators may play an important role in the pathogenesis of erectile dysfunction. ET- 1 may be a clinical marker of diffuse endothelial disease manifested by ED. Since ACE activity controls Ang II there might be a rationale for the use of ACE inhibitors to prevent or treat ED. NO and PGE2 may provide new strategies for pharmacologic treatment of ED