Early administration of phosphodiesterase 5 inhibitors after induction of diabetes in a rat model may prevent erectile dysfunction.

BACKGROUND: The possible role of phosphodiesterase 5 inhibitors (PDE5Is) in prevention of negative effect of diabetes mellitus (DM) on erectile function is not well settled. OBJECTIVES: To investigate the effect of early administration of vardenafil on erectile function, cavernosal structure, and genes expression in a rat model of DM. MATERIALS AND METHODS: This experimental study was carried out at Suez Canal University's research laboratory. This study was conducted on a total of 60 adult male Albino Wistar rats, aged 60-80 days and weighing an average of 200 g. Rats were equally divided into six groups of 10 rats each: Group I (sham); Group II (DM with no treatment); Groups III, IV, V, and VI received vardenafil started at day 1, week 4, week 8, and week 12 after induction of DM, respectively. Functional study assessment of all groups was performed before euthanization, and then tissues were harvested for histopathological, ultrastructural, and molecular examinations. RESULTS: There was a significant difference of intracavernosal pressure between early (94 ± 2.18) and late (40.5 ± 1.94) treatment groups (p = 0.011). Histopathological and ultrastructural changes of DM with no treatment and late treatment groups showed distorted cavernous architecture and extensive fibrosis. There was significant difference of smooth muscle to collagen ratio between early and late treatment groups (p = 0.035). There was significant upregulation of nNOS(p = 0.021) and iNOS (p = 0.047) in early vs. late treatment group. The difference was insignificant in eNOS (p = 0.386) or TGF-ß1(p = 0.149). DISCUSSION AND CONCLUSION: Early treated rats with vardenafil had preserved erection and normal cavernosal structure, ultrastructure and gene expression of iNOS, nNOS, eNOS, and TGF-ß1. Quantification of gene expression would improve our knowledge regarding cytokines expression and molecular background of DM-associated ED. Clinical application of this result may encourage early administration of PDE5I to prevent deleterious effects of DM on erectile function in newly diagnosed DM patients with probable uncontrolled blood glucose.

Testosterone level and endothelial dysfunction in patients with vasculogenic erectile dysfunction.

The association between endothelial dysfunction and late onset hypogonadism (LOH) in patients with vasculogenic erectile dysfunction (ED) is not yet well settled. Our objective was to assess the association between LOH and endothelial dysfunction in patients with vasculogenic ED. Throughout 2014-2015 a total of 90 men were enrolled in this cross-sectional observational study. Of them 60 patients with a clinical diagnosis of ED were further subdivided into two equal groups: patients with vasculogenic ED and LOH (A); patients with vasculogenic ED and euogonadal (B). Thirty age-matched men with no ED or hypogonadism were enrolled as control group (C). All patients were subjected to detailed medical and sexual history, total testosterone (TT), calculated free (FT) and bioavailable testosterone (BT), flow cytometric evaluation for endothelial progenitor cells (EPCs) (CD45negative/CD34positive/CD144positive) and endothelial microparticles (EMPs) (CD45negative/CD144positive/annexin V positive). The mean age ± SD of the three groups A, B and C were 51.3 ± 11.1, 53.6 ± 10.6 and 48.3 ± 5 years, respectively, with insignificant age differences (p = 0.089). The diagnostic criteria of LOH were adapted according to European male aging study, 2010. The means of TT(ng/mL) were 2.32 ± 0.21, 6.43 ± 0.36 and 5.37 ± 0.30 in groups A, B and C, respectively. There were highly significant differences between group A and groups B and C (p < 0.001 for each). The means of EPCs were 0.43 ± 0.070, 0.22 ± 0.05 and 0.032 ± 0.013 in groups A, B and C, respectively. The means of EMPs were 0.15 ± 0.029, 0.056 ±  .013 and 0.014 ± 0.002 in groups A, B and C, respectively. There were significant differences between group C and groups A and B (p < 0.05 for each). This study clearly demonstrated that there is a significant association between LOH and the higher expression of EPCs and EMPs in patients with vasculogenic ED.