The endothelium is vital to the maintenance of vascular health. It is a critical determinant of vascular tone and patency, reactivity, inflammation, vascular remodeling, and blood fluidity. (9, 10). Nitric oxide (NO) is the most potent vasodilator and is secreted by the endothelium. It is synthesized from Larginine by the endothelial enzyme NO synthase (eNOS). NO released in response to sexual stimulation relaxes penile vascular smooth muscle by increasing intracellular cyclic 3′, 5′-guanosine monophosphate (cGMP) concentration. Vasodilatation of erectile tissues allows the sinusoidal spaces to fill with blood resulting in the attainment and maintenance of an erection (5).
In conclusion, aerobic training can successfully treat ED in selected patients with arterogenic ED. However, there are very few high-quality randomized trials regarding aerobic training and ED. Practitioners should bear in mind that aerobic training and other risk factors modification is associated with higher rates of ED management success.Since these results are based on small studies, the evidence would be stronger if confirmed by large trials. Effectiveness data were limited; however, the effectiveness of ED is largely determined by the patient health status and associated condition. In addition, work is needed in the standardization of follow-up protocols, evaluation of ED management success and failure, patient selection, and statistical analysis. More randomized studies that compare various exercise techniques are warranted. These studies should evaluate efficacy, complications, quality of life, cost implications, and long-term outcomes of ED management compare to other therapeutic modalities available. Also more database search is also warranted to further broaden the data search on the topic.
Parameters evaluated in this study are determinants of some important aspects of the male sexual competence. Libido index, intromission and mount latencies are indicators of libido, arousability and motivation. Copulatory efficiency and inter-copulatory intervals are indicators of sexual vigor, while penile thrusting is an indicator of penile erection.[8,11,14,15] Our results showed that the libido index was significantly reduced in the 10 mg/day zinc saulphate treated group. In the same group, majority of the animals (62%) failed to complete their sexual behavioral cycle within the observed period. Though these unsuccessful rats showed the initial steps of the cycle such as licking, physical contacts with the females and few mounts and intromissions, they were inactive at later stages. Therefore a significant reduction of the libido index, number of intromissions, mounts, and ejaculations were observed in the high dose of zinc treated group compared to controls.