Question

Explain why the combination of treatment with an antagonist to norepinephrine and treatment with a VIP agonist would be the most effective way to increase blood flow to the genitals.

Answer 1

*In the Pen*s erectile tissues are present called Corpus Cavernosa. Inside Corpus Cavernosa Smooth muscle cells are present which when relaxed cause the increase in flow of blood and erection of Pen*s.Also arterioles are present which when relaxed cause increase in blood flow .

*Erection of Pen*s is physiological but if there is any problem in this physiological process it result in Dysfunction of Pen*s called Erectile Dysfunction .

*Various agents are used for Erectile Dysfunction In combination or as single drug .One of the Combination is VIP agonist and NOr adrenaline antagonist .

*Now VIP is Vasoactive intestinal Peptide .It is located in Neuronal fibres innervating the corpus Cavernosa and pen*s vasculature .Function of VIP is smooth muscle relaxation and it acts on smooth muscle cells of Corpus Cavernosa and result in Increases in blood flow of Genitalia and erection of Pen*S.

*Now Nor Adrenaline is Sympathetic agent and sympathetic nervous system is responsible for Ejaculation( removal ) of Sperms from Pen*S. It acts on Alpha 1 receptor on blood vessels and result in Vasoconstriction and also on Smooth muscle cells of corpus Cavernosa and it's contraction result in Ejaculation of Sperms .Hence when Nor Adrenaline antogonist like Prazosin is used then Vasoconstriction does not occur and thus Prolonged Vasodilation result in increased blood flow in genitals and erection of Pen*S.

Hence Combination of Both VIP and NOr adrenaline antagonist is used to maintain the blood flow in Pen*S and maintain Erection .