Viagra to enhance sympathetically mediated vascular tone in humans

Nov 16, 2017

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Viagra to enhance sympathetically mediated vascular tone in humans

Posted in : Blog on by : Dr Richard Petty

Viagra is a medication that is used in the treatment of erectile dysfunction and is also useful in alleviating problems relating to impotency. This drug is being used from years together by a large number of men. Viagra helps men in achieving a hardcore erection that is long lasting and enables them to have a wonderful sexual experience. Viagra is known to boost erection by relaxing the muscles found in the walls of blood vessels and also increases the flow of blood to certain areas of the body, especially towards the genitals. This improved blood flow helps men to achieve a firm erection which helps them to have a wonderful sexual experience as they do not have the problem of erectile dysfunction when taking Viagra. Of late, scientists have found that Viagra apart from being used in treating ED and impotence issues, it can also be used for improving sympathetically mediated vascular tone in humans. You can read this blog in order to understand how Viagra plays a role in enhancing sympathetically mediated vascular tone in humans.

Research to establish if Viagra can be used to enhance sympathetically mediated vascular tone in humans

The active ingredient in Viagra i.e. sildenafil which is a selective phosphodiesterase type-5 inhibitor produces vasodilation which in turn improves the erectile dysfunction disorder and also the pulmonary hypertension. Sildenafil in Viagra could also cause baroreflex sympathetic activation which enhances vascular tone and also opposes direct vasodilation. Test was conducted in healthy men who were in their middle age so as to find out if the administration of sildenafil could increase sympathetically mediated vascular tone. The research thus conducted involved around nine men who were in their good health and the study was conducted in a double-blind crossover. These men were given a single dose of sildenafil in the dosage strength of 100mg to be taken orally. These men were also kept on placebo effect for about two days on a different time. The hemodynamics and also the forearm blood flow responses were measured at a baseline for about 30 and 45 minutes after the study of drug administration. This was also measured during intra-arterial infusions of vasoactive meds.

Efficacy of Viagra in improving sympathetically mediated vascular tone in humans

Once Viagra and placebo administration was done, intrabrachial meds were infused for testing forearm reform alpha receptor sensitivity i.e. norepinephrine, cyclic-AMP-mediated vasodilation i.e. isoproterenol and also sympathetically mediated vascular tone i.e. phentolamine wherein adenosine was used as a control vasodilator. Next, blood samples were collected both before and after an hour after the study of drug administration was done. This was also done at the end of intrabrachial infusions for measuring plasma norepinephrine levels of concentration. After the placebo and the administration of Viagra, the results for forearm vascular responses towards norepinephrine, isoproterenol and adenosine were all noticed as not being any different. However the percentage level in forearm vascular resistance for phentolamine was very much low after the placebo and after the administration of Viagra. Sildenafil in Viagra was known to increase the plasma norepinephrine levels significantly when compared with placebo after 60 minutes of study of drug administration. Thus it was found that Viagra increased sympathetically mediated vascular tone in healthy men who were in their middle age.