Power Doppler ultrasonography of blood flow and electroretinography and histomorphometry retinal eye in rabbits treated with different doses of sildenafil citrate

• Grant number: 11/08728-8
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2011
• End date: June 30, 2012
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: José Luiz Laus
• Grantee: José Luiz Laus
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Inhibitors of phosphodiesterase type-5, originally developed as antianginal, can inhibit the hydrolysis of cGMP in the corpus cavernosum by increasing the concentration of this second messenger in smooth wall of the vessel. The event action results in increased intravascular nitric oxide (NO), promoting vasodilation at the site. However, PDE-5 inhibitors may also act by inhibiting phosphodiesterase type-6 (PDE-6) in the retina, prompting ophthalmologic abnormalities, among which the increase in retrobulbar circulation, vasodilation and peripapillary changes of visual acuity. Studies on sildenafil have been more directed to the side effects on vision that entails. It is assumed that the activity of vasoactive on the retina may represent a therapeutic benefit, especially in patients with retinal ischemia due to chronic hypertensive situations. Considering how feasible the hypothesis proposed to investigate the effects of sildenafil in different doses, on retinal and retrobulbar circulation in healthy rabbits, availing himself, for this, Doppler ultrasonography, electroretinography and retinal histomorphometry, a Since angiography is already being done by the same team. (AU)