The Effects of Sildenafil Citrate (Viagra) in the Early Phase of Healing Process in Open Wounds in Dogs

Abstract

In vivo (n = 16) and in vitro (n = 16) experiments were conducted in dogs to describe the effects of sildenafil citrate (viagra) on histopathological changes during the healing process with respect to angiogenesis and compare vasodilatative effects of sildenafil citrate, acetylcholine and sodium nitroprusside. General anaesthesia was performed with 0.2% ketamine HCl by intravenous drip after premedication with xylazine (5 mg.kg(-1)) and atropine sulphate (0.05 mg.kg(-1)). Round open wounds were created in all skin layers on anterior brachial region in all animals. On days 1, 3, 5 and 7 following the operation sildenafil citrate (25 mg) (n = 8) and saline (n = 8) were orally administered. Wound tissues were dissected for histological observation on days 3, 6, and 9. Animals receiving sildenafil citrate had greater granulosa tissue more apparent capillary network and greather fibroblast proliferation than control group on day 6. Vasorelaxant effects of sildenafil citrate, acetylcholine and sodium nitroprusside on a. brachialis were investigated in vitro. In this study, relative vasorelaxant effects of sildenafil citrate, acetylcholine and sodium nitroprusside were 4.91, 5.75 and 6.70, respectively. Results of this study suggest that sildenafil citrate does enhance the healing process by stimulating angiogenesis.