The effects of sildenafil citrate on the superior colliculus of adult Wistar rats (Rattus norvegicus) - a histological study

The histological effect of oral administration of sildenafil citrate (Viagra), commonly used as an aphrodisiac and for the treatment of erectile dysfunction on one of the visual relay centres namely the superior colliculus (SC) of adult Wistar rat was carefully studied. The rats of both sexes (n=24), average weight of 202g were randomly assigned into three treatment (n=18) and control (n=6) groups. The rats in the treatment groups ‘A’, ‘B’ and ‘C’ received respectively, 0.25mg/kg, 0.70mg/kg and 1.43mg/kg body weight of sildenafil citrate base dissolved in distilled water daily for 30 days, through orogastric feeding tube, while that of the control group D, received equal volume of distilled water daily during the period of the experiment. The rats were fed with growers’ mash obtained from Edo Feeds and Flour Mill Ltd, Ewu, Edo State, Nigeria and were given water liberally. The rats were sacrificed on day thirty-one of the experiment. The Superior colliculus was carefully dissected out and quickly fixed in 10% formal saline for histological studies. The histological findings after H&E method indicated that the treated section of the Superior colliculus showed some varying degree of cell clustering, cellular hypertrophy, and intercellular vacuolations appearing in the stroma of the superior colliculus. Varying dosage and long administration of sildenafil citrate may have some deleterious effects on the neurons of the intracranial visual relay centre and this may probably have some adverse effects on visual sensibilities by its deleterious effects on the cells of the superior colliculus of adult Wistar rats. It is therefore recommended that further studies aimed at corroborating these observations be carried out.