AO Eweka, AB Eweka
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 centers, namely the superior colliculus (SC) of the adult Wistar rat, was carefully studied. Rats of both sexes (n=24), with an average weight of 202 g, were randomly divided into three treatment (n=18) and control (n=6) groups. Rats in treatment groups "A", "B" and "C" were administered 0.25 mg/kg, 0.70 mg/kg and 1.43 mg/kg of basal body weight of sildenafil citrate dissolved in distilled water daily for 30 days, respectively, through orogastric feeding tube, while that of control group D was administered an equal volume of distilled water daily during the experimental period. The rats were fed with culture mash obtained from Edo Feeds and Flour Mill Ltd, Ewu, Edo State, Nigeria and provided with ample water. The rats were sacrificed on the thirty-first day of the experiment. The superior colliculus was carefully dissected and rapidly fixed in 10% formal saline for histological studies. Histological results after H&E indicated that the treated section of the superior colliculus exhibited variable degree of cellular clustering, cellular hypertrophy and intercellular vacuolations appearing in the stroma of the superior colliculus. Varying dosages and prolonged administration of sildenafil citrate may have deleterious effects on the neurons of the intracranial visual relay center and this may probably have adverse effects on visual sensitivity through its deleterious effects on the superior colliculus cells of adult Wistar rats. It is therefore recommended that further studies be conducted to corroborate these observations.