Histological studies of the effects of chronic administration of chloroquine on the inferior colliculus of the adult wistar rat

The effects of chronic administration of chloroquine commonly used for prophylaxis or treatment of malaria, rheumatoid arthritis and lupus erythematosis on the inferior colliculus (IC) of adult male and female wistar rats was studied. Seventeen rats of average weight 184g were randomly assigned into treatment (n = 10) and control (n = 7) groups. Rats in the treatment group received 2mg/kg body weight of chloroquine phosphate dissolved in distilled water daily for 14 days. The control rats received equal volume of distilled water daily. The rats were fed with rat pellets purchased from Ladokun Feeds Limited, Ibadan, Nigeria and given water liberally. They were then sacrificed on day fifteen of the experiment. The inferior colliculus was carefully dissected out and quickly fixed in 10% formal saline for histological study. Findings indicate that rat in the treated group showed degenerative changes, vacuolations and reduced cellular population in the inferior colliculus. Chronic administration of chloroquine has adverse effect on the micro-anatomy of the inferior colliculus in rats. Chloroquine may have adverse effects on the auditory sensibilities by affecting the micro-anatomy of the inferior colliculus of the adult wistar rats. We recommended further studies aimed at corroborating these observations.