Effects Of Subacute Administration Of Chloroquine On The Nissl Substance Of The Inferior Colliculus Of Adult Wistar Rats

The effects of subacute administration of chloroquine commonly used for prophylaxis or treatment of malaria, rheumatoid arthritis and lupus erythematosis on the inferior colliculus (IC) of adult wistar rats was studied. The rats of both sexes (n=17), average weight of 184g were randomly assigned into treatment (n=10) and control (n=7) groups. The rats in the treatment group received 2mg/kg body weight of chloroquine phosphate dissolved in distilled water daily for fourteen days. The control rats received equal volume of distilled water daily. The rats were fed with rat pellets and given water liberally and 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. Histological findings of the nissl substance indicate that the treatment groups showed sparsely distributed neurons, which stain less intensely when compared with the control. The nissl substance in some of the neurons appeared degenerative while some hypertrophied. These findings indicate that chronic administration of chloroquine has a deleterious effect on the nissl substance of the inferior colliculus. Chloroquine may have adverse effects on auditory sensibilities by its deleterious effects on the nissl substance of the inferior colliculus of the adult wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out. Keywords : Chloroquine, nissl substance, inferior colliculus and wistar rats. Annals of Biomedical Science Vol.3 (1&2) 2004: pp. 33-38