Some histological effects of chronic administration of chloroquine on the medial geniculate body of adult wistar rat

Abstract

Some histological effects of chronic administration of chloroquine commonly used for prophylaxis or treatment of malaria, rheumatoid arthritis and lupus erythematosus on the medial geniculate body (MGB) of adult wistar rats was carefully studied. T h e rats of both sexes (n= 18); average weight of 184g were randomly assigned into treatment (11= 10) a nd control (n=7) groups. The rats in the treatment group received 2mg/kg body weight of chloroquine base dissolved in distilled water daily for fourteen days through the orogastric tube administration while the control rats received equal volume of distilled water daily through the same route. The rats were fed with rat pellets purchased from Topfeed Ltd. Sapele. Delta State. Nigeria and given water liberally and were then sacrificed on day fifteen of the experiment. T h e MGB were carefully dissected out and quickly fixed in 10% formal saline for routine histological stud)' after H & E and thionin methods. The histological findings after H & E methods indicated that the treated sections of the MGB showed faintly reduced nuclei size, with the presence of many autophagic vacuoles and degenerative neurons when compared to the control sections. On the other hand, the thionin method indicated that the treated sections 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 with some vacuolations. These findings indicated that chronic administration of chloroquine has a deleterious effect on the neurons and nissl substance of the MGB. Chloroquine may probably have adverse effects on auditor}' sensibilities by its deleterious cffects on the nerve cells and nissl substances of the MGB of the adult wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out