224NEUROHISTOCHEMICAL EVALUATION OF SOME DEHYDROGENASES ACTIVITIES IN SUPERIOR COLLICULUS OF ADULT WISTAR RATS FOLLOWING CHRONIC SIMULTANEOUS ADMINISTRATION OF ETHANOL AND ACETAMINOPHENAcetaminophen is a drug with potent antipyretic and analgesic actions but with very weak anti-inflammatory activity while ethanol is a depressant consumed as a social drug. Both drugs have been implicated with high levels of abuse while the superior colliculus is involved in processing visual related signals. In this study eighty adult wistar rats of average weight 210±4.22g were randomly assigned into four groups of treatments T1,T2T3 and control C (N=20) . The animals were fed on standard laboratory mouse chow with water provided ad libitum. For six weeks, animals in group T1 received 100mg/Kg.bwt. acetaminophen and 25% ethanol in 2% sucrose solution while group T2 animals received 25% ethanol in 2% sucrose solution. T3 animals were given 100mg/Kg.bwt acetaminophen and group C animals were given 2% sucrose solution. All the solutions served as drinking water and were replaced freshly at 16.00 hours GMT daily. All the animals were sacrificed by cervical dislocation and the regions of superior colliculus were dissected and processed for histochemical demonstration of the activities of LDH, SDH and G6PD enzymes. Distorted brains were seen in the treatment groups T1 and T2 with significant (P<0.001) weight loss compared to the control. Reduced sites of formazan deposits in T1 and T2 compared to high fomazan deposits in T3 and control groups were observed. The bioassay revealed significantly reduced (P<0.05) activities of LDH, SDH and G6PD in groups T1 and T2 compared to the control group while insignificantly increased activities were recorded in the Treatment group T3 compared to the control group. The observed brain weight loss including reduced sites of formazan deposits and activities of the enzymes of carbohydrate metabolism investigated is a consequence of long term simultaneous intake of ethanol and acetaminophen which will compromise neuronal energy availability and consequently place an adverse effect the normal functions of the superior colliculus as a visual relay center and most especially in the maintenance of saccade.fakuns@yahoo.comResearch432013Acetaminophen,Ethanol, Fomazan deposits,Vision,EnzymesFakunle P.B,Ajibade A.J,Ajani R.A,Adefule A.KAnatomy Department, Ladoke Akintola University of Technology, Ogbomoso, Oyo-state, Nigeria.,Anatomy Department, Ladoke Akintola University of Technology, Ogbomoso, Oyo-state, Nigeria.,Biochemistry Department, Ladoke Akintola University of Technology, Ogbomoso, Nigeria,Anatomy Department Olabisi Onabanjo University, Ikenne, Ogun-State, Nigeria.