ABSTRACT
The present study was undertaken to investigate the effect of chronic administration of lead and cadmium on the activity of monoamine oxidase [MAO] in different central nervous system regions [CNS] of male guinea pigs. Lead and cadmium was intraperitoneally injected at dose level [30 mg/kg. body weight]and[1 mg/kg.] respectively as lead acetate and cadmium chloride daily for, two, four, six and eight weeks. The activity of monoamine oxidase [MAO] was determined in the cerebral cortex, caudate putamen, thalamus, hypothalamus, superior colliculus, inferior colliculus cerebellum, pons, medulla and spinal cord in male guinea pig CNS. Lead and cadmium induced a general variable changes in the level of the membrane bound enzyme [MAO] in most CNS regions and in turn affecting both cholinergic and adrenergic neurotransmitters. These results suggest that lead and cadmium may exerts neurotoxic effect by altering certain membrane bound enzymes and may cause oxidative stress that could lead to neurodegenerative diseases