Journal of Life Sciences Research

Lead and cadmium are highly toxic metals that can be ingested or inhaled from a variety of industrial and dietary sources. The purpose of this study was to determine the impact 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 and the protective effect of barley ( Hardeum valgara) plant . Five groups of animals were used in this experiment ,frist group of animals was subcutaneous injected at dose level (30mg/kg. body weight) lead acetate , the second group was injected with (1mg/kg. body weight) cadmium chloride, third group of animals received a mixed dose of the two heavy metals with the same previous dose , the fourth dose was recived an aqueous solution of barley (5mg/kg body weight ) for two weeks followed by a mixed dose of lead and cadmium (30mg/kg. body weight), (1mg/kg.) .Animals were decapitated after two,four,six and eight weeks after injection. 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 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. Supplemented groups with barley exhibited a similar MAO to the control group, suggesting that barly protected the CNS from functional damage resulted from the heavy metales . Accordingly, these results indicate that barley supplementation in amixed dose of lead and cadmium injected pigs normalized MAO in most CNS regions, i.e is lead to a general improvement in MAO activity .