acute effect of diazinon on lipid peroxidation level and activities of antioxidant enzymes in rat spleen

background: diazinon (dzn) is one of the most organophosphates (ops) insecticides that widely used in agriculture and industry. some ops are capable to produce free radicals and induce malfunction in body antioxidant systems. enzymatic and nonenzymatic antioxidants such as superoxide dismutase (sod), catalase (cat) and glutathione s-transferase (gst) and glutathione (gsh) normally counteract damaging effects of free radicals. the aim of this study was to evaluate the effects of dzn on spleen antioxidant system in male rat. methods: wistar male rats were randomly divided into four groups including: control group receiving corn oil as dzn solvent and three experimental groups receiving of different doses dzn (30, 50 and 100 mg/kg) by intraperitoneal injection. 24 hours after injection, animals were anesthetized and spleen tissue removed. after hemogenizing, sod, cat, gst and lactate dehydrogenase (ldh) activities as well as gsh and malondialdehyde (mda) levels were determined by biochemical methods. results: at doses level higher than 30 mg/kg dzn, sod and gst activities were significantly increased, while cat activity and gsh level were significantly decreased, when compared with the control. conclusion: dzn induces the production of free radicals and oxidative stress in a dose- dependent manner. the alteration of antioxidant enzyme activities in spleen may result from increased detoxification capacity. depletion of gsh can impair the cell’s defense against the toxic actions of free radicals and indicative of oxidative tissue injury.