镍对大鼠脑组织一氧化氮、一氧化氮合酶的影响

Effects of nickel sulfate on nit ric oxide and nitric oxide synthase in brain tissues of rats

给大鼠腹腔注射染毒硫酸镍 1 2 5mg/kg、 2 5mg/kg、 5 0mg/kg ,每日 1次 ,连续 2周。用原子吸收分光光度法检测脑组织中Ni含量 ;酶法检测脑组织中一氧化氮 (NO)含量和一氧化氮合酶 (NOS)活性。结果显示硫酸镍腹腔注射染毒后脑组织中镍含量显著增多 ,使一氧化氮合酶 (NOS)活性增强的同时引起一氧化氮 (NO)含量的升高。提示镍可透过血脑屏障进入脑组织 ,引起一氧化氮 (NO)过量合成而致中枢神经损伤。

Nickel sulfate was inje cted int raperitoneally for normal Wistar rats wi th sexual maturation at varied doses of 1.25 mg/kg,2.50 mg/kg and 5.00 mg/kg dai ly for two weeks.Brain homogenate of the rats was prepared.Content of nickel in brain tissues was assessed with atomic a bsorption spectrophotometry,and activity of nitric oxide synthase(NOS)and conten t of nitric oxide(NO)were examined by en zyme assay.Results showed that contents of nickel and NO in the brain tissues in creased and activity of NOS boosted up s ignificantly in the rats exposed to nick el sulfate.All these indicate that exces sive exposure to nickel sulfate,which ca n permeate through the bloodbrain barri er and accumulate in the brain tissues,c an cause oversynthesis of NO and increa se activity of NOS in the brain tissues of the rats so as to damage their centra l nervous system.