灌胃染镉对大鼠体内某些酶的影响及镉的器官分布

Effect of Cadmium Chloride Administration by Oral Intubation on the Activities of Enzymes and Distribution of Cadmium in Organs of Female Rats

30只成年雌性 SD大鼠 ,等分为 5组 , 至 组灌胃饮服分别含 0、0 .2、1.0、2 .0 mg镉 (Cd)的氯化镉溶液 1m L/只 ,每日 1次 ,持续 10 d; 组灌镉剂量与 组相同 ,持续时间为 30 d。结果发现 ,染镉组 ( ～ 组 ) :血浆丙氨酸氨基转移酶 (AL T)和精氨酸酶 (ARG)活力明显升高 (P<0 .0 5 ) ,但 AL T活力升高剂量 -效应关系不规律 ;肝匀浆 AL T活力明显下降 (P<0 .0 5或 P<0 .0 1) ;全血谷胱甘肽过氧化物酶 (GSH- Px)活力显著下降 (P<0 .0 5 ) ,肝匀浆中 GSH- Px的活力也下降 ;心、肝、肾中 Cd的含量均明显增加 ,蓄积量与灌服剂量呈正相关 (r值分别是 0 .9384、0 .96 87和0 .9379)。 组和 组比较 ,随时间延长 ,心、肝、肾中 Cd蓄积量均明显增加 ,且肾较肝增加更显著。结论认为 ,灌胃染镉对大鼠的生长有障碍作用 ,镉可以明显地抑制 GSH- Px的活力 ,降低机体组织的抗氧化能力 ,引起肝等实质细胞的损伤 ;血浆 ARG的活力可以作为哺乳动物急性镉暴露的一个辅助性监测指标 ;由于损伤性泄漏和直接的抑制同时存在 ,以血浆中 AL T的活力来评价镉对实质器官的损害应十分慎重。

Thirty adult female SD rats were allocated into five groups of six each.Four groups(from Ⅰ to Ⅳ) were intubated orally with 1 mL of solutions contained Cd 0,0.2,1.0,2.0 mg as cadmium chloride,respectively once daily for 10 d.Group Ⅴ were given the same dose Cd as group Ⅳ for 30 d.The results showed that the activities of ALT and ARG in the plasma of rats exposed to cadmium significantly increased(P<0.05) compared with that of control,but there was no regular dose-effect relationship of ALT activity;The activity of ALT in hepatic homogenate decreased significantly(P<0.05,or P<0.01);The activity of GSH-Px in whole blood significantly decreased(P<0.05),and so did in their hepatic homogenate.The concentrations of cadmium accumulated in heart,liver and kidney obviously increased with dosing,and there was the positive correlation between cadmium levels accumulated and the dose given(r= 0.938 4, 0.968 7, 0.937 9,respectively);The concentration of cadmium in heart,liver and kidney of group Ⅴ was higher than group Ⅳ,and the increased rate of cadmium accumulated in the kidney was faster than that in the liver.It was concluded that cadmium chloride administration may retard the growth of rats.Cadmium may significantly inhibit the activity of GSH-Px,reduce the ability of anti-oxidation in tissues and induce injury of parenchymal cells such as liver.ARG activity in plasma may be considered as a comonitory index of cadmium in acute cadmium exposed animals.It should be taken care when the activity of ALT in the plasma is used as a characteristic to monitor parenchymal organs injury induced by cadmium.