유리 게르마늄의 투여가 카드뮴 및 수은에 중독된 흰쥐 간장 및 신장조직의 metallothionein 형성에 미치는 영향

Effects of Organic Germanium on Metallothionein Induction in Liver and Kidney of Cadmium and Mercury Intoxicated Rats

This study was initiated to investigate the effects of organic germanium on cadmium and mercury intoxication. The effect was determined by the metallothionein induction in liver and kidney. Male rats (Sprague-Dawley) were treated with CdCl2 (2mg/kg), HgCl2 (1mg/kg) and organic germanium (GE-132) (100mg/kg) in single and in combination via intraperitoneal injection or intragastric administration every other days for 17 days. Experimental animals were sacrificed after 7, 12 and 17 days treatment. The serum transaminase activities (SGOT, SGPT), concentration of metal and metallothionein, metal-binding capacity of metallothionein in liver and kidney were determined and pathomorphological observations were undertaken. The combined treatment of GE-132 and CdCl>2 significantly decreased the increment of serum transaminase activities in rats treated with CdCl2 only, but the combined treatment of GE-132 and HgCl2 did not affect to activities of transaminases induced by mercury only. The concentration of metals (Cd and Hg) except Ge in the liver and kidney of rats increased with the time of treatment. Mercury concentration in kidney of rat treated with HgCl2 only was significantly higher than the combined treatment of GE-132 and HgCl2. The combined treatment of GE-132 and CdCl2 significantly increased the concentration of metallothionein in liver compared to the CdCl2 only, although the concentration of cadmium in liver were not significantly different between two groups. This indicates that GE-132 decreased toxicity of cadmium in liver by promoting metallothionein induction. There were no significant differences in metallothionein concentration in liver and kidney of rats between the combined treatment of GE-132 and HgCl2 and HgCl2 only. Metal-binding capacity of metallothionein varied with each time intervals in liver and kidney of metals treated rats except the liver of the combined treatment of GE-132 and CdCl2. This finding explains the concentration of metallothionein in liver keeps abreast with the concentration of metal. Furthermore, the combined treatment of GE-132 and CdCl2 revealed pathologically less changes in liver tissue than CdCl2 only; the damages of liver cell, such as lobular necrosis and portal inflammation, were relieved and appeared more later. From the above results, organic germanium is considered to have some beneficial effect on the protection of liver from the cadmium intoxication.