Min K S, Ohyanagi N, Ohta M, Onosaka S, Tanaka K
Department of Nutrition, Kobe-Gakuin University, Japan.
Toxicol Appl Pharmacol. 1995 Oct;134(2):235-40. doi: 10.1006/taap.1995.1189.
The effects of erythropoiesis on cadmium-metallothionein (Cd-MT)2 levels in spleen, a major erythropoietic tissue, was examined following sc injection of 109CdCl2 into mice. As the concentration of Cd in plasma decreased following injection of 109CdCl2 into control mice, the levels in spleen and liver increased rapidly. After 48 hr, when the concentration of Cd in the erythrocyte (RBC) was at maximum, the level of Cd in the spleen, but not liver, had decreased. These variations of Cd concentration in spleen and RBC were more notable in mice made anemic by phenylhydrazine (PH). Zinc (Zn)-MT was detected in the PH-induced hemopoietic spleen. A subsequent injection of CdCl2 further induced Cd-MT in the spleen. The protein in spleen contained Cd and Zn but not Cu as in RBCs. Maximum levels of Cd-MT in spleen and RBCs of the PH-treated mice were about four times higher than those of control mice. The concentration of Cd-MT in the spleen of polyemia mice, induced by RBC transfusion, was 50% lower than that of control mice. When erythropoietin was injected into the polyemia mice prior to CdCl2, the concentration of Cd-MT in spleen increased about sixfold. These changes in Cd-MT levels in spleen were not observed in either liver or kidney. The effects of erythropoiesis on the concentration of Cd-MT in the spleen corresponded with effects seen in RBC. These results suggest that splenic Cd-MT can be the source of Cd-MT in mature RBC.
在给小鼠皮下注射109CdCl2后，检测了红细胞生成对主要造血组织脾脏中镉 - 金属硫蛋白（Cd - MT）2水平的影响。向对照小鼠注射109CdCl2后，随着血浆中镉浓度降低，脾脏和肝脏中的镉浓度迅速升高。48小时后，当红细胞（RBC）中的镉浓度达到最高时，脾脏中的镉浓度下降，但肝脏中的镉浓度未下降。在苯肼（PH）致贫血小鼠中，脾脏和红细胞中镉浓度的这些变化更为明显。在PH诱导的造血脾脏中检测到锌（Zn） - MT。随后注射CdCl2进一步诱导脾脏中Cd - MT的产生。脾脏中的蛋白质含有镉和锌，但不像红细胞那样含有铜。PH处理小鼠脾脏和红细胞中Cd - MT的最高水平比对照小鼠高约四倍。红细胞输血诱导的多血症小鼠脾脏中Cd - MT的浓度比对照小鼠低50％。在给多血症小鼠注射氯化镉之前注射促红细胞生成素，脾脏中Cd - MT的浓度增加约六倍。在肝脏或肾脏中均未观察到脾脏中Cd - MT水平的这些变化。红细胞生成对脾脏中Cd - MT浓度的影响与在红细胞中观察到的影响一致。这些结果表明，脾脏Cd - MT可能是成熟红细胞中Cd - MT的来源。
