出版社：Korean Society of Environmental Health and Toxicology
摘要：Zinc (Zn) is an essential element in biological process. however inadequate Zn status in general population have been recognized. To update the knowledge for Zn-cadmium (Cd) interaction,we studied the intestinal uptake and transport,and the expression of metal transporter proteins (divalent metal transporter I,DMTI: metal transporter protein I,MTPI;zinc transporter 1. ZnTI;metallothionein 1,MT1) in duodenum after Cd exposure using Zn deficient animal model. Rats were fed Zn deficient (ZnD,0.5~ 1.0 mg Zn/kg) or Zn supplemented (ZnS.50 mg Zn/kg) diet for 4 weeks. and fllowed single administration of "CdCl2 oally. The body Zn status and tissue Cd concentration were determined at 24 hrs after Cd administration. Total body burden of Cd and Cd absorption index (AI,%) were estimated based on the tissue Cd analyzed. DMTI,MTPI, ZnTI and MTI mRNA were analyzed by using RT- PCR method. Feeding of Zn deficient diet for 4 weeks produced a reduced body weight gain and a depletion of body Zn. Tissue Cd concentration,body burden of Cd and Cd absorption index were higher in the ZnD diet fed rats than the ZnS diet fed rats. Especially,Cd concentration in the small intestine (duodenum,jejunum and ileum) and the colon of FeD diet fed rats were higher markedly than in the FeS diet group. The expression levels of DMTI,MTPI and ZnTI mRNA in FeD diet fed rats were similar to the FeS diet. The level of MTI mRNA expression was significantly lower in the FeD than the FeS diet fed rats. Taken together,theses results indicate that Zn deficiency in diet induce an increased intestinal absorption and tissue retention of Cd,and down - regulate the MTI expression in the intestine which might be play a part of role in Cd absorption and transport in mammalian. These findings suggest that deficiency of essential metal could be enhanced the toxicity of toxic,non -essstial metals through the metal- metal interaction.
关键词：zinc (Zn);cadmium (Cd);metallothionein I (MTI). Zn -Cd interaction;tissue Cd concentration
