title: Role of intestinal metallothionein in absorption and distribution of orally administered cadmium.
abstract: The effects of mucosal metallothionein (MT) preinduced by Zn on the intestinal absorption and tissue distribution of Cd were studied. 109CdCl2 was administered to control and Zn-pretreated rats. The total amount of Cd distributed to the liver and the kidney in the group pretreated with 100 mg/kg of Zn was about 70% that of the control group. In the control group, the Cd concentration in the intestinal mucosa reached a maximum 16-24 hr after its administration and then gradually decreased with time, unlike that in the liver and the kidney. The concentration of intestinal Cd in the pretreated group reached a maximum earlier than it did in the control group and most of the Cd was in the MT fraction. Pretreatment with Zn (100 mg/kg or higher, po) caused a reduction in the Cd concentration in the liver and an increase in the kidney. Pretreatment with Zn (5 X 10 mg/kg, sc) or Cd (5 mg/kg, po) also increased renal Cd concentration. This was effective at 24 hr but not at 0.5 hr after pretreatment. These effects of pretreatment with Zn (100 mg/kg, po) on tissue distribution of Cd were also observed after an intraintestinal injection of Cd but not after an iv injection. The results indicate that MT in intestinal mucosa plays a significant role not only in the absorption of Cd but also in its transport to the kidney.
authors.affiliation: Department of Nutrition, Kobe-Gakuin University, Japan.
authors.forename: K S
authors.initials: KS
authors.lastname: Min
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita
authors.forename: S
authors.initials: S
authors.lastname: Onosaka
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002104:Cadmium / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007267:Injections; D007275:Injections, Intravenous; D007408:Intestinal Absorption / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014018:Tissue Distribution; D015032:Zinc / Q000494:pharmacology
chemical_list: D002104:Cadmium; D008668:Metallothionein; D015032:Zinc