Effects of zinc deficiency on pre-existing cadmium-metallothionein in the pancreas.
Although the injection of cadmium salts increases the metallothionein (MT) concentration in a number of organs, including pancreas, the induced synthesis of pancreatic metallothionein was specifically decreased in zinc deficiency. The fate of Cd-induced metallothionein and the change in tissue distribution of Zn and Cd were studied with the onset of Zn deficiency. Rats were repeatedly injected with CdCl2 to induce MT synthesis, and were subsequently made Zn deficient. The lability of the pancreatic Zn pool, as compared with that of liver and kidney, was demonstrated. During Zn deficiency, there was little change in Cd concentration or MT level in either liver or kidney. When Zn deficiency led to a decrease in pre-existing pancreatic MT, Cd was not eliminated from the pancreas, but was transferred to a high molecular weight fraction. On the basis of these results we suggest that the presence of Cd-Zn-MT has little effect on the eventual pancreatic Zn and MT contents, during subsequent Zn deficiency.
D000818:Animals; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D008668:Metallothionein / Q000096:biosynthesis*; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution; D015032:Zinc / Q000172:deficiency* / Q000378:metabolism
D002104:Cadmium; D008668:Metallothionein; D015032:Zinc