title: Zinc-induced tolerance to cadmium cytotoxicity without metallothionein induction in cultured bovine aortic endothelial cells.
abstract: We investigated the cytotoxicity of cadmium in cultured vascular endothelial cells from bovine aorta pretreated with zinc. The cytotoxicity was evaluated by the [3H]adenine release assay. It was shown that the increase in the [3H]adenine release after challenge with cadmium was significantly prevented by pretreatment with zinc. It was histologically observed that cadmium-induced occurrence of the de-endothelialized areas was reduced in zinc-pretreated cell layer. Intracellular accumulation of cadmium was significantly less but that of zinc was more in zinc-pretreated cells. The content of cadmium in both the particulate and the cytosol fraction was decreased by zinc pretreatment; however, metallothionein content after challenge with cadmium was not changed. It was therefore concluded that zinc is capable of inducing a tolerance to cadmium cytotoxicity in cultured vascular endothelial cells; this tolerance is postulated to be due to a decrease in the intracellular cadmium accumulation rather than a metallothionein induction.
authors.affiliation: Department of Environmental Science, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Mishima
authors.forename: T
authors.initials: T
authors.lastname: Kaji
authors.forename: C
authors.initials: C
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Sakamoto
authors.forename: H
authors.initials: H
authors.lastname: Kozuka
mesh_terms: D000225:Adenine / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects; D002104:Cadmium / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000633:toxicity*; D002417:Cattle; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008668:Metallothionein / Q000096:biosynthesis*; D015032:Zinc / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D002104:Cadmium; D008668:Metallothionein; D015032:Zinc; D000225:Adenine