title: High-dose dietary zinc promotes prostate intraepithelial neoplasia in a murine tumor induction model.
abstract: To evaluate the role of high-dose dietary zinc in the process of prostate malignancy, 60 Sprague-Dawley rats were randomly divided into four groups: tumor induction with carcinogen and hormone (group 1), oral zinc administration without tumor induction (group 2), oral zinc administration with tumor induction (group 3) and a control without zinc administration or tumor induction (group 4). Zinc was supplied orally in the form of zinc sulfate heptahydrate dissolved in drinking water to groups 2 and 3 for 20 weeks. Although the serum level of zinc measured at 20 weeks was maintained similarly in each group (P = 0.082), intraprostatic zinc concentrations were statistically different. Group 1 prostates contained the least amount of zinc in both the dorsolateral and ventral lobes at levels of 36.3 and 4.8 microg g(-1), respectively. However, in group 3, zinc levels increased in both lobes to 59.3 and 12.1 microg g(-1), respectively, comparable with that of group 4 (54.5 +/- 14.6 and 14.1 +/- 2.4 microg g(-1)). In spite of these increases in zinc concentration, the prevalence of prostate intraepithelial neoplasm was rather increased in group 3 (53.3% and 46.7%) compared with group 1 (33.3% and 33.3%) in both dorsolateral and ventral prostate lobes. Although prostate intraepithelial neoplasm did not develop in any prostate in group 4, zinc administration did induce prostate intraepithelial neoplasm in group 2 (46.7% and 40.0%). Thus, although high dietary zinc increased intraprostatic zinc concentrations, it promoted, instead of preventing, prostate intraepithelial neoplasm in a murine prostate malignancy induction model.
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Korea.
authors.forename: Young Hwii
authors.initials: YH
authors.lastname: Ko
authors.forename: Yu Jeong
authors.initials: YJ
authors.lastname: Woo
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Hoon
authors.initials: H
authors.lastname: Choi
authors.forename: Seok Ho
authors.initials: SH
authors.lastname: Kang
authors.forename: Jeong Gu
authors.initials: JG
authors.lastname: Lee
authors.forename: Je Jong
authors.initials: JJ
authors.lastname: Kim
authors.forename: Hong Seok
authors.initials: HS
authors.lastname: Park
authors.forename: Jun
authors.initials: J
authors.lastname: Cheon
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D019048:Prostatic Intraepithelial Neoplasia / Q000139:chemically induced* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism
chemical_list: D015032:Zinc