title: The natural outcome of melamine-induced bladder stones with bladder epithelial hyperplasia after the withdrawal of melamine in mice.
abstract: The natural outcome of melamine-induced bladder stones (cystoliths) with bladder epithelial hyperplasia (BEH) after melamine withdrawn is unclear. Using an ideal dual-model system, three experiments were conducted in BALB/c mice. Each experiment included a control, model 1 and model 2 groups. The mice were fed a regular diet in controls or a 9373 ppm melamine diet in models, and the first day was designated as dosing day 1. The melamine diet was then replaced by the regular diet in the model 2 groups, and the first day was designated as post-dosing day 1. On dosing days 12, 35 and 49, the incidence of cystoliths and diffusely active BEH was 8/8 in the mice of three model 1 groups. On post-dosing days 1, 4 and 8, in the mice of three model 2 groups, the incidence of cystoliths was 2/8, 0/8 and 1/8, respectively, and the progressive regression of BEH was observed. In conclusion, both the stones and BEH have the natural property of rapid development and rapid regression, and melamine withdrawn plays a key role in the stone dissolution-discharge necessary for BEH regression. BEH may be reversible after the discharge of the stones. The conventionally conservative therapy is thus reasonable.
authors.affiliation: Department of Pathology, School of Medicine, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, China.
authors.forename: Shu-Ting
authors.initials: ST
authors.lastname: Ren
authors.forename: Chang-Fu
authors.initials: CF
authors.lastname: Xu
authors.forename: Yun-Xia
authors.initials: YX
authors.lastname: Du
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Gao
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.forename: Yi-Na
authors.initials: YN
authors.lastname: Jiang
mesh_terms: D000818:Animals; D006965:Hyperplasia; D051379:Mice; D008807:Mice, Inbred BALB C; D014227:Triazines / Q000633:toxicity*; D001744:Urinary Bladder Calculi / Q000139:chemically induced* / Q000473:pathology; D019459:Urothelium / Q000187:drug effects* / Q000473:pathology
chemical_list: D014227:Triazines; C011907:melamine