title: Increased nephrotoxicity after combined administration of melamine and cyanuric Acid in rats.
abstract: Renal toxicity by melamine in combination with cyanuric acid (1:1) was investigated. Male rats were orally administered melamine plus cyanuric acid (5, 50 or 400 mg/kg each) for 3 days. In contrast to a negligible effect by melamine alone (50 mg/kg, a no-observed-adverse-effect-level: NOAEL), co-administration with cyanuric acid markedly increased the concentrations of blood urea nitrogen and creatinine, as well as kidney weight. A high dose (400 mg/kg) of melamine plus cyanuric acid induced more severe kidney toxicity. The increased blood parameters for kidney toxicity and organ weight lasted longer than 4 days. Combined treatment with melamine and cyanuric acid (50-400 mg/kg each) resulted in many gold-brown crystals and toxic lesions in renal tubules, which were not observed in animals treated with melamine alone (50 mg/kg). These results indicate that only a 3-day exposure to melamine in combination with cyanuric acid causes severe renal damage, even at a NOAEL for melamine found in a 13-week toxicity study. Therefore, it is suggested that the tolerable daily intake or regulatory/management levels of melamine need to be re-considered for cases of co-exposure with cyanuric acid.
authors.affiliation: College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea.
authors.forename: Dongsun
authors.initials: D
authors.lastname: Park
authors.forename: Tae Kyun
authors.initials: TK
authors.lastname: Kim
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Dae-Kwon
authors.initials: DK
authors.lastname: Bae
authors.forename: Goeun
authors.initials: G
authors.lastname: Yang
authors.forename: Yun-Hui
authors.initials: YH
authors.lastname: Yang
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Joo
authors.forename: Ehn-Kyoung
authors.initials: EK
authors.lastname: Choi
authors.forename: Byeongwoo
authors.initials: B
authors.lastname: Ahn
authors.forename: Jong-Choon
authors.initials: JC
authors.lastname: Kim
authors.forename: Kil-Soo
authors.initials: KS
authors.lastname: Kim
authors.forename: Yun-Bae
authors.initials: YB
authors.lastname: Kim