Biomaterial Database

Potassium bromate enhances N-ethyl-N-hydroxyethylnitrosamine-induced kidney carcinogenesis only at high doses in Wistar rats: indication of the existence of an enhancement threshold. 2009

Min Wei, and Al-Salmy Hamoud, and Takashi Yamaguchi, and Anna Kakehashi, and Keiichirou Morimura, and Kenichiro Doi, and Masahiko Kushida, and Mitsuaki Kitano, and Hideki Wanibuchi, and Shoji Fukushima

Department of Pathology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.

As susceptibility to carcinogens varies considerably among different strains of experimental animals, evaluation of dose-response relationships for genotoxic carcinogen in different strains is indispensable for risk assessment. Potassium bromate (KBrO(3)) is a genotoxic carcinogen inducing kidney cancers at high doses in male F344 rats, but little is known about its carcinogenic effects in other strains of rats. The purpose of the present study was to determine dose-response relationships for carcinogenic effects of KBrO(3) on N-ethyl-N-hydroxyethylnitrosamine (EHEN)-induced kidney carcinogenesis in male Wistar rats. We found that KBrO(3) showed significant enhancement effects on EHEN-induced kidney carcinogenesis at above 250 ppm but not at doses of 125 ppm and below when evaluated in terms of induction of either preneoplastic lesions or tumors in male Wistar rats. Furthermore, KBrO(3) significantly increased the formation of oxidative DNA damage at doses of 125 and above but not at doses of 30 ppm and below in kidneys. These results demonstrated that low doses of KBrO(3) exert no effects on development of EHEN-initiated kidney lesions and induction of oxidative DNA damage. Taking account of previous similar findings in male F344 rats, it is strongly suggested that a threshold dose exists for enhancement effects of KBrO(3) on kidney carcinogenesis in rats.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D007680	Kidney Neoplasms	Tumors or cancers of the KIDNEY.	Cancer of Kidney,Kidney Cancer,Renal Cancer,Cancer of the Kidney,Neoplasms, Kidney,Renal Neoplasms,Cancer, Kidney,Cancer, Renal,Cancers, Kidney,Cancers, Renal,Kidney Cancers,Kidney Neoplasm,Neoplasm, Kidney,Neoplasm, Renal,Neoplasms, Renal,Renal Cancers,Renal Neoplasm
D008297	Male		Males
D009929	Organ Size	The measurement of an organ in volume, mass, or heaviness.	Organ Volume,Organ Weight,Size, Organ,Weight, Organ
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D001959	Bromates	Negative ions or salts derived from bromic acid, HBrO3.	Bromate
D002273	Carcinogens	Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.	Carcinogen,Oncogen,Oncogens,Tumor Initiator,Tumor Initiators,Tumor Promoter,Tumor Promoters,Initiator, Tumor,Initiators, Tumor,Promoter, Tumor,Promoters, Tumor
D003849	Deoxyguanosine	A nucleoside consisting of the base guanine and the sugar deoxyribose.
D004052	Diethylnitrosamine	A nitrosamine derivative with alkylating, carcinogenic, and mutagenic properties.	Nitrosodiethylamine,N-Nitrosodiethylamine,N Nitrosodiethylamine
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries