Chone Y, Kinouchi T, Yamada T, Suzuki Y, Kitaura K, Jiao Z, Minami T, Bando Y, Uehara H, Mochizuki M, Ohnishi Y, Izumi K. Low susceptibility of Long-Evans Cinnamon rats to N-butyl-N-(4-hydroxybutyl)-nitrosamine-induced urinary bladder carcinogenesis and inhibitory effect of urinary copper.
Jpn J Cancer Res 2000;
91:16-24. [PMID:
10744040 PMCID:
PMC5926224 DOI:
10.1111/j.1349-7006.2000.tb00855.x]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We studied the susceptibilities to N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced urinary bladder carcinogenesis of male Long-Evans Cinnamon (LEC), F344 and Long-Evans Agouti (LEA) rats. Male rats (n=21) were given 0.1% BBN in their drinking water from week 6, 8 and 10 for one week, and killed in week 56. The incidences of transitional cell tumors (papillomas plus carcinomas) in BBN-treated LEC and F344 rats were 12% and 76%, respectively (P<0.001, experiment 1), and those in LEC and LEA rats were 11% and 95%, respectively (P<0.001, experiment 2). When male LEC and F344 rats were given 0.1% BBN in their drinking water for 7 days, the intake of BBN and the urinary concentration of its active metabolite, N-butyl-N-(3-carboxypropyl)nitrosamine (BCPN), were higher in the LEC rats (P<0.01). The urinary pHs of untreated LEC and F344 rats were similar between week 6 and 30. The urinary copper concentration was lower in LEC rats before jaundice than in F344 rats, but its concentrations in 28- and 50-week-old LEC rats were 1.7 and 2.3 times those in F344 rats. In a two-stage carcinogenesis study using F344 rats, i.p. injections of cupric nitrilotriacetate increased urinary copper excretion, and inhibited BBN-induced bladder carcinogenesis. In a two-stage carcinogenesis study using LEC rats, oral administration of D-penicillamine decreased urinary copper excretion, and increased BBN-induced bladder cancer, although the difference was not significant. These data show that LEC rats are resistant to bladder carcinogenesis and suggest that urinary copper has a significant role in their resistance.
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