This study examined changes in the levels of free polyamines [Putrescine (Pu) and Spermidine (Sd)] and acetylpolyamine [acetylputrescine (Ac-Pu), N1-acetylspermidine (N1-Ac-Sd) and N8-acetylspermidine (N8-Ac-Sd)] in urine and in free polyamines [Pu, Sd and Spermine (Sm)] in erythrocytes on inhibition of DMBA-induced oral tumorigenesis by topical beta-carotene. Group 1 was treated with DMBA and beta-carotene, group 2 was treated with DMBA alone, and group 3 was treated with beta-carotene alone. Values of urinary Ac-Pu and N8-Ac-Sd in group 1 were elevated significantly at 7.5 weeks when no macroscopical tumor was observed, but Pu, Sd, N1-Ac-Sd and the ratio of N1-Ac-Sd to N8-Ac-Sd did not differ significantly from that of group 3. At 12.5 weeks, tumor incidence in group 1 (50%) was significantly lower than that in group 2 (100%). Urinary levels of Pu, Sd, Ac-Pu, N1-Ac-Sd and N8-Ac-Sd in group 2 were significantly higher than those in group 3. In contrast, the level of urinary polyamines in group 1 was significantly lower than that in group 2. Similar to urinary polyamines, Sm, Sd and Pu values in erythrocytes elevated significantly in the animals treated with DMBA alone, but the values of Sm and Sd in erythrocytes only increased slightly in animals treated with DMBA and beta-carotene. Erythrocyte polyamine levels in animals with malignant tumor were significantly higher than those in animals with benign tumor. We conclude that beta-carotene reduced both the development of tumor and urinary polyamine and erythrocyte polyamine levels.
|出版ステータス||Published - 1990|
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