The Experts below are selected from a list of 20553 Experts worldwide ranked by ideXlab platform

Takashi Sugimura - One of the best experts on this subject based on the ideXlab platform.

  • Food derived mutagens and carcinogens
    1992
    Co-Authors: Keiji Wakabayashi, Minako Nagao, Hiroyasu Esumi, Takashi Sugimura
    Abstract:

    Cooked Food contains a variety of mutagenic heterocyclic amines. All the mutagenic heterocyclic amines tested were carcinogenic in rodents when given in the diet at 0.01-0.08%. Most of them induced cancer in the liver and in other organs. It is noteworthy that the most abundant heterocyclic amine in Cooked Food, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, produced colon and mammary carcinomas in rats and lymphomas in mice but no hepatomas in either. 2-Amino-3-methylimidazo[4,5-f]quinoline induced liver cancer in monkeys. Formation of adducts with guanine by heterocyclic amines is presumably involved in their carcinogenesis. Quantification of heterocyclic amines in Cooked Foods and in human urine indicated that humans are continuously exposed to low levels of them in the diet. These low levels of heterocyclic amines are probably insufficient to produce human cancers by themselves. However, a linear relationship between DNA adduct levels and a wide range of doses of a heterocyclic amine was demonstrated in animals. It suggests that even very low doses of heterocyclic amines form DNA adducts and may be implicated in the development of human cancer under conditions in which many other mutagens-carcinogens, tumor promoters, and factors stimulating cancer progression exist.

  • a new colon and mammary carcinogen in Cooked Food 2 amino 1 methyl 6 phenylimidazo 4 5 b pyridine phip
    1991
    Co-Authors: Nobuyuki Ito, Hiroyasu Esumi, Shozo Takayama, Ryohei Hasegawa, Masashi Sano, Seiko Tamano, Takashi Sugimura
    Abstract:

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which is produced during cooking and is mutagenic to bacteria and cultured mammalian cells, was found to induce high incidences of colon and mammary carcinomas in F344 rats when administered at a concentration of 400 p.p.m. in the diet for 52 weeks. Since PhIP is the most abundant of the mutagenic heterocyclic amines in Cooked meat and fish, the compound might be related to malignancies of the colon and breast in humans.

  • Carcinogenicities of heterocyclic amines in Cooked Food
    1991
    Co-Authors: Hiroko Ohgaki, Shozo Takayama, Takashi Sugimura
    Abstract:

    Mutagenic heterocyclic amines in Cooked Foods were carcinogenic to mice, rats and/or monkeys, when they were given orally continuously. The most common target organ was the liver, but in CDF1 mice lung tumors, forestomach tumors, lymphomas/leukemias, and blood vessel tumors in the brown adipose tissues were also induced. In F344 rats, in addition to liver tumors, tumors in the Zymbal gland, skin, clitoral gland, small and large intestines, oral cavity, and mammary gland were also induced. Monkeys given IQ developed metastatic hepatocellular carcinomas.

Hiroyasu Esumi - One of the best experts on this subject based on the ideXlab platform.

  • Food derived mutagens and carcinogens
    1992
    Co-Authors: Keiji Wakabayashi, Minako Nagao, Hiroyasu Esumi, Takashi Sugimura
    Abstract:

    Cooked Food contains a variety of mutagenic heterocyclic amines. All the mutagenic heterocyclic amines tested were carcinogenic in rodents when given in the diet at 0.01-0.08%. Most of them induced cancer in the liver and in other organs. It is noteworthy that the most abundant heterocyclic amine in Cooked Food, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, produced colon and mammary carcinomas in rats and lymphomas in mice but no hepatomas in either. 2-Amino-3-methylimidazo[4,5-f]quinoline induced liver cancer in monkeys. Formation of adducts with guanine by heterocyclic amines is presumably involved in their carcinogenesis. Quantification of heterocyclic amines in Cooked Foods and in human urine indicated that humans are continuously exposed to low levels of them in the diet. These low levels of heterocyclic amines are probably insufficient to produce human cancers by themselves. However, a linear relationship between DNA adduct levels and a wide range of doses of a heterocyclic amine was demonstrated in animals. It suggests that even very low doses of heterocyclic amines form DNA adducts and may be implicated in the development of human cancer under conditions in which many other mutagens-carcinogens, tumor promoters, and factors stimulating cancer progression exist.

  • a new colon and mammary carcinogen in Cooked Food 2 amino 1 methyl 6 phenylimidazo 4 5 b pyridine phip
    1991
    Co-Authors: Nobuyuki Ito, Hiroyasu Esumi, Shozo Takayama, Ryohei Hasegawa, Masashi Sano, Seiko Tamano, Takashi Sugimura
    Abstract:

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which is produced during cooking and is mutagenic to bacteria and cultured mammalian cells, was found to induce high incidences of colon and mammary carcinomas in F344 rats when administered at a concentration of 400 p.p.m. in the diet for 52 weeks. Since PhIP is the most abundant of the mutagenic heterocyclic amines in Cooked meat and fish, the compound might be related to malignancies of the colon and breast in humans.

Thomas Walle - One of the best experts on this subject based on the ideXlab platform.

  • bioactivation of the Cooked Food mutagen n hydroxy 2 amino 1 methyl 6 phenylimidazo 4 5 b pyridine by estrogen sulfotransferase in cultured human mammary epithelial cells
    1998
    Co-Authors: A J Lewis, U K Walle, R S King, F F Kadlubar, C N Falany, Thomas Walle
    Abstract:

    Cooked Food mutagens from fried meat and fish have recently been suggested to contribute to the etiology of breast cancer. Thus, the most prevalent of these compounds, i.e. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, or rather its more mutagenic N-hydroxylated metabolite (N-OH-PhIP), forms DNA adducts in mammary cells, including human mammary epithelial (HME) cells. The objective of this study was to determine the involvement of estrogen sulfotransferase (EST), the only sulfotransferase identified in HME cells, in the further bioactivation of N-OH-PhIP. These studies were done in vitro using human recombinant EST and in intact HME cells. Human recombinant EST increased the covalent binding of [3H]N-OH-PhIP to calf thymus DNA approximately 3.5-fold in the presence of the sulfotransferase co-substrate 3'-phosphoadenosine-5'-phosphosulfate at each N-OH-PhIP concentration (1, 10 and 100 microM) (n = 6, P < 0.001). In contrast, EST did not catalyze the DNA binding of two other Cooked Food mutagens, N-hydroxy-2-amino-3-methylimidazo[4,5-f]quinoline and N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, which are mainly hepatocarcinogens. Cultured HME cells displayed high EST activity, which could be completely inhibited by 1 microM estrone. When the cells were incubated with [3H]N-OH-PhIP, binding to native DNA occurred at 60-240 pmol/mg DNA. This binding was inhibited to 55% of control by 1 microM estrone (P < 0.01, n = 8), suggesting that EST plays a significant role in carcinogen bioactivation in human breast tissue.

Nobuyuki Ito - One of the best experts on this subject based on the ideXlab platform.

  • a new colon and mammary carcinogen in Cooked Food 2 amino 1 methyl 6 phenylimidazo 4 5 b pyridine phip
    1991
    Co-Authors: Nobuyuki Ito, Hiroyasu Esumi, Shozo Takayama, Ryohei Hasegawa, Masashi Sano, Seiko Tamano, Takashi Sugimura
    Abstract:

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which is produced during cooking and is mutagenic to bacteria and cultured mammalian cells, was found to induce high incidences of colon and mammary carcinomas in F344 rats when administered at a concentration of 400 p.p.m. in the diet for 52 weeks. Since PhIP is the most abundant of the mutagenic heterocyclic amines in Cooked meat and fish, the compound might be related to malignancies of the colon and breast in humans.

Shozo Takayama - One of the best experts on this subject based on the ideXlab platform.

  • a new colon and mammary carcinogen in Cooked Food 2 amino 1 methyl 6 phenylimidazo 4 5 b pyridine phip
    1991
    Co-Authors: Nobuyuki Ito, Hiroyasu Esumi, Shozo Takayama, Ryohei Hasegawa, Masashi Sano, Seiko Tamano, Takashi Sugimura
    Abstract:

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which is produced during cooking and is mutagenic to bacteria and cultured mammalian cells, was found to induce high incidences of colon and mammary carcinomas in F344 rats when administered at a concentration of 400 p.p.m. in the diet for 52 weeks. Since PhIP is the most abundant of the mutagenic heterocyclic amines in Cooked meat and fish, the compound might be related to malignancies of the colon and breast in humans.

  • Carcinogenicities of heterocyclic amines in Cooked Food
    1991
    Co-Authors: Hiroko Ohgaki, Shozo Takayama, Takashi Sugimura
    Abstract:

    Mutagenic heterocyclic amines in Cooked Foods were carcinogenic to mice, rats and/or monkeys, when they were given orally continuously. The most common target organ was the liver, but in CDF1 mice lung tumors, forestomach tumors, lymphomas/leukemias, and blood vessel tumors in the brown adipose tissues were also induced. In F344 rats, in addition to liver tumors, tumors in the Zymbal gland, skin, clitoral gland, small and large intestines, oral cavity, and mammary gland were also induced. Monkeys given IQ developed metastatic hepatocellular carcinomas.