Inhibitory effect of prolonged administration of cysteamine on experimental carcinogenesis in rat stomach induced by N‐methyl‐N′‐nitro‐N‐nitrosoguanidine

Tatsuta, Masaharu; Iishi, Hiroyasu; Yamamura, Hisako; Baba, Miyako; Mikuni, Tomiko; Taniguchi, Haruo

doi:10.1002/ijc.2910410318

Cited by 43 publications

(34 citation statements)

References 20 publications

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“…Watanabe et al (1992) found that oral administration of NaCl after MNNG pretreatment significantly increased the incidence of gastric cancers and that it also significantly increased the height of the pyloric mucosa. Many investigators (Takahashi et al, 1986;Tatsuta et al, 1988a;Kobori et al, 1984) have indicated that enhancing effects on gastric carcinogenesis may be related to stimulation of cell proliferation and elongation of the mucosa. These findings suggest that a non-genotoxic component increases tumour yield when administered subsequent to a genotoxic agent.…”

Section: Discussionmentioning

confidence: 99%

Enhancement by thyroxine of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

Tatsuta¹,

Baba²,

Yamamoto³

et al. 1993

Br J Cancer

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25 weeks, the rats received s.c. injections of T4 (0.2 jug kg-') in depot form every other day until the end of the experiment in Week 52. This long-term treatment with T4 significantly increased the incidence of gastric cancers in Week 52. However, it did not influence the histological type of the gastric cancers. It also caused significant increases in the labelling indices of the fundic and antral epithelial cells. These findings indicate that T4 enhances the development of gastric cancers, and that its effect may be related to its effect in increasing proliferation of gastric epithelial cells.Thyroid hormones have important regulatory roles in the morphology and biochemistry of gastrointestinal mucosal cells (Hernandez et al., 1988). Long-term T4 administration increased the mitotic activity of the fundic 'stem' cells of the stomach and basal and secretagogue-stimulated acid secretion via its effect on parietal cell mass (Adeniyi & Olowookorun, 1989). We recently found that prolonged administration of T4 significantly increased the incidence of rat colon tumours induced by azoxymethane (Iishi et al., 1992). These findings suggest that T4 might influence gastric carcinogenesis. Therefore, in the present work, we examined the effect of treatment of rats with T4 on the development of gastric cancers in rats. Materials and methods AnimalsSixty 6-week-old male Wistar rats (SLC, Shizuoka, Japan) were used in this study. (Siegel, 1956). Other results were all analysed by one-way analysis of variance with Dunn's multiple comparison (Snedecor & Cochran, 1967;Miller, 1966

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Section: Discussionmentioning

confidence: 99%

Enhancement by thyroxine of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

Tatsuta¹,

Baba²,

Yamamoto³

et al. 1993

Br J Cancer

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“…Starting at 3 weeks of age, rats were given drinking water containing MNNG at a concentration of 50 g/mL for 25 weeks. The MNNG solution was supplied from bottles covered with aluminum foil to prevent photolysis and refilled every other day as reported previously (30). After 25 weeks, MNNG administration was stopped, and normal tap water was supplied.…”

Section: Methodsmentioning

confidence: 99%

In vivo Detection of Gastric Cancer in Rats by Electron Paramagnetic Resonance Imaging

Mikuni

Petryakov

et al. 2004

Cancer Research

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Electron paramagnetic resonance imaging (EPRI) enables noninvasive spatial mapping of free radical metabolism and has recently been shown to provide in vivo physiologic information regarding alterations in the redox state of tumors and neoplastic tissues. With the use of nitroxide spin probes, it has been shown that certain tumors possess a highly reduced state. To determine whether EPRI can be used for early detection and visualization of gastric carcinoma based on its altered redox metabolism, studies were performed in a rat gastric cancer model induced by 1-methyl-3-nitro-1-nitrosoguanidine. Using a specialized 750 MHz resonator and EPRI instrument, a technique was developed for imaging nitroxide radicals in the whole stomach. In vivo three-dimensional EPRI of the stomach of rats with continuous intravenous administration of nitroxide 3-carboxamido-2,2,5,5-tetramethylpyrrolidine-N-oxyl (3-carbamoyl-proxyl) [3-CP] was performed. Whereas electron paramagnetic resonance images from untreated controls provide a uniform visualization of the stomach mucosa and wall, in the treated rats with gastric cancer, holes were present in the image at the locations of tumors. With localized spectroscopy, it was confirmed that the tumor regions were devoid of signal, and this was largely due to the presence of a more reduced state with rapid reduction of nitroxide. Pharmacokinetic studies indicated that 3-CP in tumors was rapidly reduced to an undetectable level, whereas the 3-CP levels in normal stomach tissue persisted. Near-infrared reflectance measurements of indocyanine green dye uptake indicated that there were no significant differences in tumor versus normal mucosal perfusion. From these results, we concluded that gastric cancer tumors could be distinguished from normal tissue based primarily on the marked difference in their rate of radical metabolism. Because alterations in cellular redox state and radical metabolism are of critical importance in tumor biology and treatment, this methodology should provide an important new tool for the study and visualization of gastric carcinoma and may also be of use in other cancer models.

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“…Oral administration of high dose phenylalanine significantly increased the basal serum gastrin level and significantly decreased the norepinephrine concentration in the antral portion of the gastric wall, as well as the labelling indices of antral mucosa. These findings indicate that orally administered phenylalanine inhibits the development of gastric cancers.Gastrointestinal regulatory peptides, such as vasoactive intestinal peptide (lishi et al, 1987), secretin (Howatson & Carter, 1987), cholecystokinin and its analogue (Satake et al, 1986), and gastrin (Tatsuta et al, 1977b), have been found to regulate development of cancers of the gastrointestinal tract and the pancreas. We recently found that prolonged alternate-day administration of the potent duodenal ulcerogen cysteamine after 25 weeks of N-methyl-N'-nitro-Nnitrosoguanidine (MNNG) treatment led to marked hypergastrinaemia and also to significant protection against the development of gastric cancers (Tatsuta et al, 1988a).…”

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confidence: 99%

Protection by oral phenylalanine against gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

Tatsuta¹,

Baba²,

Okuda³

et al. 1990

Br J Cancer

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Summary The effect of oral administration of L-phenylalanine on the incidence and histology of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine was investigated in inbred Wistar rats. Oral administration of 6% phenylalanine after 25 weeks of treatment with the carcinogen significantly reduced the incidence and number of adenocarcinomas of the glandular stomach at experimental week 52. Oral administration of high dose phenylalanine significantly increased the basal serum gastrin level and significantly decreased the norepinephrine concentration in the antral portion of the gastric wall, as well as the labelling indices of antral mucosa. These findings indicate that orally administered phenylalanine inhibits the development of gastric cancers.Gastrointestinal regulatory peptides, such as vasoactive intestinal peptide (lishi et al., 1987), secretin (Howatson & Carter, 1987), cholecystokinin and its analogue (Satake et al., 1986), and gastrin (Tatsuta et al., 1977b), have been found to regulate development of cancers of the gastrointestinal tract and the pancreas. We recently found that prolonged alternate-day administration of the potent duodenal ulcerogen cysteamine after 25 weeks of N-methyl-N'-nitro-Nnitrosoguanidine (MNNG) treatment led to marked hypergastrinaemia and also to significant protection against the development of gastric cancers (Tatsuta et al., 1988a). These findings indicate that exogenous and endogenous gastrin may be closely associated with gastric carcinogenesis.Of all the gastrointestinal regulatory peptides, the antral hormone gastrin has been most extensively studied. Food plays an important role in the regulation of serum and tissue gastrin levels. Lichtenberger et al. (1982) reported that of the amino acids, L-phenylalanine (phenylalanine) has a strong stimulatory action on gastrin release. These findings suggest that phenylalanine should inhibit gastric carcinogenesis. Therefore, to test this possibility in the present work we examined the effect of oral administration of phenylalanine on the incidence, number, and histological appearance of adenocarcinomas in rats induced by MNNG. Materials and methods AnimalsYoung male Wistar rats (n = 60), aged about 6 weeks, were purchased from SLC, Japan (Shizuoka, Japan). The rats were housed in suspended wire-bottomed metal cages in animal quarters with controlled temperature (21-22°C), humidity (30-50%), and light (12-h cycle), and had free access to chow pellets (Oriental Yeast, Tokyo, Japan). Beginning with experimental week 26, the MNNG-treated rats were given normal tap water. They were divided into two groups, which were treated until the end of the experiment at week 52 as follows: group 1 (30 rats) were given regular laboratory chow pellets containing 1% phenylalanine ad libitum; group 2 (30 rats) received 6% phenylalanine orally. Phenylalanine (Sigma Chemical, St Louis, MO) was added to regular chow pellets and given ad libitum until the end of the experiment. The chow pellets, with or without added phenylalanine, w...

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Inhibitory effect of prolonged administration of cysteamine on experimental carcinogenesis in rat stomach induced by N‐methyl‐N′‐nitro‐N‐nitrosoguanidine

Cited by 43 publications

References 20 publications

Enhancement by thyroxine of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

Enhancement by thyroxine of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

In vivo Detection of Gastric Cancer in Rats by Electron Paramagnetic Resonance Imaging

Protection by oral phenylalanine against gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

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