| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1985: ¥700,000 (Direct Cost: ¥700,000)
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| Research Abstract |
Since 1982, cancer has been the top tanking cause of death among adult diseases in Japn. Although deaths from stomach cancer tend to decline, they still make up about one-fourth the total deaths from cancer in Japna. The carcinogen of stomach cancer has not been identifiled yet but is considered to be closely related to our dietary habit. N-nitroso compounds are carcinogens found in our environment and products of thr reaction between nitrites (NO_2^-) and amines. In animal experiments using over 300 N-nitroso compounds, 80% have proved carcinogenic. Japanese eat more vegetables (NO_2^- and NO_3^-), fish and shellfish (animes) than any other nations. It has not been elucidated yet whether out dietary habit is related to such a high mortality from stomach cancer. This is an important subject to be studied.
In out previous experiments, we quantified N-nitroso compounds and their preqursors in food, conpared the contents of N-nitroso compounds in food before and after cooking, and monitored quantitative changes of salivary nitrited and nitrated after ingestion. This tiem, we lnvestlgated the formation of and the reduction in N-nitroso compounds, especially highly carcinogenic N-nitroso dimethylamine, in a human stomach in in vitro conditions. Unilike experiments using water solutions or artificial gastric juice, the addition of food complicated the assays and made the simple evaluation of these variables impossible. Further investigations should be made on the etiology of stomach cancer in detail in relation to the following factors: problematic dietary habit each individual has meintained for a long time, ever complicated,diversifled diet at present, and environmental factors imposing a stress on individuals.
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