[N-nitrosamines in gastric juice of subjects from high incidence area of esophageal cancer].

A total of 353 samples of gastric juice was collected from Lin-xian subjects who were examined by endoscopy. NDMA, NDEA, NMBzA, Npyr, Npip, NSAR and other unknown compounds were detected in the fasting gastric juice. NMBzA, Npyr, Npip and NSAR can induce esophageal cancer in animals. Among the concentrations of N-Nitrosamines in gastric juice, the level of NDMA was the highest, its mean value 17.09 ppb; the level of NDEA stood next with a mean value of 6.95 ppb; the amounts of NMBzA, Npyr and Npip were 4.77, 2.45 and 1.30 ppb, respectively. A positive correlation was found between the amount of N-Nitrosamines in gastric juice and the various lesions in the esophageal epithelium of the subjects, the amount of N-Nitrosamines in gastric juice from subjects with normal esophageal epithelium was lower than that from subjects with marked dysplasia or carcinoma of esophagus. This finding lends further support to their possible involvement in esophageal cancer development.