EFFECTS OF SODIUM-CHLORIDE, SACCHARIN, PHENOBARBITAL AND ASPIRIN ON GASTRIC CARCINOGENESIS IN RATS AFTER INITIATION WITH N-METHYL-N'-NITRO-N-NITROSOGUANIDINE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 75  (6) , 494-501
Abstract
NaCl, saccharin sodium, phenobarbital sodium and aspirin were tested for tumor-promoting activity in the glandular stomach of rats after initiation with N-methyl-N''-nitro-N-nitrosoguanidine (MNNG) coupled with administration of a high salt diet. Male outbred Wistar rats were given MNNG in the drinking water (100 mg/l) for 8 wk, and during this period they were fed on diet supplemented with 10% NaCl. They were divided into 5 groups and fed on the basal diet or one of various diets supplemented with 10% NaCl 5% saccharin, 0.05% phenobarbital or 1% aspirin until the end of the experiment. All animals were killed at the 40th experimental wk for necropsy and histological examination. The incidence of adenocarcinoma was increased in the group given NaCl following initiation by MNNG and NaCl as compared with the group given MNNG and NaCl initiation only, but not significantly. The incidence of preneoplastic hyperplasia was significantly increased in this group. Saccharin also enhanced the development of adenocarcinomas of the glandular stomach. Dietary administration of NaCl or saccharin after MNNG tends to promote tumor development. Phenobarbital or aspirin did not enhance tumor development, aspirin in fact rather showing a tendency to decrease the tumor incidence.