ABSTRACT
Using a quantitative method, the healing of the experimental gastric ulcer in rats was studied in various states of thyroid function. Rats were made hypothyroid by ingestion of thiouracil (0.1％ solution in drinking water for 10 days). Rats were made slightly hyperthyroid by ingestion of thiouracil and simultaneous administration of T_4 (3?g/100 g/day,ip) for 10 days. Rats were made hyperthyroid by administration of excess T_4 (10?g/100 g/day, ip) for 10 days. The normal rats served as controls. In all of these rats, gastric ulcer was induced by injecting a small quantity of glacial acetic acid into the submucosa of the stomach after laparotomy under aseptic conditions. After operation the rats in four groups were given those drugs as above respectively for 10 days. The volume (7.71?0.52mm~3' 5.5?0.78 mm~3 for control) and area (8.29?0.90mm~2; 4.39?0.73mm~2 for control) of gastric ulcer increased in the rats with hypothyroidism. The healing rate of gastric ulcer retarded (-30?9.4％ for volume healing rate, -50?2.1％ for area healing rate). The volume (4.75?0.88mm~3) and area (4.05?0.93mm~2) of gastric ulcer decreased in the rats with slight hyperthyroidism, and the healing rate of gastric ulcer accelerated (37?3.8％ for volume healing rate, 49?3.2％ for area healing rate). The volume (4.88?0.90mm~3) and area (6.16?0.74mm~2) and the healing rates of gastric ulcer in the rats with hyperthyroidism were similar as those of control. These findings suggested that (1) thyroxine is necessary for healing of the experimental gastric ulcer in rats and (2) thyroxine seem to accelerate healing of the experimental gastric ulcer in rats.