Studies on the esophagogastric ulcers in swine (6) : effects of dietary factors on the development of gastric lesions and on the acidity and pepsin activity of gastric juice

In order to get a clue to elucidate the incidence of the esophagogastric ulcers in swine and the effects of the diets on it, the two feeding programs were carried out in the form of using several kinds of feeds each of which has a composition and a form different from others. At the next stage, the gastric juice was extracted out of the stomach of the examined swine and analyzed at intervals of a half month. The purpose of this study is to investigate the effects of the diets on the development of the esophagogastric ulcers, and on the pH, the acidity and pepsin activity in the gastric juice. The results obtained are summarized as follows: 1. The percentages of the development of the gastric lesions in the Groups 1, 2, 3, 4, 5, 6 and 7 were 100, 10, 100, 100, 10, 44 and 0 respectively in the first feeding program. The result of our observation shows that the differences in the development of gastric lesions were markedly noteworthy in these experiments, and the Groups 1, 3, and 4 indicated the highest incidence of the disease and the severest ulceration. In the second feeding program, the names of the Groups A and B are used instead of the names Groups 1 and 3 both of which indicated the highest incidence of the ulcers, and the names of the Groups C and D instead of those of the Groups 5 and 2 which indicated the lowest in the first feeding program. On the whole, we obtained the results which reaffirmed the observation in the first feeding program, but only the Group C exceptionally showed a higher incidence of the disease. 2. The digested content in the stomach was more fluid in the Groups 1, 3, 4, A and B than in the other groups, and showed a higher incidence, while contrastively there were more solid and less fluid contents in the other groups which showed a lower one. In the relatively many affected pigs, a backward flow of the bile was observed in the stomach contents. This phenomenon shows that the bile was flowed backward from the endodudenum into the stomach, and will suggest that the peristalses in the affected swine are weaker than the swine without any ulcers. 3. The gastric juice of the affected pigs indicated a lower pH and a higher acidity from the earliest stage of the experiment, while in the case of the pigs without ulcers the gastric juice indicated the lower acidity at the earliest stage but the acidity increased with the lapse of the days. The pH in the gastric juice varied markedly according to the kind of the given feed. 4. During a series of the experiments, the affected gastric juice showed a high acidity from the earliest stage, while the gastric juice in the non-affected stomach showed a low acidity at first, but increased gradually in course of time. And the acidity of the gastric juice which was produced by having a sort of the experimental diet exhibited a similar tendency. According to our present study, the affected pigs showed a lower concentration in free acid (HCl) than known in the previous reports. 5. Our experiments showed that there was little or no pepsin activity in many of the pigs without ulcers, but that the severer the ulcer was, the more pepsin the pig secreted. It was recognized that the pepsin secretion in the pigs with severe ulcers began to increase abruptly 15 to 30 days later. These results may suggest the first stage of the incidence of this disease in swine. 6. The gastric content of the affected swine indicated a high acid (HCl) and full pepsin activity. Both of them played a part in the development of esophagogastric ulcers in swine. It is hypothesized that the hydrochloric acid will give a chemical action to the mucous membrane and denaturalize it, and the ulcer develops and becomes severer by the continuous action both of acid and pepsin.