In order to elucidate pathogenic mechanism of acute gastric mucosal damage, the auther made a new experimental model in which the arterial blood oxygen partial pressure in rats could be reduced to any desired levels and demonstrated that hypoxemia could induce erosions and petechiae in the gastric body with a high incidence. This experiment suggests the possibility that the deficit of oxygen supply to the gastric mucosa may be the chief factor of development of acute gastric mucosal damage. Scanning electron microscopic observation showed swollen cells in areas between gastric pits and, in addition, disruption of apical cell membrane in the same areas. This finding suggests that the initial ultrastructual change of mucosal damage on exposure to hypoxemia may be swelling of cells. Transmission eeltcron microscopic observation also revealed that signs of intracellular disturbance preceded disruption of apical cell membrane.
The present study was undertaken to evaluate the content of immunoreactive somatostatin (IRS) in the gastric specimens obtained by either gastrectomy or biopsy from the patients with gastric ulcer or with duodenal ulcer. The IRS content was measured in acetic extracts of the specimens using the specific radioimmunoassay for somatostatin. It was found that IRS was widely distributed throughout the mucosa of the region of the antrum to the body in resected stomachs with gastric ulcer. In the case of resected stomachs with duodenal ulcer the distribution pattern of mucosal IRS content was not qualitatively different from that of resected stomachs with gastric ulcer. There was no consistent correlation between the content of IRS and immunoreactive gastrin in the neighbouring portion of the antrum in the resected stomachs. In the biopsy specimens, the contents of mucosal IRS with duodenal ulcer were 590±211 pg/mg tissue (mean±S. E. M.) at the acute stage and 599±188pg/mg tissue at the healing stage, whereas those with gastric ulcer were 257±68pg/mg tissue at the acute stage and 321±133 pg/mg tissue at the healing stage. The values of IRS at each stage of duodenal ulcer had a tendency to be highes than those at each corresponding stage of gastric ulcer, but the difference was not significant.
Concentration of carcinoembryonic antigen (CEA) in the gastric juice of patients with various gastric diseases such as carcinoma (18 cases), ulcer (10 cases) and chronic gastritis (50 cases) was measured by radioimmunoassay using the Z-gel method. The CEA levels in the gastric juice were much higher in patients with carcinoma than in those with ulcer. The CEA levels measured by the Z-gel method correlated well with those measured by the Sandwich method. The CEA levels in the gastric juice were mostly much higher in the phase prior to the stimulation with tetragastrin than in the poststimulation phase. The CEA levels in the gastric juice were hardly influenced by both acidity and pepsin activity of the gastric juice but significantly influenced by its volume. The CEA levels in the gastric juice with large volume were mostly lower.
To determine the nature of intracytoplasmic alpha-fetoprotein (AFP) of tumors, especially of digestive organs, the immunohistological method with formalin-fixed paraffin embedded sections following Taylor (PAP technique) was employed. 27 cases with the tumors consisting of 20 cases of hepatocellular carcinoma, 2 cases of gastric carcinoma, 2 cases of duodenal carcinoma and 3 cases of bile duct carcinoma were examined. AFP was apparently localized on the tumor cells of hepatocellular carcinoma, especially in the histological types of Edmondson's type II and III. And the localizations of AFP were recognized in three paterns, that is, AFP was localized only in the tumor cells, both in the tumor cells and liver cells, and sometimes only in the liver cells. In the presented cases of gastric carcinoma and duodenal carcinoma, AFP was mainly localized in the tumor cells, which were histologically medullary carcinoma. On the other hand, in the case of bile duct carcinoma, AFP was not localized in the tumor cells, but in the liver cells around the metastatic lesions of the carcinoma. In our cases, there is a tendency to show that the level of serum AFP was low when cytoplasmic AFP was localized in the liver cells, adversely the serum level of AFP was high when cytoplasmic AFP was localized in the tumor cells. It was presumably considered that the AFP was more remarkably produced by the tumor cells themselves than by the liver cells.
The role of pancreozymin (PZ) and secretin (SC) on synthesis and secretion of the pancreatic enzymes was studied in vivo using 75Selen-laveled methionine as a precursor in normal rat. Pancreatic juice was collected by canulation for determination of amylase activity, protein concentration, protein-bound 75Selen-radioactivity and volume of pancreatic juice before and after PZ or SC stimulation. Following results were obtained. (1) 75Selen-radioactivity in the pancreatic juice corresponds to the pancreatic exocrine function, (2) 75Se-selenomethionine was incorporated into pancreatic enzymes and (3) it was suggested that PZ and SC stimulated enzyme synthesis as well as its release and that SC showed dominant effect in synthesis of enzymes.