oxyntomodulin and Stomach-Neoplasms

Three separate sets of receptors sensitive to VIP, GIP and pancreatic/entero-glucagons, have been characterized in HGT-1 cells. The order of relative potencies of VIP receptor agonists was VIP greater than rh GRF-43, rh GRF-29 greater than PHI greater than hp GRF-40, secretin. G-37 was about 4 times less potent than G-29 in HGT-1 cells (G-29 greater than G-37), whereas it was about 20 times more potent than G-29 in rat fundic glands (G-37 greater than G-29). Adenylate cyclase in HGT-1 cells was stimulated by VIP, G-29, G-37 and GIP, over a concentration from 3.16 X 10(-9) to 3.16 X 10(-7) M GIP. The experimental data: (1) support the enterogastrone activity of GIP, via adenylate cyclase activation and somatostatin release by gastric D cells; (2) demonstrate that HGT-1 cells originating from a human fundic tumor are sensitive to the glucagon-like peptides G-29 and -37, as rat fundic glands; (3) indicate that the pharmacological properties of the VIP receptor in this human gastric cell line are similar to those characterized in normal human gastric glands.

Topics: Adenylyl Cyclases; Cell Line; Cyclic AMP; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptides; Humans; Receptors, Cell Surface; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Receptors, Vasoactive Intestinal Peptide; Stomach Neoplasms; Vasoactive Intestinal Peptide

Intestinal metaplasia (IM) in the human stomach has previously been classified into a gastric and intestinal mixed (GI-IM) and a solely intestinal phenotype (I-IM). The phenotypes of mucous and endocrine cells were evaluated in 3034 glandular ducts associated with chronic gastritis. In the pyloric region, the relative expression of gastric endocrine cell markers, such as gastrin and somatostatin, decreased gradually from glandular ducts with only gastric mucous cell phenotype (G type) to GI-IM toward I-IM, while that of the intestinal endocrine cell markers, glicentin, gastric inhibitory polypeptide (GIP), and glucagon-like peptide-1 (GLP-1) was inversely correlated. In the fundic region, gastrin-positive cells emerged in the pseudo-pyloric and GI-IM glands, whereas I-IM glands did not possess any gastrin-positive cells, suggesting the presence of a distinct pathway of intestinalization. Double staining revealed coexistence of gastrin- and GLP-1-positive cells in the same gland and occasionally in the same cell in GI-IM glands. These results suggest that the phenotypes of endocrine cells are in line with those for mucous counterparts and support the concept that all of the different types of mucous and endocrine cells in normal and IM glands might be derived from a single progenitor cell in each gland.

Topics: Aged; Chromogranin A; Chromogranins; Endocrine Glands; Female; Gastric Fundus; Gastric Inhibitory Polypeptide; Gastric Mucosa; Gastrins; Glicentin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Immunohistochemistry; Intestines; Male; Metaplasia; Middle Aged; Peptide Fragments; Protein Precursors; Pyloric Antrum; Somatostatin; Stomach Neoplasms

To elucidate the biological and clinicopathological significance of endocrine differentiation in gastric adenocarcinoma, an immunohistochemical study was made of 127 cases with ascertained five-year survivals, and of 45 recent cases of bromodeoxyuridine (BrdU) labeling. Endocrine differentiated cancer cells were demonstrated in 37 out of the 127 cases (29.1%) evaluated by chromogranin A (CGA) immunoreactivity, and all CGA-positive tumors were classified as advanced gastric cancer. Analysis of retrospective five-year survival rates revealed the adenocarcinomas with endocrine differentiation to have had significantly longer survival times than those without endocrine immunoreactivity in stage II, but not in stages III or IV. Double immunolabeling for CGA and BrdU in the other 45 adenocarcinoma cases showed only a single CGA-positive cancer cell with BrdU incorporation among a total of 454 CGA-positive cells examined. There was no significant difference between the labeling indices of the general cancer population and the cancer cells adjacent to CGA-positive cells. In conclusion, endocrine differentiation of gastric cancer is not uncommon, particularly in advancing cancer, and it would be a useful marker for a better prognosis in stage II. Probably, endocrine differentiated cancer cells are almost dormant with virtually no DNA synthesizing activity, and their paracrine effect is most unlikely to work in vivo.

Topics: Adenocarcinoma; Bromodeoxyuridine; Cell Differentiation; Cell Division; Chromogranin A; Chromogranins; Gastrins; Glicentin; Glucagon; Glucagon-Like Peptides; Glycoprotein Hormones, alpha Subunit; Hormones; Humans; Immunohistochemistry; Lymph Nodes; Lymphatic Metastasis; Peptide Fragments; Protein Precursors; Serotonin; Somatostatin; Stomach Neoplasms

We examined 12 depressed tubular adenomas of the stomach pathologically and immunohistochemically in order to clarify the difference between the depressed type and the elevated type. Depressed tubular adenomas showed shallow mucosal depression and, of the 12, nine were endoscopically diagnosed as early gastric cancer. Histologically, the adenoma cells showed dysplasia in varying degree and focal adenocarcinoma occurred in two adenomas measuring over 2 cm. The mean height of the adenoma glands was 0.63 +/- 0.31 mm in the 12 depressed adenomas and 1.32 +/- 0.43 mm in 44 elevated adenomas, while the mean heights of the subjacent mucosa were 0.18 +/- 0.19 mm and 1.07 +/- 0.71 mm, respectively. Thus, depressed adenomas resulted from paucity of the mucosa subjacent to the adenoma glands and the height of the adenomatous glands was half that found in the elevated type. Goblet cells, a variety of endocrine cells and lysozyme-containing cells were found in nine, nine and eight depressed adenomas, respectively, in variable numbers. Hyperplasia of these cells was also detected in depressed adenomas showing mild or moderate dysplasia. Immunohistochemical examination revealed no difference in the phenotypic expression of adenoma cells as between the depressed and the elevated type.

Topics: Adenoma; Antigens, Tumor-Associated, Carbohydrate; Carcinoembryonic Antigen; Glicentin; Glucagon; Glucagon-Like Peptides; Humans; Immunohistochemistry; Muramidase; Peptide Fragments; Protein Precursors; Serotonin; Somatostatin; Stomach Neoplasms

Gastric carcinoid tumor formation has been reported with prolonged achlorhydria in both animals and human beings. The hypothesis in this study was that the ablation of parietal cell function in an animal (mastomys) genetically predisposed to gastric neuroendocrine neoplasia would promote and accelerate tumor formation. Loxtidine, an irreversible H2-receptor blocker, was administered at 1 mg/kg/day in drinking water for 4 months to young mastomys (n = 16). After 4 months of treatment, 14 of 16 animals had gastric carcinoids compared with 0 of 16 young control animals and 4 of 16 older control animals. Ultrastructurally, these tumors were characterized by the presence of neurosecretory granules. Serum gastrin levels were elevated (230 +/- 40 pmol/L) in loxtidine-treated animals compared with control animals (26 +/- 8 pmol/L) (p less than 0.05). In addition, both peptide YY (620 +/- 160 pmol/L) and enteroglucagon (500 +/- 147 pmol/L) were significantly elevated compared with control groups (p less than 0.05). Similarly, in tumor tissue, peptide YY (676 +/- 152 pmol/gm) and enteroglucagon (551 +/- 164 pmol/gm) were found in large quantities, whereas gastrin was undetectable. These observations provide substantial support for the possible pathophysiologic role of gut peptides, particularly gastrin, in the generation of endocrine neoplasia. The advent of endocrine tumors after inhibition of a gut secretory cell (parietal) may be of considerable significance in understanding the genesis of endocrine neoplasia. Whether the drug acts as a neoplastic promoter of enterochromaffin-like cells or the tumor development is related to elevation of peptides such as gastrin cannot be established in this study. Long-term H2-receptor blockade with new potent, irreversible agents as an alternative to surgery may have potential grave implications that require careful consideration.

Topics: Animals; Carcinogens; Carcinoid Tumor; Gastric Mucosa; Gastrointestinal Hormones; Glucagon-Like Peptides; Histamine H1 Antagonists; Hyperplasia; Muridae; Peptide YY; Peptides; Reference Values; Stomach; Stomach Neoplasms; Triazoles

Upper partial gastrectomy for carcinoma of the gastric cardia or fundus is unavoidably accompanied by truncal vagotomy, so it is orthodox practice to carry out pyloroplasty with this procedure. In order to assess the effect of leaving an intact pylorus in this operation, 21 patients were investigated with an oral hypertonic load (200 ml 50 per cent glucose solution), and blood was taken at intervals during the test, for the ileal gut hormones, enteroglucagon and neurotensin, as well as for measurements of haematocrit and blood glucose. Clinical features of dumping during the test were sought. There were 7 patients with upper partial gastrectomy, truncal vagotomy and an intact pylorus, 7 patients without a pylorus (total or near total gastrectomy) and 7 patients not subjected to gastric surgery. No significant difference was found in any of the measurements between gastrectomy patients with an intact pylorus and those draining through an enterostomy. However, both these groups differed significantly from normal controls in having greater rates of rise and higher peak values of enteroglucagon, neurotensin, haematocrit and blood glucose, together with a more frequent occurrence of dumping symptoms during the test. As the above measurements probably reflect transit of glucose into the small intestine, the findings in this study suggest that leaving an intact unstenosed pylorus is unlikely to lead to gastric stasis following upper partial gastrectomy.

Topics: Aged; Gastrectomy; Gastrointestinal Hormones; Glucagon-Like Peptides; Glucose; Hematocrit; Humans; Middle Aged; Neurotensin; Pulse; Pylorus; Stomach Neoplasms

The morphology and histochemistry of gastroduodenal endocrine tumors from 16 patients were studied. All patients underwent operation, in most cases with a preoperative diagnosis of nonendocrine tumor, ulcer, o polyp(s). The argentaffin reaction was positive in three tumors, and the Hellerström--Hellman argyrophil reaction was positive in four tumors. All tumors reacted positively to the Grimelius argyrophil stain, and 13 were positive with the Sevier--Munger argyrophil stain. Gastrin immunoreactivity was found in eight tumors, and substance-P immunoreactivity in seven tumors. No enteroglucagon, adrenal cortex hormone, or pancreatic polypeptide was observed in any of the tumors. Three patients with Sevier--Munger-positive gastric tumors had concurrent pernicious anemia, and 2 patients with gastrin-immunoreactive tumors had acute or chronic gastroduodenal ulceration. The results indicate that the gastroduodenal endocrine tumor as a rule gives no endocrine symptoms and that the tumor type is an unexpected finding at operation. The tumors may contain gastrin, substance P, somatostatin, and serotonin and tend to be multihormonal.

Topics: Adrenocorticotropic Hormone; Adult; Aged; Duodenal Neoplasms; Endocrine System Diseases; Female; Gastrins; Glucagon-Like Peptides; Hormones; Humans; Male; Middle Aged; Pancreatic Polypeptide; Stomach Neoplasms; Substance P

In a consecutive material consisting of 24 stomachs resected due to adenocarcinoma, intestinal metaplasia occurred in 21. Gastrin-producing cells (G-cells) were found to be distributed in a sporadic manner in antra with intestinal metaplasia. Not a single G-cell could be demonstrated in areas with metaplasia, while in the nonmetaplastic areas the distribution of the G-cells corresponded to that of the middle part of the mucosa. This means, that an error can occur when determining the quantity of G-cells, and can explain the previous controversial results regarding the density of G-cells. Enteroglucagon containing cells (GLI-cells) on the contrary were demonstrated in areas with intestinal metaplasia in antra of 19 of the stomachs showing intestinal metaplasia but never in the nonmetaplastic mucosa. This indicated that metaplasia also includes the endocrine cells. The identification of the G-cells and the GLI-cells was carried out by means of indirect immunoperoxidase technique combined with alcian blue pH 2,6-PAS staining.

Topics: Adenocarcinoma; Cell Count; Gastrins; Glucagon-Like Peptides; Humans; Metaplasia; Pyloric Antrum; Stomach Neoplasms

Topics: Animals; Carcinoid Tumor; Cholecystokinin; Dogs; Enterochromaffin Cells; Gastric Inhibitory Polypeptide; Gastric Mucosa; Gastrins; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptides; Humans; Intestinal Mucosa; Intestinal Neoplasms; Pancreatic Polypeptide; Rats; Secretin; Somatostatin; Stomach Neoplasms; Vasoactive Intestinal Peptide