oxyntomodulin and Intestinal-Neoplasms

The effect of daily parenteral administration of a long-acting analogue of somatostatin (SMS 201-995) on the development of intestinal tumours and the rate of crypt cell proliferation in azoxymethane-treated rats has been studied. SMS 201-995 had no significant effect on the number of colonic tumours induced. In the duodenum, SMS 201-995 administration was associated with a change in the number of tumours from 1.4/rat in saline-treated animals to 2.4/rat in animals treated for the last third of the study and 2.8/rat in animals treated with SMS for the entire duration of the study (P less than 0.02). SMS had no significant effect on the rate of cell proliferation in the duodenum, ileum or colon. The inhibition of release of gastrointestinal trophic hormones by this analogue of somatostatin thus does not appear to reduce the number of tumours in the intestine of azoxymethane-treated rats.

Topics: Animals; Antineoplastic Agents; Azoxymethane; Cell Division; Gastrins; Glucagon-Like Peptides; Intestinal Neoplasms; Intestines; Male; Octreotide; Rats; Rats, Inbred Strains; Somatostatin

To assess the association between the putative intestinal trophic hormone enteroglucagon and the development of intestinal tumours, four groups of 20 rats underwent either jejunal transection or 20%, 50%, or 80% proximal small bowel resection. Tumours were induced with azoxymethane 10 mg/kg weekly for 12 weeks. At 26 weeks there was a promotion of colonic neoplasia from a median of 0.5 (range 0-3) per rat in the transection group to 1.0 (0-3) in the 50% resected group (p less than 0.01) but no significant promotion in the 80% resection group. In the small bowel, increasing resection resulted in a progressive promotion of tumours from a median of 1.0 (range 0-3) per rat in the transection group to 2.0 (0-5) in the 50% resection group (p less than 0.001) and 3.0 (0-11) in the 80% group (p less than 0.01). Plasma enteroglucagon was measured at 2, 16, and 26 weeks and was raised seven-fold in the 80% resected group (p less than 0.001). There was a significant correlation between enteroglucagon concentrations and number of duodenal tumours but not colonic tumours. Crypt cell production rate in the duodenum increased from 11.5 +/- 1.9 to 29.2 +/- 1.4 cells/crypt/h in the 80% resected group (p less than 0.001) and showed a close correlation with both enteroglucagon levels and tumour promotion in the small bowel. There were no changes in crypt cell production rate in the colon with resection. This study shows a close association between enteroglucagon concentrations, promotion of tumours and crypt cell production rate in the duodenum but not in the colon.

Topics: Animals; Azoxymethane; Colonic Neoplasms; Duodenal Neoplasms; Gastrointestinal Hormones; Glucagon-Like Peptides; Intestinal Neoplasms; Male; Rats; Rats, Inbred Strains

Gut endocrine cells in a total of 122 intestinal-tract adenocarcinomas induced in inbred Wistar rats by 1,2-dimethylhydrazine dihydrochloride were examined histologically, ultrastructurally, and immunohistochemically for gastrin, somatostatin, vasoactive-intestinal polypeptide (VIP), and glicentin (enteroglucagon). Of the 122 tumors, argyrophil cells were detected in 42 tumors (34.3%) comprising 15 tumors of the well differentiated type and 27 tumors of the poorly differentiated type, including signet-ring-cell carcinomas. Of the 27 tumors of the poorly differentiated type, 12 were regarded as endocrine-cell carcinomas composed of numerous argyrophil or argentaffin cells and mucus-containing cells. Immunohistochemically, 7 of the 12 tumors had glicentin and two of these seven tumors also had gastrin and argentaffin cells synchronously. None of the tumors showed immunoreactivity for somatostatin and VIP. Nine of the 12 tumors metastasized to the lung, pancreas, liver, mesenterium, omentum, and lymph nodes. The metastatic foci of these tumors were also shown to have glicentin and argentaffin cells. Ultrastructurally, four types of endocrine granule were found in the tumor cells and amphicrine cells containing endocrine granules and mucous granules were noted. These endocrine-cell tumors were assumed to develop from totipotent immature cells of endodermal origin.

Topics: 1,2-Dimethylhydrazine; Adenocarcinoma; Animals; Carcinogens; Chromaffin System; Dimethylhydrazines; Enterochromaffin Cells; Female; Gastrins; Glucagon-Like Peptides; Intestinal Neoplasms; Male; Microscopy, Electron; Neoplasm Metastasis; Neoplasms, Experimental; Rats; Rats, Inbred Strains; Somatostatin; Vasoactive Intestinal Peptide

Pancreas and gut hormones are involved in many endocrine and gastrointestinal diseases. Radioimmunoassays for these hormones have proved particularly valuable in diagnosis, localisation and control of treatment of endocrine tumours, of which many are mixed. An estimate based on ten years experience in a homogenous population of 5 million inhabitants (Denmark) suggests, that endocrine gut tumour-syndromes on an average appear with an incidence of 1 patient per year/syndrome/million. At present six different syndromes are known: 1) The insulinoma syndrome, 2) The Zollinger-Ellison syndrome.3) The Verner-Morrison syndrome. 4) The glucagonoma syndrome. 5) The somatostatinoma syndrome, and 6) the carcinoid syndrome. Accordingly diagnostically valuable RIAs for pancreas and gut hormones include those for insulin, gastrin, VIP, HPP, glucagon, somatostatin, and presumably also substance P. It is probably safe to predict that the need for gut and pancreas hormone RIAs within the next decade will increase greatly in order to assure proper management of tumours producing gastroentero-pancreatic hormones.

Topics: Adenoma, Islet Cell; Carcinoid Tumor; Cholecystokinin; Gastric Inhibitory Polypeptide; Gastrins; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptides; Humans; Insulin; Intestinal Neoplasms; Motilin; Pancreatic Hormones; Pancreatic Neoplasms; Pancreatic Polypeptide; Radioimmunoassay; Secretin; Somatostatin; Substance P; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

The presence of serotonin, substance P and enteroglucagon was investigated in 8 argentaffin and argyrophil midgut carcinoid tumours. All tumours were argentaffin and displayed formalin-induced fluorescence indicating a content of serotonin. In addition, all 8 tumours showed substance P immunoreactivity and 7 of them enteroglucagon immunoreactivity. The results indicate that the midgut carcinoid tumours are as a rule multihormonal.

Topics: Aged; Carcinoid Tumor; Female; Fluorescent Antibody Technique; Formaldehyde; Gastrointestinal Hormones; Glucagon-Like Peptides; Humans; Immunoenzyme Techniques; Intestinal Neoplasms; Male; Middle Aged; Serotonin; Substance P

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