oxyntomodulin and Carcinoid-Tumor

Topics: Carcinoid Tumor; Colon; Endocrine Glands; Gastrointestinal Diseases; Gastrointestinal Neoplasms; Glucagon-Like Peptides; Humans; Nervous System; Neuropeptides; Neurosecretory Systems; Peptide PHI; Peptide YY; Peptides; Rectum; Vasoactive Intestinal Peptide

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

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