vasoactive-intestinal-peptide and Pancreatic-Diseases

Regulation of pancreatic exocrine secretion is comprised of a complex interplay between hormonal and nervous mechanisms. Stimulatory gut hormones which act via the circulation include secretin, CCK, gastrin and bombesin, while VIP operates through peptidergic nervous release. Pancreatic polypeptide and glucagon are two examples of circulating inhibitory hormones while inhibition by somatostatin is through a paracrine release mechanism. Although the effects of vagal cholinergic nerves have been previously thought to be indirect through hormone release evidence is now accumulating for a direct role. Altered hormone release has been noted in chronic pancreatic insufficiency, cystic fibrosis and coeliac disease and may contribute in an important way to the pathophysiology of these malabsorptive disorders.

Topics: Autonomic Nervous System; Bombesin; Cholecystokinin; Enkephalins; Gastrins; Gastrointestinal Hormones; Humans; Neurotensin; Pancreas; Pancreatic Diseases; Pancreatic Polypeptide; Secretin; Somatostatin; Vagus Nerve; Vasoactive Intestinal Peptide

Topics: Animals; Bombesin; Cholecystokinin; Endorphins; Gastrins; Hormones; Humans; Islets of Langerhans; Nerve Tissue Proteins; Neurons; Neurotensin; Pancreatic Diseases; Reflex; Somatostatin; Vasoactive Intestinal Peptide

Topics: Cholecystokinin; Gastric Inhibitory Polypeptide; Gastrins; Gastrointestinal Diseases; Gastrointestinal Hormones; Humans; Pancreatic Diseases; Secretin; Vasoactive Intestinal Peptide

Topics: Animals; Cholecystokinin; Dogs; Gastric Inhibitory Polypeptide; Gastric Juice; Gastrins; Gastrointestinal Hormones; Humans; Pancreatic Diseases; Radioimmunoassay; Secretin; Syndrome; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

To better understand the relationship between innervation in the sphincter of Oddi and pancreatobiliary diseases, nerve cells which possess nitric oxide synthase (NOS) and/or vasoactive intestinal polypeptide (VIP) were studied immunohistochemically in the sphincter of Oddi and duodenum of humans. Specimens from autopsies included 11 cases with pancreatobiliary diseases and 7 cases without such diseases. An elaborate nerve network was revealed with an anti-S-100 antibody in the sphincter of Oddi and duodenum of all specimens. In the sphincter of Oddi of the control group, approximately 47% of the myenteric nerve cells were NOS positive, whereas 54% were VIP positive. Of the NOS positive nerve cells, 21% were also VIP positive. In contrast, 11% of the nerve cells in the sphincter of Oddi of the disease group were NOS positive while 32% were VIP positive. Within the duodenal myenteric plexus of the control group, 35% of all nerve cells were NOS positive while 40% was VIP positive; among them, 23% of the NOS positive cells were VIP positive. Similar results were observed in the duodenum of the disease group. These data indicate that abundant NOS and VIP positive innervation is present in the sphincter of Oddi and duodenum in humans. The lower proportion of NOS positive or VIP positive nerve cells of the disease group may suggest an inadequacy of the sphincter of Oddi to relax.

Topics: Aged; Aged, 80 and over; Autopsy; Biliary Tract Diseases; Duodenum; Female; Humans; Immunohistochemistry; Male; Middle Aged; Neurons; Nitric Oxide Synthase; Pancreatic Diseases; Sphincter of Oddi; Vasoactive Intestinal Peptide

Studies were conducted to investigate the relationship between development of fibrosis and hemodynamic changes in the pancreas in dogs. The basal blood flow rate in the atrophied, fibrotic pancreas was preserved at almost the same level as in the normal pancreas. Fibrotic pancreas responded to VIP with increased blood flow, but not to administration of secretin. On the other hand, normal pancreas showed a brisk increase of blood flow in response to both of these agents. Our findings suggest that direct arterial acinar blood flow per gram of acini decreases prominently, whereas direct arterial flow to the islets per gram of islet is well maintained after the development of pancreatic fibrosis. It is also suggested that secretin acts indirectly by stimulating metabolic activity of the acinar cells with a secondary increase in blood flow, whereas VIP has a direct effect on the pancreatic vasculature.

Topics: Animals; Blood Pressure; Dogs; Female; Hemodynamics; Male; Pancreas; Pancreatic Diseases; Regional Blood Flow; Secretin; Vasoactive Intestinal Peptide

Topics: Achlorhydria; APUD Cells; Apudoma; Carcinoid Tumor; Carcinoma; Cholecystokinin; Diarrhea; Endocrine System Diseases; Humans; Hypokalemia; Malignant Carcinoid Syndrome; Neoplasms; Pancreatic Diseases; Paraganglioma; Paraneoplastic Endocrine Syndromes; Peptides; Prostaglandins E; Somatostatin; Syndrome; Thyroid Neoplasms; Vasoactive Intestinal Peptide

Relationships between hormonal secretions from the GI tract and gastric functional and/or pathological abnormalities could be studied according to 2 main lines : 1) gastric secretory changes could be the main symptom of hormonal secretory tumors, i.e. acid hypersecretion in the Zollinger Ellison syndrome, acid hyposecretion in pancreatic cholera and in somatostatinoma. In these cases, hormonal hypersecretion is directly responsible for the functional disturbances and the related symptoms; 2) gastric pathological conditions are sometimes accompanied by changes in hormonal secretion, but the level of interdependence is variable : high blood gastrin is directly depending upon the atrophic gastritis in pernicious anemia; this mechanism was also suggested in case of gastric carcinoma. Concerning ulcer disease, numerous problems are unsolved in respect to blood gastrin (basal and stimulated) abnormalities, as well as somatostatin and GIP secretions.

Topics: Aged; Anemia, Pernicious; Cholera; Duodenal Ulcer; Gastric Inhibitory Polypeptide; Gastric Juice; Gastrins; Gastrointestinal Hormones; Gastrointestinal Neoplasms; Humans; Pancreatic Diseases; Pancreatic Neoplasms; Somatostatin; Stomach Diseases; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

In medical practice, diagnostic and therapeutic aspects of gastrointestinal hormones attract interest. Gastrin--in the form of pentagastrin--can be used for gastric secretory analysis and, in the analysis of exocrine pancreatic function, secretin and cholecystokinin-pancreozymin can be employed as stimulants. Diagnosis of hormone-producing tumors is possible by radioimmunological determination of serum levels of the hormone in question: so, dramatically high gastrin levels can be found in the Zollinger-Ellison syndrome while in the Verner-Morrison syndrome, VIP (vasoactive intestinal peptide) values are significantly elevated.--The therapeutic use of gastrointestinal hormones (gastrin, secretin) is waiting in the wings.

Topics: Cholecystokinin; Duodenal Ulcer; Gastrointestinal Diseases; Gastrointestinal Hormones; Humans; Pancreatic Diseases; Pancreatic Neoplasms; Pentagastrin; Secretin; Vasoactive Intestinal Peptide

Small-intestinal perfusion studies with a triple-lumen tube were performed in the jejunum and ileum of 11 patients with a presumptive diagnosis of pancreatic cholera syndrome (PCS). Ultimately PCS was proven to be present in only 3 patients, whereas 6 were discovered to be taking either laxatives or diuretics surreptitiously. In 2 of the 11 patients the cause of the diarrhea could not be determined. In PCS the major abnormality which we observed was that the jejunal mucosa secreted rather than absorbed when perfused with a plasma-like solution. By contrast, the ileum of the PCS patients absorbed a plasma-like solution in a normal fashion; however, one patient failed to absorb sodium and chloride when a solution with low (50 mM) sodium chloride concentration was perfused in the ileum. The volume of endogenous fluid was high in both the jejunum and ileum, presumably because of proximal small-intestinal secretion. Glucose stimulated sodium movement in an absorptive direction in each patient. Studies were repeated in one PCS patient after tumor removal, and his intestinal absorption of water and electrolytes was normal. Patients with diarrhea due to surreptitious ingestion of laxatives and diuretics showed normal absorption in the jejunum and ileum. This study shows that proximal small-bowel secretion was the major cause for diarrhea in our 3 patients with PCS. This cannot be a consequence of diarrhea per se since it was not found in patients with long-standing diarrhea due to surrepitious drug ingestion. Small-intestinal perfusion studies may be helpful in the diagnosis and management of selected cases of severe chronic diarrhea. On the other hand, measurement of plasma VIP concentration, especially by methods currently used in the United States, is of little use and may be misleading.

Topics: Adult; Aged; Cathartics; Diarrhea; Diuretics; Female; Gastrointestinal Hormones; Glucose; Humans; Intestinal Absorption; Intestinal Mucosa; Jejunum; Male; Middle Aged; Pancreatic Diseases; Perfusion; Self Medication; Sodium; Substance-Related Disorders; Syndrome; Vasoactive Intestinal Peptide