cholecystokinin and Gastroparesis

Parkinson's disease (PD) is associated with several non-motor symptoms, such as behavioral changes, urinary dysfunction, sleep disorders, fatigue and, above all, gastrointestinal (GI) dysfunction, including gastric dysmotility, constipation and anorectal dysfunction. Delayed gastric emptying, progressing to gastroparesis, is reported in up to 100% of patients with PD, and it occurs at all stages of the disease with severe consequences to the patient's quality of life. The presence of α-synuclein (α-syn) aggregates in myenteric neurons throughout the digestive tract, as well as morpho-functional alterations of the enteric nervous system (ENS), have been documented in PD. In particular, gastric dysmotility in PD has been associated with an impairment of the brain-gut axis, involving the efferent fibers of the vagal pathway projecting directly to the gastric myenteric plexus. The present review intends to provide an integrated overview of available knowledge on the possible role played by the ENS, considered as a semi-autonomous nervous network, in the pathophysiology of gastric dysmotility in PD. Particular attention has been paid review how translational evidence in humans and studies in pre-clinical models are allowing a better understanding of the functional, neurochemical and molecular alterations likely underlying gastric motor abnormalities occurring in PD.

Topics: alpha-Synuclein; Animals; Cholecystokinin; Efferent Pathways; Enteric Nervous System; Gastric Emptying; Gastrointestinal Motility; Gastroparesis; Humans; Mice; Mice, Transgenic; Models, Neurological; Neuromuscular Junction; Oxidopamine; Parkinson Disease; Parkinsonian Disorders; Protein Aggregates; Rats; Rotenone; Translational Research, Biomedical; Vagus Nerve

Numerous hormones secreted by the gut, during both the fasted state and in response to a meal, influence gastrointestinal motor and/or sensory function, and appear to contribute to the pathogenesis of delayed gastric emptying associated with gastroparesis, functional dyspepsia (FD) and feed intolerance in critical illness. Gut hormones are, accordingly, potential targets for the management of these patients.. This article will discuss the hypersensitivity to enteral fat and endogenous (nutrient-stimulated) and exogenous cholecystokinin (CCK) in patients with FD, and the elevation in both fasting and postprandial CCK levels evident in this group. It will review the use of pharmacological agonists of motilin and ghrelin, which accelerate gastric emptying, in the management of gastroparesis and FD. The frequent finding of markedly delayed gastric emptying in the critically ill will be examined; this is associated with elevated plasma CCK and peptide YY in both the fasted and postprandial states, which may account for the increase in small intestinal nutrient inhibitory feedback on gastric motility in this group. The concepts that the rate of gastric emptying is a major determinant of postprandial glycemic excursions in diabetes, and that modulation of gastric emptying may improve glycemic control, will be addressed; in type 1 and insulin-treated type 2 diabetic patients, co-ordination of insulin administration with nutrient delivery and absorption should be optimized, while type 2 patients who are not on insulin are likely to respond to dietary and/or pharmacological interventions which slow gastric emptying.

Topics: Adipose Tissue; Blood Glucose; Cholecystokinin; Critical Illness; Diabetes Mellitus; Dyspepsia; Gastric Emptying; Gastroparesis; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Peptide YY; Postprandial Period

Anorexia during infection is thought to be mediated by immunoregulatory cytokines such as interleukins 1 and 6 and tumor necrosis factor. This article reviews the potential mechanisms of action by which these cytokines are thought to suppress food intake during infection and examines the proposition that blocking of cytokine activity might be one approach to improving food intake of the infected host.

Topics: Acute-Phase Reaction; Animals; Anorexia; Cholecystokinin; Cytokines; Dinoprostone; Disease Models, Animal; Eating; Fever; Gastroparesis; Humans; Infections; Inflammation Mediators; Leptin; Vagus Nerve

We have shown recently that our model of experimental high-thoracic spinal cord injury (T3-SCI) mirrors the gastrointestinal clinical presentation of neurotrauma patients, whereby T3-SCI animals show diminished gastric emptying and dysmotility. In this study we used cholecystokinin as a model peptide to test the hypothesis that the T3-SCI induced gastroparesis is due, in part, to an impaired vagally-mediated response to gastrointestinal peptides.. We measured the responses to sulfated cholecystokinin (CCK-8s) in control and T3-SCI (3 or 21 days after injury) rats utilizing: (i) c-fos expression in the nucleus tractus solitarius (NTS) following peripherally administered CCK-8s; (ii) in vivo gastric tone and motility following unilateral microinjection of CCK-8s into the dorsal vagal complex (DVC); and (iii) whole cell recordings of glutamatergic synaptic inputs to NTS neurons.. Our results show that: (i) medullary c-fos expression in response to peripheral CCK-8s was significantly lower in T3-SCI rats 3 days after the injury, but recovered to control values at 3 weeks post-SCI, (ii) Unilateral microinjection of CCK-8s in the DVC induced a profound gastric relaxation in control animals, but did not induce any response in T3-SCI rats at both 3 and 21 days after SCI, (iii) Perfusion with CCK-8s increased glutamatergic currents in 55% of NTS neurons from control rats, but failed to induce any response in NTS neurons from T3-SCI rats.. Our data indicate alterations of vagal responses to CCK-8s in T3-SCI rats that may reflect a generalized impairment of gastric vagal neurocircuitry, leading to a reduction of gastric functions after SCI.

Topics: Animals; Cholecystokinin; Excitatory Postsynaptic Potentials; Gastroparesis; Injections, Intraperitoneal; Male; Models, Animal; Patch-Clamp Techniques; Peptide Fragments; Rats; Rats, Wistar; Solitary Nucleus; Spinal Cord Injuries; Stomach; Thoracic Vertebrae; Vagus Nerve

Gastrointestinal (GI) dysmotility and autonomic neuropathy are common problems among diabetics with largely unknown aetiology. Many peptides are involved in the autonomic nervous system regulating the GI tract. The aim of this study was to examine if concentrations of oxytocin, cholecystokinin (CCK), gastrin and vasopressin in plasma differ between diabetics with normal function and dysfunction in GI motility.. Nineteen patients with symptoms from the GI tract who had been examined with gastric emptying scintigraphy, oesophageal manometry, and deep-breathing test were included. They further received a fat-rich meal, after which blood samples were collected and plasma frozen until analysed for hormonal concentrations.. There was an increase in postprandial oxytocin plasma concentration in the group with normal gastric emptying (p = 0.015) whereas subjects with delayed gastric emptying had no increased oxytocin secretion (p = 0.114). Both CCK and gastrin levels increased after the meal, with no differences between subjects with normal respective delayed gastric emptying. The concentration of vasopressin did not increase after the meal. In patients with oesophageal dysmotility the basal level of CCK tended to be higher (p = 0.051) and those with autonomic neuropathy had a higher area under the curve (AUC) of gastrin compared to normal subjects (p = 0.007).. Reduced postprandial secretion of oxytocin was found in patients with delayed gastric emptying, CCK secretion was increased in patients with oesophageal dysmotility, and gastrin secretion was increased in patients with autonomic neuropathy. The findings suggest that disturbed peptide secretion may be part of the pathophysiology of digestive complications in diabetics.

Topics: Autonomic Nervous System Diseases; Case-Control Studies; Cholecystokinin; Diabetic Neuropathies; Esophageal Motility Disorders; Female; Gastric Emptying; Gastrins; Gastroparesis; Humans; Male; Oxytocin; Vasopressins

Chronic pancreatitis should be considered in all patients with unexplained abdominal pain. Management of abdominal pain in these patients continues to pose a formidable challenge. The importance of small duct disease without radiographic abnormalities is now a well-established concept. It is meaningful to determine whether patients with chronic pancreatitis have small duct or large duct disease because this distinction has therapeutic implications. Diagnostic evaluation should begin with simple noninvasive and inexpensive tests like serum trypsinogen and fecal elastase, to be followed where appropriate by more complicated measures such as the secretin hormone stimulation test, especially in patients with suspected small duct disease. No universal causal treatment is available. Non-enteric-coated enzyme preparations are useful for treatment of pain, whereas enteric-coated enzyme preparations are preferred for steatorrhea. Octreotide is used increasingly for abdominal pain that is unresponsive to pancreatic enzyme therapy. When medical therapy for chronic pancreatitis pain has failed, endoscopic therapy, endoscopic ultrasound-guided celiac plexus block, and thoracoscopic splanchnicectomy, performed by experts, may be considered for a highly selected patient population. Surgical ductal decompression is appropriate in patients with considerable pancreatic ductal dilation. The role and efficacy of cholecystokinin-receptor antagonists, antioxidants, and antidepressant drugs remain to be defined.

Topics: Abdominal Pain; Cholecystokinin; Chronic Disease; Devazepide; Endosonography; Gastrointestinal Agents; Gastroparesis; Hormone Antagonists; Humans; Octreotide; Pancreatic Function Tests; Pancreatitis