neuropeptide-y and Colonic-Diseases--Functional

In irritable bowel syndrome (IBS), motility disturbances occur from the upper gastrointestinal tract to the distal colon, where regulatory peptides have a wide-spread distribution. Studies on basal and postprandial plasma levels of different gut hormones show that VIP, CCK, and motilin may be closely related to the symptoms including abdominal pain, diarrhea and constipation. In addition, peptide YY and NPY have effects on absorption in the intestine, and some opioid peptides exert actions on colonic motility in IBS patients. Recent studies revealed that gall bladder in IBS has an abnormal sensitivity to CCK-8, indicating that IBS patients has an generalized abnormality of the smooth muscle of the digestive tract. Gut hormones, which act as hormones, neurotransmitters and neuromodulators depending on their releasing site, may therefore play an important role in IBS patients.

Topics: Animals; Cholecystokinin; Colonic Diseases, Functional; Gastrointestinal Motility; Humans; Motilin; Neuropeptide Y; Peptide YY; Peptides; Rats; Rats, Sprague-Dawley; Vasoactive Intestinal Peptide

Visceral hypersensitivity is a feature of the irritable bowel syndrome (IBS). Postprandial symptoms are common in these patients. The effects of nutrients on colonic perception in IBS are incompletely understood.. We studied 13 healthy subjects and 16 patients with IBS-eight had diarrhoea predominant (IBS-D) and eight constipation predominant (IBS-C) IBS.. Colonic perception thresholds to balloon distension and viscerosomatic referral pattern were assessed before and after duodenal infusion of lipid or saline, respectively. At the end of the infusions, plasma levels of gastrointestinal peptides were determined.. Lipids lowered the thresholds for first sensation, gas, discomfort, and pain in the IBS group but only for gas in the control group. The percent reduction in thresholds for gas and pain after lipids was greater in the IBS and IBS-D groups but not in the IBS-C group compared with controls. IBS patients had an increased area of referred discomfort and pain after lipids compared with before infusion whereas the referral area remained unchanged in controls. No group differences in colonic tone or compliance were observed. In both groups higher levels of cholecystokinin, pancreatic polypeptide, peptide YY, vasoactive intestinal polypeptide, and neuropeptide Y were seen after lipids. Motilin levels were higher in patients and differences in the subgroups were observed. Levels of corticotrophin releasing factor were lower in the constipated group than in the diarrhoea group.. Postprandial symptoms in IBS patients may be explained in part by a nutrient dependent exaggerated sensory component of the gastrocolonic response.

Topics: Adult; Analysis of Variance; Case-Control Studies; Catheterization; Cholecystokinin; Colon; Colonic Diseases, Functional; Constipation; Diarrhea; Dietary Fats; Female; Humans; Male; Middle Aged; Motilin; Neuropeptide Y; Pain Threshold; Pancreatic Polypeptide; Peptide YY; Postprandial Period; Pressure; Statistics, Nonparametric; Stomach; Vasoactive Intestinal Peptide

Irritable bowel syndrome (IBS) is a colonic function disorder. Both pinaverlum bromide (a selective calcium channel blocker) and mebeverine (an antispasmodic) are reported to be effective in the long-term (12-16 weeks) treatment of IBS patients. Their efficacy in the short-term treatment of IBS patients and colonic transit time is unclear. Furthermore, substance P and neuropeptide Y have either excitatory or inhibitory effects on colonic motility. Whether the efficacy of both drugs is mediated through these neuropeptides remains unknown.. A clinical trial was conducted with 91 patients with diarrhoea-predominant IBS. After basal measurement of the total colonic transit time, IBS patients were randomized to receive either pinaverlum bromide (50 mg, t.i.d.) or mebeverine (100 mg, t.i.d.) for 2 weeks. The symptomatic scores regarding defaecation, total colonic transit time and serum levels of substance P and neuropeptide Y were measured before and after treatments. The daily defaecation frequency was markedly decreased after treatment (pinaverlum bromide, 2.9+/-1.2 vs 2.0+/-1.0, P< 0.05; mebeverine, 2.7+/-1.1 vs 2.1+/-1.0, P< 0.05). The stool consistency became well formed after both treatments (P< 0.05). Both drugs similarly improved the global well-being in these IBS patients (pinaverlum bromide vs mebeverine 73.4 vs 71.8%, P> 0.05). The total colonic transit time was significantly prolonged only after pinaverlum bromide treatment (21.4+/-15.5 vs 30.8+/-14.8 h, P< 0.01). Neither substance P nor neuropeptide Y serum level was significantly changed after either treatments.. Pinaverlum bromide and mebeverine have similar therapeutic efficacies on diarrhoea-predominant IBS patients. Prolonged colonic transit time may be one of the factors responsible for the efficacy of pinaverlum bromide on the IBS patients. Substance P and neuropeptideY appear less important in the pathogenesis of diarrhoea-predominant IBS.

Topics: Calcium Channel Blockers; Colonic Diseases, Functional; Diarrhea; Female; Gastrointestinal Motility; Humans; Immunoenzyme Techniques; Male; Middle Aged; Morpholines; Neuropeptide Y; Parasympatholytics; Phenethylamines; Statistics, Nonparametric; Substance P; Surveys and Questionnaires; Treatment Outcome

To assess the levels of gut peptides involved in gastrointestinal motor, secretory and sensory function in colonic biopsies in irritable bowel syndrome (IBS) patients and healthy controls.. We studied 34 patients with IBS and 15 subjects without gastrointestinal symptoms. The predominant bowel pattern in the IBS patients was constipation in 17 patients (IBS-C) and diarrhoea in 17 patients (IBS-D). With radioimmunoassay, the levels of vasoactive intestinal peptide (VIP), substance P, neuropeptide Y (NPY) and peptide YY (PYY) were analysed in biopsies from the descending colon and ascending colon obtained during colonoscopy.. The IBS patients had lower levels of PYY in the descending colon than the controls, but the levels in the ascending colon did not differ. The NPY levels were lower in IBS-D than in IBS-C, both in the ascending colon and in the descending colon. Low levels of VIP were more common in IBS patients, but mean levels did not differ between groups. No group differences were observed for substance P. The levels of VIP, substance P and NPY were higher in the ascending colon than in the descending colon, whereas the opposite pattern was seen for PYY.. IBS patients demonstrate lower levels of PYY in the descending colon than controls. Colonic NPY levels differ between IBS subgroups based on the predominant bowel pattern. These findings may reflect the pathophysiology of IBS and the symptom variation within the IBS population.

Topics: Adult; Aged; Biopsy; Case-Control Studies; Colon; Colonic Diseases, Functional; Constipation; Diarrhea; Female; Humans; Male; Middle Aged; Neuropeptide Y; Peptide YY; Substance P; Vasoactive Intestinal Peptide