Plasma Levels Of Gastrointestinal Peptides Research Articles

Effect of gastrointestinal function regulatory Kampo medicine, Dai-kenchu-to on human plasma calcitonine gene-related peptide, substance P and somatostatin levels

Background Traditional Chinese herbal (Kampo) medicines, Dai-kenchu-to (DKCT) have been frequently used in the empirical treatment of gastrointestinal obstructions. Although it has been already reported that DKCT increases in the plasma levels of gastrointestinal peptides {vasoactive intestinal polypeptides (VIP) and motilin}, which improves feelings of abdominal coldness and gastrointestinal motility, the mechanism is not yet well understood. In this study, we examined effects of DKCT on the plasma calcitonine gene-related peptide (CGRP), substance P (SP) and somatostatin (SS) levels. Methods DKCT or placebo was orally administered to five healthy male volunteers aged 25–30 years. Venous blood samples were taken before and 20, 40, 60, 90, 120, 180 and 240 min after administration of DKCT. Peptide levels in plasma were measured using a sensitive enzyme immunoassay. Results DKCT (7.5 g) significantly increased in CGRP-like immunoreactive substances (IS) at 40 min, SP-IS at 20–60 min and SS-IS at 180–240 min compared with the each response of placebo. Conclusions In this study, DKCT raised plasma CGRP-, SP- and SS-IS levels. CGRP and SP participate in the control of mucosal blood flow in the gastrointestinal tract. Also, SS participates in the regulation of gastrointestinal motility. DKCT might regulate to the mucosal blood flow by increasing in plasma CGRP- and SP-IS levels. Besides, DKCT might improve the gastrointestinal motility by increasing in plasma SS-IS levels. Clinical Pharmacology & Therapeutics (2005) 77, P13–P13; doi: 10.1016/j.clpt.2004.11.052

Effects of Rabeprazole on Plasma Gastrointestinal Peptides in Healthy Humans

Rabeprazole sodium (rabeprazole), a proton pump inhibitor (PPI), is widely used in the treatment of peptic ulcer and gastroesophageal reflux disease. Recently, some antiulcer medicines have been elucidated pharmacologically from the viewpoint of gut-regulated hormone levels. We examined the effects of rabeprazole on plasma levels of gastrointestinal peptides [gastrin, somatostatin, motilin, substance P, and calcitonin gene-related peptide (CGRP)]. Rabeprazole at a dose of 20 mg or placebo was orally administered to 5 healthy male volunteers aged 25-30 years. Venous blood samples were taken before and 30, 60, 90, 120, 180, 240, and 360 min after administration. Plasma peptide levels were measured using a sensitive enzyme immunoassay. Compared with the response of the placebo group, rabeprazole caused significant (p < 0.05) increases in gastrin-, somatostatin-, and CGRP-like immunoreactive substance (IS) at 360, 180, and 240 min, respectively. Rabeprazole significantly decreased motilin-IS levels at 180 min compared with the placebo group. However, rabeprazole had no effect on plasma substance P-IS levels. Although rabeprazole has potent antisecretry effects, the agent may have little effect on gastrointestinal peptides.

Effects of Erythromycin on Plasma Gastrin, Somatostatin, and Motilin Levels in Healthy Volunteers and Postoperative Cancer Patients

Erythromycin, an antibiotic agent, is known to be a motilin receptor agonist. Motilin is a peptide hormone that regulates gastric motility. One of the gastrointestinal motility regulatory factors has been assumed to be the induction of changes in the levels of peptides (gastrin, somatostatin and motilin) in plasma. We have elucidated the effects of erythromycin by examining changes in the plasma levels of gastroinitestinal peptides. In this study, we investigated the effects of erythromycin on the plasma levels of gastrointestinal peptides (somatostatin, motilin, and gastrin) in healthy volunteers and patients with delayed gastric emptying (DGE). After a single oral administration, erythromycin caused a significant increase in plasma gastrin-like immunoreactive substance (IS) levels at 60 min. But the agent did not alter the levels of somatostatin- and motilin-IS. DGE is the most frequent postoperative complication after pylorus-preserving pancreatoduodenectomy. Molitin is assumed to be one important factor that influences DGE. We also examined the effects of erythromycin on the plasma motilin-IS levels of postoperative patients. The plasma motilin-IS levels were increased after 1 week of oral administration of erythromycin compared with preadministration. These results suggest that the pharmacologic effects of erythromycin in promoting gastric emptying are closely related to changes in plasma motilin-IS levels.

Effect of omeprazole on brain-gut peptides concentrations in human plasma

Purpose Omeprazole, proton pump inhibitor, is widely used in treatment of peptic ulcer, Gastro esophageal reflux disease and eradication of Helicobacter pylori. But the mechanism is not well understood. So we examined the effects of omeprazole on plasma levels of gastrointestinal peptides {somatostatin, gastrin, motilin, vasoactive intestinal peptide (VIP), substance P (SP) and calcitonin gene related peptide (CGRP)}. Methods: Omeprazole or placebo was orally administered in five healthy male volunteers aged 25–30 years. Venous blood samples were taken before and at 30, 60, 90, 120, 180, 240 and 360 min after administration of the drug. Plasma peptide levels were measured using a sensitive enzyme immunoassay. Results: Omeprazole (20mg) causes significant increase in somatostatin-IS at 60-240 min compared with the response of the placebo treated group. Furthermore omeprazole showed 35.1 % (60min) increase of placebo motilin levels and 38.5 % (60min) inhibition of placebo gastrin levels. But omeprazole had no effect on plasma VIP-IS, SP-IS and CGRP-IS levels compared with the placebo treated groups. Conclusions: In this study, omeprazole enhanced somatostatin-IS levels. Somatostatin, a polypeptide, which distributes widely in the gastrointestinal tract, participates in the control of gut motility and hormones secretion. Omeprazole might have pharmacological mechanism not only inhibition of gastric acid secretion but also regulation of gastrointestinal peptide. Clinical Pharmacology & Therapeutics (2004) 75, P11–P11; doi: 10.1016/j.clpt.2003.11.042

An exaggerated sensory component of the gastrocolonic response in patients with irritable bowel syndrome

BACKGROUND/AIMSVisceral 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.SUBJECTSWe...

The role of gastrointestinal peptides on pancreatic secretion in response to different stimulants in conscious rats.

Effects of intragastric food, intraduodenal amino acids, and intravenously administered bombesin and gastrin-releasing peptide (GRP) were examined in conscious rats with pancreatic fistula in terms of responses of exocrine pancreatic secretion, plasma levels gastrin, and cholecystokinin (CCK). Pancreatic juice and blood samples were collected at regular intervals before and after the stimuli. Intragastric food increased pancreatic secretion and plasma levels of gastrin and CCK. Intraduodenal infusion of amino acids had no effect on pancreatic secretion and plasma levels of gastrin and CCK. Intravenous infusion of bombesin at 1 microgram/kg/h induced significant increases in pancreatic volume and protein outputs, but had no effect on plasma levels of gastrin and CCK. Bombesin infusion at 10 micrograms/kg/h resulted in significant increases in pancreatic volume and protein outputs as well as plasma gastrin levels, but had no effect on plasma CCK levels. Intravenous infusion of GRP induced increases in pancreatic volume and protein outputs and plasma gastrin levels, but had no effect on CCK levels. Antrectomy resulted in significant decreases in basal levels of plasma gastrin. GRP-stimulated pancreatic volume and protein outputs were not significantly changed by antrectomy. In rats that underwent antrectomy, GRP infusion significantly increased pancreatic volume and protein outputs, but had no effect on plasma levels of gastrin and CCK. Food-stimulated pancreatic secretion and plasma levels of gastrointestinal peptides of rats were similar to other species, but amino acids, bombesin, or GRP may not be the stimulants for CCK release in rats. The stimuli that release CCK from duodenal mucosa probably varies among species.