Rhythmic oscillating complex (ROC) is a highly organized gastrointestinal motility pattern recently described in fasted avian species. ROCs show several high-speed aborad-propagated contractions that progressively change into others of orad direction. In addition, chickens show migrating motor complexes (MMC) in both fed and fasting states. Recently, motilin was isolated and characterized from chicken small intestine. Accordingly, the aim of this study was to learn whether chicken motilin might be involved in either ROC or MMC induction. Electromyographic recordings were obtained from different areas of the gastrointestinal tract of chickens while motilin was infused. The response to chicken motilin was dose dependent in both fed and fasted animals; a bolus of 4 x 10(-11) mol/kg (n = 5) did not modify the intestinal motor pattern, whereas 4 x 10(-10) and 4 x 10(-9) mol/kg (n = 5 each) induced a complete ROC pattern of 5.2 +/- 0.6 and 10.8 +/- 0.9 min, respectively. ROCs induced by chicken motilin presented exactly the same pattern as that described during a spontaneous ROC. Furthermore, motilin concentration in plasma, measured by radioimmunoassay, increased during a spontaneous ROC. This study suggests that chicken motilin triggers an ROC in chickens. The fact that plasma motilin levels increased during spontaneous ROC strongly suggests that motilin is involved in the induction of the ROC pattern. Motilin seems to play a different role in avian and mammalian species, because a phase III of the MMC was never induced by motilin infusion.
Ghrelin, the endogenous ligand of the growth hormone secretagogue receptor, is released from the stomach. Animal studies suggest that ghrelin stimulates gastrointestinal motor activity.To investigate the influence of ghrelin on gastric emptying rate and meal-related symptoms in idiopathic gastroparesis.In six patients with idiopathic gastroparesis, a breath test was used to measure gastric emptying rates (t(1/2)) for solids and liquids after administration of saline or ghrelin 40 microg/30 min in a double-blind, randomized fashion. At each breath sampling, the patient was asked to grade the intensity of six different symptoms (epigastric pain, bloating, postprandial fullness, nausea, belching and epigastric burning) and these were added to obtain meal-related symptom severity score.Ghrelin significantly enhanced liquid emptying (t(1/2): 86 +/- 7 vs. 53 +/- 6 min, P = 0.02) and tended to enhance solid emptying (144 +/- 45 vs. 98 +/- 15 min, P = 0.06). Ghrelin pre-treatment significantly decreased cumulative meal-related symptom score (196 +/- 30 vs. 136 +/- 23, P = 0.04) and individual scores for fullness (55 +/- 8 vs. 39 +/- 8, P = 0.02), and for pain (40 +/- 8 vs. 16 +/- 5, P < 0.05).In idiopathic gastroparesis, administration of ghrelin enhances gastric emptying and improves meal-related symptoms. These observations suggest a potential for ghrelin receptor agonists in the treatment of gastroparesis.
Erythromycin, a macrolide antibiotic, has recently been shown to have a motilin like effect on gastrointestinal muscle strips. In this study, we have evaluated the effect of erythromycin on patients with delayed gastric emptying and healthy subjects using the dual radionuclide technique. Twelve patients with gastroparesis diabeticorum and ten healthy age- and sex-matched controls were studied. Gastric emptying of solids and liquids was determined using 99mTc-SC scrambled egg and 111In-DTPA in water. Following a baseline study and on a separate day, each patient and control received a 15-min i.v. perfusion of erythromycin starting at meal ingestion. Eleven out of the 12 patients were restudied after a 3-wk oral administration. In patients and controls, i.v. erythromycin dramatically accelerated gastric emptying of both solids and liquids which were emptied at the same rate. After chronic oral administration, solid and liquid emptying remained significantly accelerated. Erythromycin appears to be a very powerful gastrokinetic drug. Derived compounds with the gastrokinetic effect and without the antibiotic activity could be useful in dyspeptic patients with delayed gastric emptying.
The efleot of a. test breakfast, ingested at the refractory period following a duodenal activity front (phase 3 of the migrating motor complex), on plasma motilin levels was studied in eight subjects.A further group of subjects remained fasted and acted as controls.Plasma motilin levels increased significantly following the ingestion of the breakfast, levels also being significantly higher than in the controls.KEY WORDS motilin / postprandial /