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Motilin Receptor Agonist (motilin + receptor_agonist)

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Medical Sciences100%

Selected Abstracts

MITEMCINAL (GM-611), AN ORALLY ACTIVE MOTILIN RECEPTOR AGONIST, IMPROVES DELAYED GASTRIC EMPTYING IN A CANINE MODEL OF DIABETIC GASTROPARESIS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2008
Mitsu Onoma
SUMMARY 1The aim of the present study was to evaluate the effects of mitemcinal (GM-611), an orally active motilin receptor agonist, on delayed gastric emptying in a canine model of diabetic gastroparesis and to compare these effects with those of cisapride. 2Moderate hyperglycaemia was induced by a single intravenous injection of a mixture of streptozotocin (30 mg/kg) and alloxan (50 mg/kg). Dogs that maintained moderate hyperglycaemia (fasting plasma glucose 200,300 mg/dL) without insulin treatment were selected and gastric emptying in these dogs was determined by the paracetamol method. 3One year after the onset of diabetes, there was no difference in the gastric emptying of normal and diabetic dogs. However, after 5 years, the diabetic dogs showed delayed gastric emptying. The motor nerve conduction velocity of the tibial nerve was significantly lower in diabetic dogs comapred with normal dogs at both time points. 4Histopathological examination at the end of the study showed that there were fewer nerve fibres in both dorsal vagal and tibial nerves of diabetic dogs comapred with normal dogs. The onset of delayed gastric emptying is thought to have occurred gradually, in parallel with abnormal autonomic nerve function induced by the long period of moderate hyperglycaemia. 5Oral administration of mitemcinal (0.125, 0.25 or 0.5 mg/kg) dose-dependently accelerated delayed gastric emptying, significant at 0.5 mg/kg, in diabetic dogs, whereas cisapride (1, 3 or 10 mg/kg) had no significant effect. These results add to the existing evidence that mitemcinal is likely to be useful for treating diabetic gastroparesis. [source]

Stimulatory action of mitemcinal (GM-611), an acid-resistant non-peptide motilin receptor agonist, on colonic motor activity and defecation: spontaneous and mitemcinal-induced giant migrating contractions during defecation in dogs

NEUROGASTROENTEROLOGY & MOTILITY, Issue 10 2009
T. Hirabayashi
Abstract, The aim of this study was to characterize giant migrating contractions (GMCs) during spontaneous defecation in dogs and to investigate the effect of mitemcinal (an orally active and highly acid-resistant motilin receptor agonist) on colonic motility to assess the possibility of using it for the treatment of colonic motility disorders. To assess colonic motility, strain-gauge force transducers were implanted on the gastrointestinal tract of five dogs, and the behaviour of the dogs was monitored with a noctovision-video camera system. The effect of mitemcinal (0, 3, 10 or 30 mg per dog) and sennoside (300 mg per dog) on colonic motility was assessed 24 h after oral administration. During a 39-day period, the starting point of most of the 140 GMCs was between the transverse colon and the descending colon, but some variation was observed. In the daytime, the GMCs originated from somewhat more proximal positions than at night. Mitemcinal caused an increase in the GMC-index (integration of contractile amplitude and duration) and proximal translocation of the GMC starting point, but did not cause an increase in the number of defecations 12 h after administration. Sennoside, however, caused a significant increase in the number of defecations, an increase in the GMC-index, and prolongation of the duration of GMCs. The GMC starting point in the canine colon varied during spontaneous defecation. Mitemcinal was a potent prokinetic drug to mimic a spontaneous defecation compared with sennoside. Mitemcinal evacuates more intestinal luminal contents during the defecation than does sennoside. [source]

Differences between the abilities of tegaserod and motilin receptor agonists to stimulate gastric motility in vitro

BRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2007
E M Jarvie
Background and purpose: Motilin or 5-HT4 receptor agonists stimulate gastrointestinal motility. Differences in activity are suggested but direct comparisons are few. A method was devised to directly compare the gastric prokinetic activities of motilin, the motilin receptor agonist, erythromycin, and the 5-HT4 receptor agonist, tegaserod. Experimental approach: Gastric prokinetic-like activity was assessed by measuring the ability to facilitate cholinergically-mediated contractions evoked by electrical field stimulation (EFS) in rabbit isolated stomach. Comparisons were made between potency, maximal activity and duration of responses. Key results: Rabbit motilin (r.motilin) 0.003,0.3,M, [Nle13]motilin 0.003,0.3,M, erythromycin 0.3,10,M and tegaserod 0.1,10,M caused concentration , dependent potentiation of EFS-evoked contractions. The potency ranking was r.motilin = [Nle13]motilin > tegaserod > erythromycin. The Emax ranking was r.motilin = [Nle13]motilin = erythromycin > tegaserod. Responses to r.motilin and [Nle13]motilin faded rapidly (t1/2 9 and 11 min, respectively) whereas those to erythromycin and tegaserod were maintained longer (t1/2 24 and 28 min). The difference did not appear to be due to peptide degradation. A second application of [Nle13]motilin was excitatory after 60 min contact and fade of the initial response (responses to 0.03 and 0.1,M [Nle13]motilin were not different from those caused by the first application). Conclusions and implications: Prokinetic-like activities of the 5-HT4 agonist tegaserod and the motilin receptor agonists were compared by measuring changes in cholinergically-mediated contractions. This novel approach highlighted important differences between classes (greater Emax of motilin, compared with tegaserod) and for the first time, within each class (short t1/2 for motilin, compared with erythromycin). British Journal of Pharmacology (2007) 150, 455,462. doi:10.1038/sj.bjp.0707118 [source]

MITEMCINAL (GM-611), AN ORALLY ACTIVE MOTILIN RECEPTOR AGONIST, IMPROVES DELAYED GASTRIC EMPTYING IN A CANINE MODEL OF DIABETIC GASTROPARESIS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2008
Mitsu Onoma
SUMMARY 1The aim of the present study was to evaluate the effects of mitemcinal (GM-611), an orally active motilin receptor agonist, on delayed gastric emptying in a canine model of diabetic gastroparesis and to compare these effects with those of cisapride. 2Moderate hyperglycaemia was induced by a single intravenous injection of a mixture of streptozotocin (30 mg/kg) and alloxan (50 mg/kg). Dogs that maintained moderate hyperglycaemia (fasting plasma glucose 200,300 mg/dL) without insulin treatment were selected and gastric emptying in these dogs was determined by the paracetamol method. 3One year after the onset of diabetes, there was no difference in the gastric emptying of normal and diabetic dogs. However, after 5 years, the diabetic dogs showed delayed gastric emptying. The motor nerve conduction velocity of the tibial nerve was significantly lower in diabetic dogs comapred with normal dogs at both time points. 4Histopathological examination at the end of the study showed that there were fewer nerve fibres in both dorsal vagal and tibial nerves of diabetic dogs comapred with normal dogs. The onset of delayed gastric emptying is thought to have occurred gradually, in parallel with abnormal autonomic nerve function induced by the long period of moderate hyperglycaemia. 5Oral administration of mitemcinal (0.125, 0.25 or 0.5 mg/kg) dose-dependently accelerated delayed gastric emptying, significant at 0.5 mg/kg, in diabetic dogs, whereas cisapride (1, 3 or 10 mg/kg) had no significant effect. These results add to the existing evidence that mitemcinal is likely to be useful for treating diabetic gastroparesis. [source]

Differences between the abilities of tegaserod and motilin receptor agonists to stimulate gastric motility in vitro

BRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2007
E M Jarvie
Background and purpose: Motilin or 5-HT4 receptor agonists stimulate gastrointestinal motility. Differences in activity are suggested but direct comparisons are few. A method was devised to directly compare the gastric prokinetic activities of motilin, the motilin receptor agonist, erythromycin, and the 5-HT4 receptor agonist, tegaserod. Experimental approach: Gastric prokinetic-like activity was assessed by measuring the ability to facilitate cholinergically-mediated contractions evoked by electrical field stimulation (EFS) in rabbit isolated stomach. Comparisons were made between potency, maximal activity and duration of responses. Key results: Rabbit motilin (r.motilin) 0.003,0.3,M, [Nle13]motilin 0.003,0.3,M, erythromycin 0.3,10,M and tegaserod 0.1,10,M caused concentration , dependent potentiation of EFS-evoked contractions. The potency ranking was r.motilin = [Nle13]motilin > tegaserod > erythromycin. The Emax ranking was r.motilin = [Nle13]motilin = erythromycin > tegaserod. Responses to r.motilin and [Nle13]motilin faded rapidly (t1/2 9 and 11 min, respectively) whereas those to erythromycin and tegaserod were maintained longer (t1/2 24 and 28 min). The difference did not appear to be due to peptide degradation. A second application of [Nle13]motilin was excitatory after 60 min contact and fade of the initial response (responses to 0.03 and 0.1,M [Nle13]motilin were not different from those caused by the first application). Conclusions and implications: Prokinetic-like activities of the 5-HT4 agonist tegaserod and the motilin receptor agonists were compared by measuring changes in cholinergically-mediated contractions. This novel approach highlighted important differences between classes (greater Emax of motilin, compared with tegaserod) and for the first time, within each class (short t1/2 for motilin, compared with erythromycin). British Journal of Pharmacology (2007) 150, 455,462. doi:10.1038/sj.bjp.0707118 [source]