摘要:

AbstractThe role of cholecystokinin in mediating the effects of intraduodenal fat infusion on gastric motility and gastric emptying and the pattern of transpyloric flow was evaluated in conscious pigs. Concurrent measurements of antropyloroduodenal motility with an eight‐channel sleeve/sidehole catheter, transpyloric flow and gastric emptying after instillation of 1000 ml of saline into the stomach, were made during intraduodenal infusion of either normal saline or oleic acid at 5 ml min−1. Studies with intraduodenal oleic acid were performed with and without intravenous infusion of loxiglumide (30 mg kg−1intravenous bolus 15 min before intraduodenal oleic acid, followed by intravenous infusion of 10 mg kg−1h−1), Intraduodenal oleic acid was associated with stimulation of isolated pyloric pressure waves (P<0.05), inhibition of antral pressure waves (P<0.05), reduced pulsatile transpyloric flow (P<0.05) and retardation of gastric emptying (P<0.05). when compared to intraduodenal saline. Loxiglumide prevented retardation of gastric emptying by intraduodenal oleic acid (P<0.05), and maintained it at values that were not significantly different from saline. After loxiglumide there were more antral pressure waves (P<0.05) and less isolated pyloric pressure waves (P<0.05) when compared to oleic acid.These results indicate that the effects of intraduodenal oleic acid on gastric and pyloric motility, and gastric emptying are largely mediated by CCK‐dependent

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00182.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractIntracerebroventricular (i.c.v.) injection of interleukin‐1β (IL‐1β) in fed rats induces stimulation of caecocolonic contractions, involving corticotropin‐releasing factor (CRF) and the reappearance of the fasted motor pattern (presence of migrating myoelectric complexes, MMCs) at the small intestinal level, which is mediated by prostaglandins (PGs). The mechanisms of these effects were further investigated by focusing on the possible involvement of central monoaminergic systems. Motility was appraised in conscious rats chronically implanted with electrodes in the jejunum and caecum, and a catheter in a lateral ventricle of the brain. IL‐1β (15 ng, i.c.v.) was administered in fed rats that were untreated, or after previous administration of either antagonists of α1and α2adrenergic (prazocin and yohimbine), D1and D2dopaminergic (SCH 23390 and sulpiride) and 5HT3serotonergic (granisetron) receptors. Only prazocin and yohimbine (1 mg kg−1i.p.) significantly reduced the duration of the MMC pattern induced by IL‐1β at the jejunal level (78 ± 35 min and 40 ± 12 min, respectively, vs 223 ± 48 min in control studies). In contrast, the caecal stimulation triggered by IL‐1β was not only blocked by prazocin and yohimbine (1 mg kg−1i.p.), but also by sulpiride (1 mg kg−1i.p.) and granisetron (1 mg kg−1i.p.). This study confirms that IL‐1‐induced changes in small and large intestinal motility are expressed through two separate pathways. We can suggest that mediators acting to modulate CRF release, such as catecholamines through α1and α2receptors, dopamine through D2receptors, and serotonin through 5HT3receptors, could be involved in the caecal stimulation. PG‐dependent changes in the jejunal motility pattern seem to be li

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00183.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractWe examined the possible involvement of 5‐HT4receptors in the gastroprokinetic effects of mosapride citrate (AS‐4370). In isolated longitudinal muscle myenteric plexus (LMMP) preparations from the guinea‐pig ileum, mosapride, cisapride, zacopride and metoclopramide enhanced electrically evoked contractions with EC50values of 74.2, 32.2, 50.3 and 1047.4 nM, respectively. The maximal increases in the amplitude of the contractions caused by mosapride, cisapride, zacopride and metoclopramide were 58, 78, 100 and 92% of those caused by 5‐HT, respectively. The enhancing effect of mosapride was non‐surmountably antagonised by high concentrations of tropisetron (10−‐7–3 ± 10−‐6M), but not by methysergide (10−‐6M) or ondansetron (10−‐6M). In the ileal LMMP preparations, mosapride, cisapride, zacopride and tropisetron had an inhibitory effect related to concentration on the 5‐HT (3 ± 10−‐7M) induced contractions with IC50values of 0.59, 0.71, 0.55 and 7.9 μM, respectively. Mosapride (10−‐8‐−10−‐5M) alone, unlike cisapride and zacopride, did not cause contraction in the ileal LMMP preparations. These results suggest that mosapride is a partial 5‐HT4receptor agonist and possesses 5‐HT4receptor antagonist activity at high concentrations. In conscious dogs with force transducers implanted, mosapride (I mg kg−1, i.v.) enhanced the antral motor activity in the postprandial state, and this enhancement was clearly antagonised by a high dose of tropisetron (10 mg kg−1h−1, i.v. infusion) that did not affect basal motor activity, indicating the involvement of 5‐HT4r

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00184.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractErythromycin mimics the effects of motilin but its action on colonic motility is still controversial. The aim of this study was to evaluate the effect of intravenous infusions of various doses of erythromycin on colonic motility in patients with irritable bowel syndrome (IBS).At 09.00 hours, day 1 (D1), an intraluminal probe was introduced up to the right colon in 24 IBS patients with myoelectrical activity recorded for 48 h. Patients were randomised in three groups of eight, receiving either erythromycin 1.5, 3 or 7 mg kg−1. All were investigated as follows: at 09.00 hours, D2, fasted patients were infused with erythromycin in 30 min; at 09.00 hours, D3, glycerol 10 ml was injected intraluminally. Colonic activity was measured 30 min before the infusion started, during and 30 min after it, separately in the left and right colons, and expressed in time occupied during the recording period.Basal activity was similar in both parts of the colon. During and after erythromycin 1.5 and 3 mg kg−1, colonic activity remained unchanged. Erythromycin 7 mg kg−1induced a moderate increase in spiking activity (long spike bursts or LSBs + 33%; migrating LSBs or MLSBs + 41%) in the right colon, no change being statistically significant; activities in the left colon were similar to basal level.During the first 30 min following glycerol injection, mean short spike burst or SSB activity did not change, mean LSB activity increased by seven fold (P = 0.014) and MLSB activity by ten fold (P = 0.023).Erythromycin at doses from 1.5 to 7 mg kg−1failed to stimulate colonic motility in IBS patients. By contrast, response to glycerol was strong, suggesting normal colonic responsiveness. Erythromycin stimulatory effects could be limited to the upper gut at least in IBS p

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractOur hypothesis was that manometry in the colon was less sensitive than the electronic barostat in detection of colonic contractions. In ten healthy volunteers, we have characterised the pressure activity and tone of the colon by means of combined multilumen manometry and a barostatic balloon that was infinitely compliant, conformed to the colon's inner wall, and was clamped at a constant ‘operating’ pressure throughout the study. A computer program separated indices of the colon's motor function detected by the barostat: a baseline volume and phasic volume events. The barostat detects on average 70% more phasic pressure events than manometric sideholes located 2 em proximal to 7 cm distal to the balloon. Manometry becomes less sensitive than the barostat when the colonic diameter exceeds 5.6 em. The barostat detects on average 90% of all propagated and non‐propagated (>30 mmHg) manometric peaks. The baseline volume changes significantly after the ingestion of a 1000‐kcal meal, consistent with an increment in colonic tone, undetected by manometry. A combined barostat—manometry assembly appears to be preferable to manometry alone in the intraluminal evaluation of human colonic pressure activity

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAntisera against neuron specific enolase (NSE), calbindin and the neuropeptides substance P (SP), vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), enkephalin (ENK) and somntostatin (SOM) were used to demonstrate the presence of nerve fibres and cell bodies in the small intestine of the black‐capped capuchin, Cebus appela. NSE‐immunoreactive (IR) nerve fibres werefoundin all layers of the intestinal wall, except the longitudinal muscle, and immuno‐reactive nerve cell bodies were found in both myenteric and submucous plexuses. The submucous plexus was composed of external and internal ganglionated plexuses. Endocrine cells in the epithelium were reactive for NSE. In ganglia of the myenteric plexus, SP‐, VIP‐, ENK‐, SOM‐, NPY‐ and calbindin‐IR varicose and non‐varicose fibres were found around reactive and unreactive cell bodies. Calbindin, ENK‐, SP‐, SOM‐ and VIP‐IR, but not NPY‐IR, nerve cell bodies were observed. The primary and secondary plexuses contained fibres of each type examined. The tertiary plexus was rich in SP‐IR fibres, although ENK‐, NPY‐, SOM‐ and VIP‐IR fibres were also observed. The deep muscular plexus had mainly ENK‐ and SP‐IR fibres and few VIP‐IR fibres, while in the remainder of the circular muscle VIP‐IR fibres predominated. There were few SP‐IR and no ENK‐IR fibres in this layer. The two ganglionated plexuses of the submucosa contained ENK‐, NPY‐, SOM‐, SP‐ and VIP‐IR fibres, but calbindin‐IR fibres were not found. SP‐ and VIP‐IR cell bodies were found in both plexuses. Blood vessels had SP‐, VIP‐ and NPY‐IR fibres around them. SP‐, VIP‐ and a few SOM‐IR pbres innervated the mucosa, while endocrine cells were found with SP‐, SOM‐ and NPY‐IR. The present study demonstrated that the distribution of the neuropeptides SP‐ and VIP‐IR is similar in the small intestine of the black‐capped capuchin to that in the dog, guinea pig, human and rat. SP‐ and VIP‐IR possibly mark neurons of the same function in each s

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractRegional differences in biomechanical properties of the oesophagus were studied in seven healthy Goettingen minipigs by means of impedance planimetry. The investigation was done during anaesthesia by stepwise pressure‐induced balloon distensions with concomitant measurement of pressure and luminal cross‐sectional area (CSA) in the oesophagus 5, 10 and 15 em above the gastro‐oesophageal junction (GEJ). The compliance and wall tension were computed from measurements of the pressure and steady‐state CSA. Probably due to the anaesthesia, only scant peristalsis was recorded and the CSA always reached steady state during balloon distension. The CSAs were highest in the distal oesophagus (P<0.01). At the highest induced pressure, the figures were 665 ± 57, 529 ± 50 and 452 ± 47 mm2for the locations 5, 10 and 15 cm from the GEJ, respectively. Hysteresis did not differ between the measuring points. The oesophagus was significantly more compliant at low pressures (1–3 kPa) 5cm above the GEJ compared to the more proximally located measuring points(P<0.05).In conclusion, regional variations occurred in passive biomechanical properties of the oesophagus with the highest distensibility occurring 5 cm a

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00189.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA brief account of the aquisition of knowledge of the enteric nervous system and the ways in which technological developments have contributed to analysis of the reflex circuits is presented. The review concentrates on the motility controlling circuits in the small intestine of the guinea‐pig, where much more is known than for any other region or species. In this region, the basic circuit is known. Primary sensory neurons connect monosynaptically to motor neurons, and also make connections via chains of interneurons, which in turn provide outputs to the motor neurons. The ascending excitatory and descending inhibitory reflexes are manifested through these circuits. Sufficient details of the functions and connections of all neuron classes are available to permit activity in the reflex pathways to be realistically simulated in a computer model, which is briefly describe

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1994.tb00190.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY