共查询到20条相似文献,搜索用时 15 毫秒
1.
Einar Husebye MD Viggo Skar PhD Odd O. Aalen PhD Magne Osnes PhD 《Digestive diseases and sciences》1990,35(9):1057-1065
A new technique for ambulatory manometry of the small intestine with digital storage of signals is presented. Postprandial motility after a 1700-kJ meal and nighttime fasting motility were recorded in 19 healthy young adults. A comprehensive statistical approach was worked out to illuminate the statistical properties of fasting motility data from long-term studies. Separate quantifications of the variation within and between individuals are presented for the migrating motor complex (MMC). The overall mean for the MMC period was 107 min, with incomplete periods included as censored data. Standard deviation within individuals was 49 min, and standard deviation between individuals 16 min. Presented in the same manner, phase III in the proximal jejunum lasted 5.3 min, with standard deviations of 1.5 and 1.1 min, respectively. The propagation velocity of phase III in the distal duodenum was 10.8 cm/min, with standard deviations of 3.7 and 4.1 cm/min, respectively. Fed-state lasted 324±110 min (mean±sd), and adjusted fed-state, an alternative definition proposed in this study, 290±80 min. This variance component model, extended to handle censored data, provides a useful statistical approach for the analyses of the MMC. The MMC period proved to be less suitable for quantitative comparisons because of dominating intraindividual variance. Comparisons presented indicate that discrepancies in reference values depend, to a great extent, on the statistical methods applied.This study was supported by grants from the Norwegian Medical Research Council and Helga Sembs Foundation. 相似文献
2.
Summary The effects of hyperglycaemia on postprandial small intestinal motor activity are unclear. Duodenal and jejunal pressures and duodeno-caecal transit were measured in eight healthy male volunteers during euglycaemia (blood glucose 4–6 mmol/l) and hyperglycaemia (blood glucose 12–15 mmol/l). Duodenal and jejunal pressures were recorded with a manometric assembly during intraduodenal infusion of 100 ml nutrient liquid comprising 14% protein, 31.5% fat and 54.5% carbohydrate together with 15 g lactulose. Duodeno-caecal transit was determined by a breath hydrogen technique. The number of duodenal (p<0.05) and jejunal (p<0.01) pressure waves, excluding phase III episodes was reduced during hyperglycaemia compared to euglycaemia. Hyperglycaemia was associated with earlier onset of phase III activity (30±12 vs 132±20 min; p<0.05). Duodeno-caecal transit was slower during hyperglycaemia when compared to euglycaemia (114±17 vs 49±6 min, p<0.01). We conclude that induced hyperglycaemia has major effects on postprandial small intestinal motility. The reduction in duodenal and jejunal motor activity is likely to explain the retardation of small intestinal transit during hyperglycaemia.Abbreviations TMPD
Transmusocal potential difference
- MMC
migrating myoelectric complex 相似文献
3.
Dr. Heinz Pernthaler MD Alfons Kreczy MD Robert Plattner MD Gabriele Pfurtscheller MD Leopold Saltuari MD Thomas Schmid MD Dietmar Öfner MD Günther Klima MD Raimund Margreiter MD 《Digestive diseases and sciences》1994,39(6):1216-1221
The effect of rejection on myoelectric activity of an orthotopically transplanted small intestinal segment (group I,N=14) was studied. Electrodes were placed on grafts and recipient small bowel. Isografts (group II,N=5) and native bowel (group III,N=5) served as controls. The first morphological signs of rejection were seen on day 6 and steadily progressed until day 11, when the cellular infiltrate involved all layers of the bowel wall. Slow-wave frequencies remained unchanged throughout the observation period. No difference was detectable between grafts (group I: 31.9±1.65; group II: 31.36±0.7) and native bowel after transection (group I: 32.16±1.78; group II: 31.50±1.01), which was different (P=0.0001) from intact bowel of group III animals (38.4±0.81). Irregular MMCs were detectable in grafts from day 5 on and replaced after food intake by random spiking activities. At day 8, spiking activities disappeared in allografts, which showed a still preserved mucosal architecture, while slow-wave activities continued. These findings demonstrate that intestinal allografts during rejection develop paralysis before mucosal destruction is established, which might be of clinical relevance. 相似文献
4.
Tommy Tollström MD Per M. Hellström MD PhD Catja Johansson MD PhD Bengt Pernow MD PhD 《Digestive diseases and sciences》1988,33(5):552-557
Interdigestive motility of the small intestine was examined in 23 fasted healthy volunteers following luminal administration of the prostaglandins E2 and F2. Motility was monitored by means of water-perfused catheters measuring intraluminal pressure changes. The registration points were located 25 cm apart, in the proximal duodenum, at the angle of Treitz, and in the jejunum. Prostaglandin E2 administered intraduodenally delayed the initiation of the subsequent activity front. The interval to the next activity front was prolonged by a dose of 1.0 mg prostaglandin E2 from 79.5±9.5 min to 137.1±5.0 min (P<0.01) and to 158.0±14.0 min by 2.0 mg prostaglandin E2 (P<0.05). Also, in four of seven experiments, a progressing activity front was arrested by 2.0 mg prostaglandin E2. Prostaglandin F2 at 2.5 or 5.0 mg given intraduodenally induced bursts of contractions with a frequency of 17.7± 0.8 contractions per minute and an amplitude of 10 to 110 mm Hg (P<0.07). In comparison, food intake produced irregular contractions at a frequency of 5.3± 1.8 contractions per minute and an amplitude of 10 to 50 mm Hg (P<0.05). It is concluded that prostaglandin E2 delays the initiation of activity fronts in the duodenum. In contrast, prostaglandin F2 changes the interdigestive motility pattern to one of intense contractile activity, which is different from the postprandial motility pattern. 相似文献
5.
Dr. Gordon L. Telford MD Michael A. Nemeth MD Sushil K. Sarna PhD M. Scott Harris MD Krishnamurthy Ramaswamy PhD Wolfgang H. Schraut MD Kenneth K. W. Lee MD Christopher P. Johnson MD Susan Walgenbach-Telford PhD 《Digestive diseases and sciences》1996,41(6):1082-1087
The effect of transplantation on small intestinal absorption, digestive capacity, myoelectric activity, and morphology was assessed in inbred Lewis rats. Electrodes were sutured to the duodenum and isografted jejunoileum or to the native jejunoileum in controls. The frequency of migrating myoelectric complexes (MMCs) in the duodenum was 3.3±0.3/hr in controls and 1.8±0.4/hr in transplants (P<0.05). MMC frequency in the jejunoileum was 5.1±1.3/hr in controls and 3.2±0.9/hr in transplants (P>0.05). MMCs appeared to migrate from the duodenum to the jejunoileum 80±3% of the time in controls and 59±7% of the time in transplant rats (P<0.05). Absorption in the transplanted jejunoileum demonstrated a 35–40% decrease in glucose and electrolytes absorption. Villus height and number of nuclei per villus was reduced. Intestinal length (dry) was 103±6 cm for controls and 51±3 cm for transplant rats (P<0.05). Brush border sucrase activity was unchanged. We conclude that small intestinal isografts display similar myoelectric activity as controls, but the decreased absorptive capacity and villus height may require longer segments of intestine to be transplanted in order to support normal nutrition.Supported by the Veterans Administration Research Service. 相似文献
6.
《Scandinavian journal of gastroenterology》2013,48(8-9):920-926
Abstract Objective. Patients with cystic fibrosis (CF) often suffer from gastrointestinal (GI) dysfunction including obstructive symptoms, malabsorption and pain, but the underlying pathophysiology remains obscure. Aim. To compare GI motility and transit times in CF patients and healthy controls. Material and methods. Ten CF patients (five women, median age 23) with pancreatic insufficiency were studied. Total gastrointestinal transit time (GITT) and segmental colonic transit times (SCTT) were assessed by radiopaque markers. Gastric emptying and small intestinal transit were evaluated using the magnet-based motility tracking system (MTS-1). With each method patients were compared with 16 healthy controls. Results. Basic contraction frequencies of the stomach and small intestine were normal, but the pill reached the cecum after 7 h in only 20% of CF patients while in 88% of controls (p = 0.001). Paradoxically, velocity of the magnetic pill through the upper small intestine tended to be faster in CF patients (median 1.1 cm/min, range 0.7–1.7) compared with controls (median 1.0 cm/min, range 0.6–1.7) (p = 0.09). No statistically significant differences were found in median gastric emptying time (CF: 58 min, range 6–107 vs. healthy: 41 min, range 4–125 (p = 0.24)), GITT (CF: 2 days, range 0.5–3.3 vs. healthy: 1.5 days, range 0.7–2.5 (p = 0.10)), right SCTT (CF: 0.5 day, range 0–1.1 vs. healthy: 0.4 day, range 0–1.0 (p = 0.85)), or left SCTT (CF: 1.0 day, range 0–2.2 vs. healthy 0.6 day, range 0.2–1.2 (p = 0.10)). Conclusions. In spite of normal contraction patterns, overall passage through the small intestine is significantly delayed in CF patients while upper small intestinal transit may be abnormally fast. 相似文献
7.
小肠常见炎症性溃疡性疾患35例的X线诊断 总被引:2,自引:0,他引:2
目的分析小肠常见炎症性溃疡性疾患的 X 线表现.方法 35例小肠炎症性溃疡性疾患,男20例,女15例.其中肠结核11例,Corhn 病13例,肠 Behcet 病7例,单纯性溃疡和缺血性肠炎各2例.33例有病理结果,2例经临床治疗证实.结果病变局限于回肠,肠结核11例中有9例,Corhn 病13例中有10例,肠 Behcet 病7例中有5例,单纯性溃疡2例中有l例,2例缺血性肠炎均在回肠.部分病例累及回盲部.35例均有溃疡,形态表现多种多样,但纵行溃疡和裂隙仅见于 Crohn 病.大而深的溃疡5例,3例为肠 Behcet 病.浅而不规则溃疡13例,10例见于肠结核.横行溃疡2例均见于肠结核.结论肠溃疡的形态、周围粘膜的变化和肠管变形等 X 线特征是各种疾患的诊断依据.强调正确的诊断决定于良好的 X 线检查技术和对形态变化的正确解释. 相似文献
8.
黄芪对狗小肠血流量和运动的影响 总被引:4,自引:0,他引:4
目的了解黄芪煎液对小肠血流量和运动的影响.方法采用不同浓度(10%,30%及50%)的黄芪煎液置入10条健康杂交狗的空肠中,运用电磁血流计和压力传感器观测其对小肠血流量和运动的影响.并以生理盐水作为对照进行了对比观测.结果将黄芪煎液置于在体狗小肠后,小肠血流量(ml·min-1·100g-1)增加,高达5485±1186~7355±1240,与生理盐水组4256±934~4315±1023相比较差异有显著性(P<005)或高度显著性(P<001);小肠平滑肌张力(kPa)增强,高达070±027~095±039,与生理盐水组044±021~051±022相比较差异有显著性(P<005);小肠蠕动振幅(mv)增高,高达1053±237~1204±337,与生理盐水组652±231~644±218相比较,差异有显著性(P<005).结论黄芪具有促进小肠消化功能的作用,不同浓度的黄芪煎液对小肠的作用存在着一定的差异. 相似文献
9.
Orogastric feeding of a charcoal meal to rats was employed to measure whether the various stages of pregnancy could influence gastrointestinal transit. The oestrous cycle of female Sprague-Dawley rats was checked daily. If pro-oestrus occurred, the first day of pregnancy was defined to be on the next day after the copulation. Gastrointestinal transit studies were conducted on day 7 (first trimester), day 14 (second) and day 21 (third), respectively. The rats were killed 15 min after the successful feeding of a calorie-free, charcoal-containing test meal via a transiently placed orogastric catheter. Gastrointestinal transit was defined as the per cent of charcoal transit divided by the total length of the small intestine. These results were compared with the data obtained from non-pregnant female rats. Mean percentages of transit for the first, second and third trimester, and for controls were 42.8 ± 1.9, 45.3 ± 4.1, 35.7 ± 1.7 and 42.6 ± 1.4%, respectively (mean ± s.e.). Late pregnancy elicited a marked inhibition of transit (P < 0.01). A significant negative correlation between transit and uterine weight of all pregnant rats was seen (r= -0.50, P < 0.05). The present study indicates that inhibited gastrointestinal transit occurs in the late pregnant rat. 相似文献
10.
Dr. D. A. Gorard MD G. W. Libby M. J. G. Farthing MD 《Digestive diseases and sciences》1995,40(1):86-95
Antidepressants are used in irritable bowel syndrome (IBS) and may have effects on the gut independent of improving mood. We have investigated the actions of a tricyclic antidepressant on small intestinal motor function in eight healthy volunteers and in six patients with diarrhea-predominant IBS. Fasting ambulatory motility was recorded from six small intestinal sites for 16–18 hr while on no drug (baseline) and while taking imipramine for five days. Orocecal transit time (OCTT) was measured by lactulose hydrogen breath test, during baseline and imipramine administration. Imipramine did not alter migrating motor complex periodicity, but slowed jejunal phase III propagation velocity in controls from 7.5±1.1 to 3.6±0.5 cm/min (P<0.01) and in IBS from 7.8±0.6 to 4.4±0.5 cm/min (P<0.0001). Phase III duration at each site was increased, and total recorded phase III was greater during imipramine than baseline studies. Imipramine increased the amplitude of phase III contractions. There was no effect of imipramine on non-phase-III motility index or discrete clustered contractions. Imipramine prolonged OCTT from 73±6 min to 97±8 min in controls (P<0.05) and from 61±9 min to 89±8 min in IBS (P<0.05). Although OCTT was shorter in this IBS group, no motility differences were seen between controls and IBS. This demonstration that a tricyclic antidepressant can modify small intestinal motor function in health and in IBS supports the view that these drugs may have therapeutic actions in IBS unrelated to mood improvement.This work was supported by the Priory Hospitals Group. 相似文献
11.
小肠受特殊解剖位置以及检测手段的限制,小肠运动功能的研究相对滞后,尤其是对小肠MMC的病理生理功能缺乏全面的了解。研究证实小肠动力异常与细菌过度生长和慢传输性便秘等有关。十二指肠内酸和脂肪、葡萄糖的吸收对小肠动力均有影响。同时神经体液等因素对小肠动力也有调节作用。 相似文献
12.
13.
Chronic diarrhea may occur when gastrointestinal transit is abnormally rapid. We hypothesized that oleic acid given prior to a meal would slow gastrointestinal transit and reduce diarrhea by activating nutrient-triggered inhibitory feedback mechanisms in the small intestine. Transit time was measured in eight normal subjects following ingestion of a control emulsion (0 ml oleic acid), and in 45 patients with chronic diarrhea following ingestion of emulsions containing 0, 1.6, and 3.2 ml oleic acid. Stool volume and frequency on and off treatment were compared. Transit time in normal subjects was 102.4 ± 11.2 min (mean ± se). Transit times in patients was shorter at 29.3 ± 2.8 min with the 0-ml dose (P < 0.001), but increased to 57.2 ± 4.5 min with the 1.6-ml dose and to 83.3 ± 5.2 min with the 3.2-ml dose (P < 0.001). In the 18 patients who provided stool records, frequency of bowel movements decreased from 6.9 ± 0.8 to 5.4 ± 0.9 bowel movements/24 hr (P < 0.05) and stool volume decreased from 1829.0 ± 368.6 to 1322.5 ± 256.9 ml/24 hr with treatment (P < 0.05). An emulsion containing oleic acid slowed gastrointestinal transit and reduced diarrhea by activating nutrient-triggered inhibitory feedback mechanisms in the small intestine. 相似文献
14.
丹参对移植小肠微循环的保护作用 总被引:1,自引:1,他引:1
目的观察保存液中加入丹参对低温保存小肠微循环的保护作用.方法杂种猪12只,随机分成2组,对照组(n=6),供肠采用Eurocolins(EC)液保存;丹参组(n=6),EC液中加入丹参注射液(20mg/L),二组供肠均4℃保存24h后自体移植.观察移植小肠组织损伤和肠粘膜伊文思蓝渗出量(微循环通透性).结果再灌注05h丹参组肠粘膜组织损伤评分低于对照组(320±042vs465±055,P<005),微循环通透性(μg/g湿重)较低(13675±0542vs20406±0459,P<001).结论丹参能有效地抑制低温保存小肠微循环通透性的增加,减轻血管内皮细胞损伤. 相似文献
15.
AIMS: To evaluate the diagnostic yield and safety of a new push type videoenteroscope (PVE) for diagnosis of small bowel disease. METHODS: Three hundred and thirteen patients were referred for one or two way PVE from December 1993 to June 1996. Indications for PVE were: an unexplained iron deficiency anaemia with or without clinically evident gastrointestinal bleeding; or a complementary investigation for suspected small bowel disease, after a small bowel barium follow through (SBBFT) considered as normal or abnormal, but without a definite diagnosis. RESULTS: A jejunoscopy and a retrograde ileoscopy were carried out in 306 and 234 patients, respectively. In patients with isolated anaemia (n = 131) and those with clinically evident gastrointestinal bleeding associated anaemia (n = 72), PVE provided a diagnosis in 26 (19.8%) and 22 (30.5%) cases, respectively. Lesions found were located in the jejunoileum in 30 (14.7%) patients and in the gastroduodenum or the colon in 18 (8.8%) patients--that is, within the reach of the conventional gastroscope/colonoscope. In patients with normal (n = 54) or abnormal (n = 56) SBBFT, PVE provided a diagnosis in 17 (31%) and 27 (48%) cases, respectively. In 25% of cases, the abnormal appearance of SBBFT was not confirmed. The site of the radiological abnormality was not reached in 27% of cases. Lesions were located at the jejunum and the ileum in 59 (64%) and 33 (36%) cases, respectively. CONCLUSIONS: PVE is useful in around 30% of cases of unexplained anaemia or after an SBBFT which failed to provide an accurate aetiological diagnosis. Use of retrograde videoenteroscopy increases diagnostic yield by one third. 相似文献
16.
Evidence that nitric oxide mechanisms regulate small intestinal
motility in humans 总被引:20,自引:1,他引:19
Background—Non-cholinergicnon-adrenergic neural mechanisms involving nerves containing NO havebeen shown to modulate smooth muscle in the gastrointestinal tract, andit has been suggested that release from tonic NO inhibition may beimportant in the regulation of cyclical fasting small intestinal motility.
Aims—To evaluate therole of NO mechanisms in the regulation of fasting small intestinalmotor activity in humans using a specific NO synthase inhibitor,NG-monomethyl-L-arginine( L-NMMA).
Methods—In sevenhealthy male volunteers, duodenal and jejunal pressures were measuredfor four hours with a nine lumen manometric catheter. Volunteersattended on four separate days on which they received an intravenousinfusion of either saline or L-NMMA (0.5, 2, or 4 mg/kg/h)in random order. Intravenous infusions began 10 minutes aftercompletion of phase III of the migrating motor complex (MMC).
Results—The firstepisode of phase III activity occurred earlier after infusion of 2 and4 mg/kg/h L-NMMA than after infusion of 0.5 mg/kg/hL-NMMA or saline (mean (95% confidence interval) 52 (36-68) and 57 (18-97) v 116 (69-193) and145 (64-226) minutes respectively) with a resultant MMC cycle lengthof 82 (59-105) and 86 (46-126) v 132 (49-198) and 169 (98-240) minutes respectively. The total number ofphase III activities during the four hour recording was increased(p<0.05) by L-NMMA at a dose of 4 mg/kg/h (2 (1-3)) butnot at 2 mg/kg/h (1.5 (1-2)) or 0.5 mg/kg/h (1.3(1-2)) compared withsaline (1.3 (0.6-2)). L-NMMA had no effect on theduration, velocity, number of contractions per minute, length ofmigration, or site of origin of phase III of the MMC. The duration ofphase I activity was shorter (p<0.05) with 4 mg/kg/h L-NMMA than with saline (12 (1-23)v 31 (19-44) minutes).
Conclusions—Theseobservations suggest that NO mechanisms play a role in the regulationof fasting small intestinal motor activity in humans.
Aims—To evaluate therole of NO mechanisms in the regulation of fasting small intestinalmotor activity in humans using a specific NO synthase inhibitor,NG-monomethyl-L-arginine( L-NMMA).
Methods—In sevenhealthy male volunteers, duodenal and jejunal pressures were measuredfor four hours with a nine lumen manometric catheter. Volunteersattended on four separate days on which they received an intravenousinfusion of either saline or L-NMMA (0.5, 2, or 4 mg/kg/h)in random order. Intravenous infusions began 10 minutes aftercompletion of phase III of the migrating motor complex (MMC).
Results—The firstepisode of phase III activity occurred earlier after infusion of 2 and4 mg/kg/h L-NMMA than after infusion of 0.5 mg/kg/hL-NMMA or saline (mean (95% confidence interval) 52 (36-68) and 57 (18-97) v 116 (69-193) and145 (64-226) minutes respectively) with a resultant MMC cycle lengthof 82 (59-105) and 86 (46-126) v 132 (49-198) and 169 (98-240) minutes respectively. The total number ofphase III activities during the four hour recording was increased(p<0.05) by L-NMMA at a dose of 4 mg/kg/h (2 (1-3)) butnot at 2 mg/kg/h (1.5 (1-2)) or 0.5 mg/kg/h (1.3(1-2)) compared withsaline (1.3 (0.6-2)). L-NMMA had no effect on theduration, velocity, number of contractions per minute, length ofmigration, or site of origin of phase III of the MMC. The duration ofphase I activity was shorter (p<0.05) with 4 mg/kg/h L-NMMA than with saline (12 (1-23)v 31 (19-44) minutes).
Conclusions—Theseobservations suggest that NO mechanisms play a role in the regulationof fasting small intestinal motor activity in humans.
Keywords:nitric oxide (NO); small intestine; motility; migrating motor complex (MMC)
相似文献17.
Clemens CH Samsom M Van Berge Henegouwen GP Smout AJ 《Digestive diseases and sciences》2003,48(1):74-82
Our objective was to evaluate left colonic motility patterns recorded under physiological conditions during 24 hr in fully ambulant nonconstipated IBS patients compared to healthy controls. A 42-hr manometry of the left colon was performed in 11 nonconstipated IBS patients and 10 age- and sex-matched healthy volunteers. On day 1, a 6-channel, 10-cm interval, solid-state catheter was positioned. Frequency, amplitude, and motility index (MI) of segmenting pressure waves in the descending and sigmoid colon were calculated during the 24-hr study period on day 2. High-amplitude propagated contractions (HAPCs) were identified visually and their characteristics were calculated. In IBS patients a higher frequency of segmenting pressure waves was observed in the sigmoid colon compared to the descending colon (P = 0.006). In contrast, no regional differences were observed in controls. Awakening (P = 0.048) as well as having a meal (P = 0.024) was associated with a smaller increase of contraction frequency in the descending colon of IBS patients compared to controls. HAPCs occurred more frequently in IBS patients than in controls (P = 0.035$). HAPCs in IBS patients reached a more distal colonic level and occurred more frequently in clusters. Defecation in IBS patients, but not in controls was always preceded by a cluster of HAPCs. In conclusion, left colonic segmenting pressure waves and HAPC characteristics are altered in nonconstipated IBS patients. 相似文献
18.
Neuromuscular and vascular hamartoma of the small bowel 总被引:1,自引:0,他引:1
Edward M. Kwasnik MD Steven R. Tahan MD Jeffrey A. Lowell MD Barbara Weinstein MD 《Digestive diseases and sciences》1989,34(1):108-110
Summary Neurovascular and muscular hamartoma is an unusual benign neoplasm of the small intestine. The clinical and pathological features of this lesion, which we recently encountered in a 91-year-old male, are the subject of this report and are discussed in the context of previously described cases. 相似文献
19.
目的 了解健康中国人食管动力对不同食团的反应.方法 对经过严格入选排除标准入选的18名受试者行高分辨率测压(HRM),分析静息及不同食团(5 ml、10 ml、15 ml、20 ml水、黏胶及固体食团)吞咽时的食管动力特点.结果 固体吞咽时,蠕动起始速度(2.5±0.4)cm/s均低于其他各种类型食团(水及黏胶),近段压力(74.6±7.2)mmHg均高于其他各种类型食团;固体吞咽时食管体部蠕动速度和食管各段收缩幅度与黏胶吞咽时比较均有差异.在各种形态食团的吞咽中,食管远段的压力总是高于近段,在5 ml、10 ml湿咽、黏胶吞咽和固体吞咽时,食管远段压力高于中段.5 ml液体吞咽及黏胶吞咽时,近段压力女性低于男性;10ml与20ml湿咽时,女性食管蠕动速度均低于男性.结论 不同食团诱发的食管蠕动速度和幅度是不同的,性别差异在食管蠕动速度及不同节段收缩幅度上无一致性结果. 相似文献
20.
Merle A Delagrange P Renard P Lesieur D Cuber JC Roche M Pellissier S 《Journal of pineal research》2000,29(2):116-124
Melatonin is synthesized during the night by the pineal gland. Recently, melatonin binding sites have been identified in the gut. Despite few studies, the physiological role of melatonin in gut function remains unclear. The objective of the present study was to investigate the effects of melatonin in the regulation of intestinal motility by using the melatonin receptor antagonist S 22153 in rats. Twenty-four male Wistar rats (400 +/- 25 g) were equipped with intraparietal electrodes along the small intestine. Rats were subjected to a 12:12 hr light:dark schedule. During the dark phase, intestinal migrating motor complexes (MMCs) frequency increased (P < 0.05) by 20% in the duodenum and in the jejunum compared with daylight. This effect is due to a significant reduction in the irregular spiking activity (ISA) of MMCs. Concurrently, at night, the duration of the postprandial motor response is reduced by 30% in the duodenum and 50% in the jejunum and ileum. The administration of S 22153 (2 mg/kg sc) at night suppressed these nocturnal variations and restored the daylight values. In contrast, S 22153 was ineffective during daylight whatever the digestive state. Administration of melatonin (1 mg/kg iv) during the preprandial state, 3 hr after light onset, decreased (-80%) the duration of the ISA of MMCs at the three intestinal levels. During the satiety phase, melatonin administered 10 min before or 15 min after food onset induced the appearance of a transitory preprandial-like motor profile in the entire small intestine. In contrast, when administered at the end of the meal it was ineffective. Preprandial and postprandial melatonin effects were prevented by S 22153 pretreatment. In conclusion, these findings reveal, first, that endogenous melatonin is physiologically involved in the pre- and postprandial changes of intestinal motility at night. Second, exogenous melatonin produces pharmacological effects on pre- and postprandial intestinal motility. In both cases, the action of melatonin corresponds to an inhibition of ISA and a reinforcement of the cyclic MMC pattern. 相似文献