摘要:

AbstractWe examined the effects of bowel manipulation on mast‐cell number and function in the rat. Mast cells were assessed histologically and by their ability to induce muscle contraction. Anaesthesia or abdominal incision did not alter mast‐cell number. However, laparotomy plus brief exteriorization of jejunal segments significantly increased mast‐cell number. Applying saline to the serosal surface by swab or droplet application increased mast‐cell number 16‐ and 3‐fold, respectively. Saline swabbing of jejunal segments from rats previously infected with Trichinella significantly reduced mast‐cell number. Functional integrity of mast cells was illustrated by muscle contraction in vitro following compound 48/80 or antigen and inhibition of cromoglycate. Serosal application of compound 48/80 in vivo increased mast‐cell number. This increase in mast‐cell number by compound 48/80 or by saline was prevented by prior treatment with cromoglycate. These data suggest that mast‐cell degranulation underlies the manipulation‐induced masto

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00101.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractDiurnal changes in canine colonic motility were investigated by means of chronically implanted force transducers. A characteristic of the colonic motor profile in the fasted state was the occurrence of colonic motor complexes consisting of tonic contractions superimposed with phasic ones. On feeding, motor complexes were immediately induced in the whole colon and continued to occur at significantly shorter intervals than those in the fasted state, but the duration and the amplitude of the colonic motor complexes were not affected by feeding. This increased activity period lasted for 8–16 h after feeding, and 83.3% of the defecations were observed in this period. Of the defecations 33% occurred in the first 2 h after feeding (P<0.05). More than 80% of the giant migrating contractions associated with defecation propagated from the middle to the distal colon, and the start of faeces evacuation coincided with the end of the relaxation period of the distal colon preceding the arrival of the giant migrating contractions. More than 90% of the giant migrating contractions not associated with defecation migrated from the proximal to the middle colon. More than 60% of the colonic motor complexes migrated in an aboral direction and about 18% of them in an oral direction. These results suggest that (1) defecations tend to occur immediately after feeding; (2) the regional distribution of giant migrating contractions was different between those associated and not associated with defecatio

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00102.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effect of several calcium antagonists on acetylcholine‐induced contractions has been examined in longitudinal smooth muscle strips from sheep duodenum. Contractions induced by 10−5M acetylcholine were inhibited up to 65% in Ca2+‐free solution and were blocked in the absence of extracellular Ca2+plus 1 mM EGTA; 10 mM lanthanum reduced acetylcholine‐induced contractions by 97%: 105mverapamil and W−4mnifedipine reduced contractions by 58 and 42%, respectively, but sodium nitroprusside did not modify these responses: 10−4mtrifluoperazine inhibited acetylcholine‐induced responses by 75%: 10−2mcaffeine produced a contraction; 2 mmprocaine antagonized acetylcholine responses by 85%. We suggest that acetylcholine‐induced contractions were mediated by extracellular Ca2+that enters through a potential‐dependent Ca2+channel by intracellular Ca2+release, probably from sarcoplasmatic reticulum because procaine in

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00103.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractGiven the differences that normally exist in jejunal and Heal motility patterns, we wished to determine whether these regions respond differently to acute enteric infections. In 10 patients with acute gastroenteritis induced by Salmonella infection and 12 healthy individuals jejunal and Heal motility was recorded at eight equidistant sites by a manometric system for 6 h during fasting. All were healthy individuals, but only three of 10 patients exhibited the cyclic inter digestive motor complex; 82 ± 9 min duration in healthy individuals (mean ± SE). In the jejenum, patients exhibited short bursts of intense activity (6.3 ± 1.6 bursts/subject in patients vs. 1.8 ± 0.5 in controls; P<0.05); burst activity was scarce in the ileum. In contrast to healthy subjects, patients exhibited prolonged periods (64 ± 3 min duration) of Heal motor quiescence, that accounted for 32 ± 11% of recording time; such silent periods were not observed in the jejunum. Prolonged propagated ileal contractions were observed only in two healthy subjects, but in seven out of 10 patients. These data indicate that acute Salmonella infection magnifies the motor differences between the jejunum and the ileum; both regions generate aberrant and markedly different dysmotility pat

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00104.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractEffects of neurokinin A, neurokinin B, substance P and neuropeptide K on myoelectric activity in the small intestine were related to intestinal transit of a radioactive marker in fasted conscious rats. Myoelectric activity was recorded using bipolar electrodes implanted at 5, 20 and 35 cm distal to pylorus. Intravenous infusions of neurokinin A, neurokinin B and neuropeptide K at doses of 50–200 pmol kg−1min−1and substance P at doses of 100–300pmol kg−1min−1, disrupted migrating myoelectric complexes and induced irregular spiking. These effects were not prevented by atropine, hexamethonium or mepyramine. However, the effect of neurokinin A was attenuated by spantide. The irregular spiking induced by the tachykinins was associated with increased transit of the marker in animals receiving neurokinin A and neurokinin B, but not substance P and neuropeptide K. We conclude that the tachykinins activate the smooth muscle layers of the small intestine in the rat by mechanisms involving neurokinin receptors, but not muscarinic, nicotinic or H1‐receptors. Our results suggest a role for tachykinins in regulation of motility by induction of irregular spiking, which may stimulate transit through the sm

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00105.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractElectrogastrography is a non‐invasive method for recording gastric myoelectrical activity. The aims of this study were to record gastric myoelectrical activity in newborn infants using electrogastrographic methods and to compare frequency distributions of postprandial electrogastrograms (EGGs) recorded after gavage feedings. Nineteen infants with gestational ages ranging from 28 weeks to term were studied. Group I subjects were studied only after formula feedings (n = 15) and were divided by age into subgroups A, B and C: A (term, n = 4), B (33–36 weeks, n = 4), and C (28–32 weeks, n = 7). Group II infants (32–34 weeks, n = 4) were studied before and after gavage feeding. The percentage of total EGG power was calculated for four frequency ranges: 1–2.4 cpm (bradygastria); 2.5–3.6 cpm (normal range); 3.7–9.9 cpm (tachygastria); and 10–15 cpm (duodenal/respiratory). Results showed no significant differences in postprandial EGG power in these frequency ranges among the Group I infants of different gestational ages. The power in these EGG frequency ranges did not change significantly after gavage feedings in the Group II infants. In conclusion: (a) EGGs may be recorded successfully from preterm and term infants, (b) postprandial gastric myoelectrical activity in all frequency bands is similar among groups of premature and term infants, and (c) gavage feedings in premature infants did not increase 3 c

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00106.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effect of serotonin (5‐HT) and of more selective 5‐HT agonists on the peristaltic reflex evoked in the isolated guinea‐pig ileum was investigated. Using the Trendelenburg technique, peristaltic contractions were elicited by increasing intraluminal pressure, and rhythmic contractions of the longitudinal and circular muscle were measured after serosal administration of the drugs. 5‐HT potently stimulated contractions of the longitudinal muscle. The effect of 5‐HT was partly antagonized by the 5‐HT4receptor antagonist SDZ 205–557. Of the potent 5‐HT1Areceptor agonists, 8‐OH‐DPAT, 5‐carboxamidotryptamine (5‐CT) and dipropyl‐5‐CT (DP‐5‐CT), only 5‐CT caused a substantial stimulation. Of the 5‐HT1C‐/5‐HT2receptor agonists DOI and 5‐methoxytryptamine (5‐MeOT), DOI was inactive, whereas 5‐MeOT potently stimulated contractions. 5‐HT1Dreceptor agonists (5‐CT1sumatriptan) had a stimulatory effect. The effect of sumatriptan was antagonized by the 5‐HT1Dreceptor antagonist metitepine but not by the 5‐HT4receptor antagonist SDZ 205–557. The 5‐HT3receptor agonist 2‐methyl‐5‐HT and the antagonists ICS 205–930 and granisetron did not influence the peristaltic reflex. 6‐OH‐indalpine, a 5‐HT1Pagonist, was inactive. This data suggest that 5‐HT stimulates the peristaltic reflex in the isolated guinea‐pig ileum by activation of 5‐HT4‐ and 5‐HT1Dreceptors; other 5‐HT recep

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00107.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIntraluminal pressure and electrical activity of the colon of conscious dogs were recorded using silver bipolar electrodes and a pressure transducer. Two phases in the mechanogram of the transverse colon were observed: a quiescent phase (lack of contractions) lasting 12.05 ± 0.54 min and a contractile phase lasting 14.46 ± 0.88 min. The electrical activity was characterized by a quiescent phase (only slow waves in the electrogram) with a duration of 13.55 ± 1.73 min. Groups of spike potentials bursting in the rhythm of the slow waves appeared during the activity phase lasting 15.60 ± 2.02 min. Cholecystokinin octapeptide (CCK8) (10–20 ng/kg i.v.) significantly increased the duration of 1–3 active phases and shortened the duration of the quiescent phases. The percentage of slow waves with spike potentials during the active phase in the electro‐gram increased. Colonic contractions also increased, i.e. CCK8evoked an enhanced motility of the colon. Somatostatin (1–2 μg/kg i.v.) increased by two to three times the duration of the quiescent phases. Atropine (50–100 μg/kg i.v.) or somatostatin (1–2 μg/kg i.v.) inhibited both the spontaneous and the CCK8‐induced colonic motility. It is suggested that the inhibitory effect of somatostatin on spontaneous and CCAV induced colonic activity in conscious dogs is mediated by a decrease in cholinerg

ISSN:1350-1925    

DOI:10.1111/j.1365-2982.1993.tb00108.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY