Characterization of leukotriene actions on enteric neurons in the guinea-pig small intestine in vitro

2001 ◽  
Vol 120 (5) ◽  
pp. A535-A535
Author(s):  
S LIU ◽  
H HU ◽  
C GAO ◽  
N GAO ◽  
J WOOD
2001 ◽  
Vol 120 (5) ◽  
pp. A535
Author(s):  
Sumei Liu ◽  
Hong-Zhen Hu ◽  
Chuanyun Gao ◽  
Na Gao ◽  
Jackie D. Wood

1959 ◽  
Vol 197 (4) ◽  
pp. 926-928 ◽  
Author(s):  
T. Hastings Wilson ◽  
Elliott W. Strauss

Sacs of everted small intestine from a variety of animals were incubated in bicarbonate-saline containing vitamin B12 with and without intrinsic factor (IF). B12 uptake by rat intestine was stimulated only by its own intrinsic factor. Guinea pig ileum responded to all intrinsic factors tested (guinea pig, rat, hog, hamster, human being and rabbit). The intestines of hamster and rabbit were intermediate in specificity, responding to some, but not all, of the IF preparations. Species differences occur in both the intestine and intrinsic factor preparations. The guinea pig ileum was suggested as a possible assay for both hog and human IF.


2005 ◽  
Vol 100 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Michael K. Herbert ◽  
Rebecca Weis ◽  
Peter Holzer ◽  
Norbert Roewer
Keyword(s):  

1960 ◽  
Vol 198 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Elliott W. Strauss ◽  
T. Hastings Wilson

Sacs of everted small intestine were incubated in bicarbonate-saline containing radioactive vitamin B12 with or without a source of gastric intrinsic factor (IF). In both the hamster and guinea pig the lowest ileum was most active in B12 uptake in the presence of intrinsic factor, the upper jejunum showing little or no uptake. Low temperature and anaerobic conditions completely abolished the stimulatory effect of IF on B12 uptake. Intrinsic factor did not bind to the intestinal wall in the absence of B12 (even in the presence of calcium ion) as the IF activity could be completely removed by gentle washing of the tissue. The vitamin and intrinsic factor must be present together to cause intestinal uptake of B12.


2007 ◽  
Vol 292 (4) ◽  
pp. G1162-G1172 ◽  
Author(s):  
R. M. Gwynne ◽  
J. C. Bornstein

Mechanisms underlying nutrient-induced segmentation within the gut are not well understood. We have shown that decanoic acid and some amino acids induce neurally dependent segmentation in guinea pig small intestine in vitro. This study examined the neural mechanisms underlying segmentation in the circular muscle and whether the timing of segmentation contractions also depends on slow waves. Decanoic acid (1 mM) was infused into the lumen of guinea pig duodenum and jejunum. Video imaging was used to monitor intestinal diameter as a function of both longitudinal position and time. Circular muscle electrical activity was recorded by using suction electrodes. Recordings from sites of segmenting contractions showed they are always associated with excitatory junction potentials leading to action potentials. Recordings from sites oral and anal to segmenting contractions revealed inhibitory junction potentials that were time locked to those contractions. Slow waves were never observed underlying segmenting contractions. In paralyzed preparations, intracellular recording revealed that slow-wave frequency was highly consistent at 19.5 (SD 1.4) cycles per minute (c/min) in duodenum and 16.6 (SD 1.1) c/min in jejunum. By contrast, the frequencies of segmenting contractions varied widely (duodenum: 3.6–28.8 c/min, median 10.8 c/min; jejunum: 3.0–27.0 c/min, median 7.8 c/min) and sometimes exceeded slow-wave frequencies for that region. Thus nutrient-induced segmentation contractions in guinea pig small intestine do not depend on slow-wave activity. Rather they result from a neural circuit producing rhythmic localized activity in excitatory motor neurons, while simultaneously activating surrounding inhibitory motor neurons.


1983 ◽  
Vol 244 (1) ◽  
pp. G65-G70
Author(s):  
W. M. Yau ◽  
P. F. Lingle ◽  
M. L. Youther

This is a report on the effect of caerulein and methionine-enkephalin interaction on mechanical contraction and acetylcholine release in vitro. The ability of enkephalin to relax caerulein-induced contractions and the manner in which the caerulein dose-response curve was shifted in the presence of enkephalin strongly suggest that enkephalin and caerulein are functional antagonists in this system. The failure of enkephalin to alter the action of exogenous acetylcholine implies that such an antagonism is not mediated through a competition with postsynaptic muscarinic receptors on the muscle. Data from acetylcholine-release studies indicate that caerulein stimulation was dose related. As with the mechanical contractions, the release of acetylcholine in response to caerulein was inhibited by enkephalin. However, naloxone was capable of blocking this inhibition and restoring the release to its control level without interfering with caerulein stimulation. These data provide evidence for the modulatory roles of neuronal peptides in the cholinergic control of gut motility.


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