Neural control of canine colon motor function: studies in vitro

1988 ◽  
Vol 66 (3) ◽  
pp. 359-368 ◽  
Author(s):  
T. Gonda ◽  
E. E. Daniel ◽  
F. Kostolanska ◽  
M. Oki ◽  
J. E. T. Fox
Keyword(s):  
Substance P ◽  
Neural Control ◽  
Circular Muscle ◽  
Distal Colon ◽  
Field Stimulation ◽  
Inhibitory Effects ◽  
Release Of Acetylcholine ◽  
Neural Excitation

The responses of strips of the canine colon to stimulation of intrinsic nerves and to the probable mediators of these nerves were studied in vitro. Studies were carried out using longitudinal and circular muscle strips from proximal and distal colon with field stimulation and addition of agents to the bath. Overall, these and other studies in vivo suggested that acetylcholine was an ubiquitous mediator of neural excitation. Norepinephrine had mixed inhibitory and excitatory effects, the latter only in circular muscle. Inhibitory effects of norepinephrine seemed to be both pre- and post-synaptic but no evidence that it was released by field stimulation was obtained. Substance P had excitatory effects chiefly by release of acetylcholine. It, in addition to norepinephrine, at least in circular muscle, deserves evaluation as the mediator of noncholinergic excitation to high frequency field stimulation. Although vasoactive intestinal peptide sometimes had inhibitory effects, these were incomplete and inconsistent. However, further evaluation of its possible role as a nonadrenergic, noncholinergic inhibitory mediator is required to determine if it is involved as one component in the response. Few qualitative differences existed between responses of various regions of the colon to potential neuromediators, although there were some consistent differences between responses of longitudinal and circular muscle. Some differences existed in responses obtained earlier in vivo and in vitro. In particular, inhibitory effects following excitation by substance P on field stimulation were found only in vivo. Nonadrenergic, noncholinergic inhibitory responses to field stimulation were consistently present only in vitro. These differences have not been explained.

Multiple responses to electrical field stimulation in circular muscle of canine gastric corpus

1984 ◽  
Vol 62 (8) ◽  
pp. 912-918 ◽  
Author(s):  
Yasushi Sakai ◽  
Edwin E. Daniel
Keyword(s):  
Substance P ◽  
Circular Muscle ◽  
Electrical Field Stimulation ◽  
Scorpion Venom ◽  
Adrenergic Blockade ◽  
Field Stimulation ◽  
Electrical Field ◽  
Gastric Corpus

Innervation of circular muscle of the canine stomach studied in vitro was investigated by subjecting muscle strips to electrical field stimulation. Strips were cut from the lesser curvature of the gastric corpus and stimulated with 10-s trains of 0.5-ms pulses at 0.5–20 Hz, 40 V. Most responses were classified into one of three types. In general, field stimulation tended to elicit sequences of varying magnitudes of transient on-contraction, on-relaxation, off-relaxation, off-contraction. Responses were abolished by tetrodotoxin. On-contraction was almost abolished by atropine plus desensitization by 5-hydroxytryptamine (5-HT) or substance P. On-relaxation and off-relaxation were not affected by adrenergic blockade, methysergide, apamin, or 4-aminopyridine. ATP usually caused contraction and slightly diminished relaxation to field stimulation. Vasoactive intestinal polypeptide (VIP) had little effect on tone and response to field stimulation. Relaxation disappeared after scorpion venom treatment. This probably resulted from depletion of the transmitter which mediates relaxation. Off-contraction was reduced by atropine, desensitization by 5-HT or substance P, cromoglycate, indomethacin or ATP, but was not affected by adrenergic blockade, hexamethonium, methysergide, mepyramine, or VIP. The findings suggest that innervation of gastric corpus circular muscle included excitatory cholinergic and both excitatory and inhibitory noncholinergic, nonadrenergic innervation. However, the responses of circular muscle to field stimulation in vitro were drastically different from those obtained previously in vivo, suggesting damage or altered inputs to circular muscle when strips of circular muscle are studied.

Substance P: a potent inhibitor of the canine small intestine in vivo

1986 ◽  
Vol 250 (1) ◽  
pp. G21-G27 ◽  
Author(s):  
J. E. Fox ◽  
E. E. Daniel
Keyword(s):  
Small Intestine ◽  
Substance P ◽  
Circular Muscle ◽  
Opiate Receptor ◽  
Inhibitory Effect ◽  
Inhibitory Response ◽  
Substance P Antagonist ◽  
Release Of Acetylcholine

Intra-arterially administered substance P inhibited neurally activated contractions of the circular muscle of canine small intestine in vivo (lowest effective dose approximately 10(-13) mol). Excitation of intestine required higher (10(-10) mol) doses. The inhibitory effect required functioning nerves, since tetrodotoxin treatment eliminated it. However, inhibition of neurogenic contraction by substance P was unaffected by nicotinic or opiate receptor antagonists or by catecholamine depletion but was reduced by a selective substance P antagonist. Since the inhibition by substance P was also greatly reduced by treatment with atropine or pirenzepine and acetylcholine given intra-arterially produced a similar inhibitory response, stimulation of release of acetylcholine to inhibitory muscarinic receptors on nerves appeared to be the mechanism of this action. Direct smooth muscle effects were ruled out; substance P did not inhibit contractions to intra-arterial acetylcholine or those following tetrodotoxin. In vitro in ileal strips, no inhibition by substance P of any contractile response was found. We propose that the local release of substance P into the myenteric plexus produces inhibition and suggest that this constitutes a physiological function of the neuropeptide. This action may be absent in vitro.

Studies in vivo and in vitro on effects of PGE2 on colonic motility in rabbits

1992 ◽  
Vol 262 (1) ◽  
pp. G23-G29 ◽  
Author(s):  
R. Burakoff ◽  
W. H. Percy
Keyword(s):  
Colonic Motility ◽  
Circular Muscle ◽  
Distal Colon ◽  
Muscle Layer ◽  
Distal Region ◽  
Mechanical Activity ◽  
Experimental Conditions ◽  
Motor Effects

Prostaglandins (PG) of the E series are synthesized throughout the gastrointestinal tract, and their elevated levels have been reported in many diarrheal states, including inflammatory bowel disease. It is already known that PGE2 has region-specific and muscle layer-specific effects in different areas of the intestine. The aim of this study was to evaluate possible dose-related motor effects of PGE2 on rabbit proximal and distal colon both in vivo and in vitro. We found that, in the proximal colon in vivo, PGE2 caused inhibition of myoelectric and mechanical activity at low doses but at higher doses caused marked excitation. Under the same experimental conditions, PGE2 caused only excitation in the distal colon, a phenomenon associated with an increase in antegrade contractions and diarrhea. In vitro, PGE2 caused excitation of both proximal and distal colonic longitudinal muscle and relaxation of the circular muscle. Its actions, however, were much more pronounced in the distal region. It is concluded that PGE2 has profound effects on colonic motility that are concentration dependent and that differ with the region of the colon under study. Furthermore, the evidence also suggests that elevated PGE2 levels in disease states may play a significant role in abnormal colonic motility and may facilitate the onset of diarrhea.

Neural control of canine colon motor function: studies in vivo

1988 ◽  
Vol 66 (3) ◽  
pp. 350-358 ◽  
Author(s):  
T. Gonda ◽  
E. E. Daniel ◽  
F. Kostolanska ◽  
M. Oki ◽  
J. E. T. Fox
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
High Frequency ◽  
Neural Control ◽  
Circular Muscle ◽  
In Vivo Studies ◽  
Field Stimulation ◽  
High Frequency Field ◽  
Frequency Field ◽  
Stimulation Of

The responses of the circular muscle of canine colon to stimulation of intrinsic nerves and to the probable mediators of these nerves were studied in vivo. In vivo studies were carried out using close intra-arterial injections and local field stimulation of proximal, mid-, and distal colon while recording circumferential contractions. Our results suggest that acetylcholine is the major excitatory mediator, but another excitatory mediator could be released by high frequency field stimulation after atropine. Norepinephrine had mixed inhibitory and excitatory effects, but no evidence was obtained that it was released by field stimulation. Substance P had mainly excitatory effects partly by a mechanism involving nerves and partly by a direct effect on muscle; it in addition to norepinephrine deserves further evaluation as the mediator of noncholinergic excitation to high frequency field stimulation. There is no explanation of the inhibition it produced after initial excitation during field stimulation. Vasoactive intestinal peptide had inhibitory effects but these were incomplete and inconsistent. This may be related to our inability to demonstrate relaxation or inhibition to field stimulation after atropine. Further evaluation of the possible role of vasoactive intestinal peptide and other agents as nonadrenergic, noncholinergic inhibitory mediators is required.

Leukotriene D4 excitation of rabbit distal colon arises in the region of the muscularis mucosae

1990 ◽  
Vol 259 (5) ◽  
pp. G753-G759
Author(s):  
W. H. Percy ◽  
S. Y. Lee ◽  
M. B. Burton ◽  
T. Tolentino ◽  
R. Burakoff
Keyword(s):  
Muscularis Propria ◽  
Circular Muscle ◽  
Distal Colon ◽  
Muscle Layer ◽  
Mechanical Activity ◽  
Muscularis Mucosae ◽  
Leukotriene D4 ◽  
In Vitro Techniques

We previously have demonstrated in vivo that intra-arterial administration of leukotriene D4 (LTD4) causes increased myoelectric and mechanical activity in the rabbit distal colon. The aim of this study was to use both in vivo and in vitro techniques to try to elucidate the mechanism underlying this effect. In vivo the excitatory response of the rabbit distal colon to LTD4 was abolished by pretreatment with atropine (0.1 mg/kg iv) or hexamethonium (5 mg/kg iv) or the LTD4 receptor antagonist SK&F 102922 (0.8 micrograms/kg ia). In vitro neither the longitudinal nor the circular muscle layer responded to LTD4 (10(-10) to 10(-7) M) with a contractile response. Over the same concentration range, LTD4 caused contractions of the muscularis mucosae that were attenuated by either SK&F 102922 (10(-9) to 10(-7) M) or indomethacin (10(-6) M) but were unaffected by atropine (10(-6) M), pyrilamine (10(-6) M), or tetrodotoxin (10(-6) M). Full thickness segments of longitudinal muscle, circular muscle, and muscularis mucosae did not contract to LTD4. These data imply that LTD4-induced excitation of the rabbit distal colon in vivo arises as a result of the excitation of LTD4 receptors in the region of the muscularis mucosae and that this leads ultimately to the release of acetylcholine onto the muscularis propria. It is proposed that one possible mechanism leading to the latter effect is an increased excitability of intrinsic nerves resulting from a prostaglandin-induced depression of norepinephrine release from nerves impinging on the submucosal plexus.

Cholinergic and nitrergic regulation of in vivo giant migrating contractions in rat colon

2002 ◽  
Vol 283 (3) ◽  
pp. G544-G552 ◽  
Author(s):  
Mona Li ◽  
Christopher P. Johnson ◽  
Mark B. Adams ◽  
Sushil K. Sarna
Keyword(s):  
Circular Muscle ◽  
Distal Colon ◽  
Rat Colon ◽  
Receptor Subtype ◽  
Colonic Motor ◽  
Calcitonin Gene ◽  
Colonic Motor Activity ◽  
Release Of Acetylcholine ◽  
Giant Migrating Contractions

The aim of this study was to characterize in vivo rat colonic motor activity in normal and inflamed states and determine its neural regulation. Circular muscle contractions were recorded by surgically implanted strain-gauge transducers. The rat colon exhibited predominantly giant migrating contractions (GMCs) whose frequency decreased distally. Only a small percentage of these GMCs propagated in the distal direction; the rest occurred randomly. Phasic contractions were present, but their amplitude was very small compared with that of GMCs. Inflammation induced by oral administration of dextran sodium sulfate suppressed the frequency of GMCs in the proximal and middle but not in the distal colon. Frequency of GMCs was suppressed by intraperitoneally administered atropine and 4-diphenylacetoxy- N-methyl-piperidine methiodide and was enhanced by N w-nitro-l-arginine methyl ester. Serotonin, tachykinin, and calcitonin gene-related peptide receptor or receptor subtype antagonists as well as guanethidine and suramin had no significant effect on the frequency of GMCs. Verapamil transiently suppressed the GMCs. In conclusion, unlike the canine and human colons, the rat colon exhibits frequent GMCs and their frequency is suppressed in inflammation. In vivo GMCs are stimulated by neural release of acetylcholine that acts on M3 receptors. Constitutive release of nitric oxide may partially suppress their frequency.

Structural basis for function of circular muscle of canine corpus

1984 ◽  
Vol 62 (10) ◽  
pp. 1304-1314 ◽  
Author(s):  
E. E. Daniel ◽  
Y. Sakai ◽  
J. E. T. Fox ◽  
V. Posey-Daniel
Keyword(s):  
Smooth Muscle ◽  
Gap Junctions ◽  
Neural Control ◽  
Circular Muscle ◽  
Muscle Cells ◽  
Structural Basis ◽  
Tight Coupling ◽  
Granular Vesicles

The structural relationship of nerve, muscle, and interstitial ceils of Cajal in circular muscle of the lesser curvature of the dog stomach (corpus) has been studied. This muscle has also been characterized functionally. Muscle cells are arranged in bundles and are interconnected by numerous gap junctions averaging 30 per 100 cross-sectioned muscle cells, and leading to an estimate that each cell has about 200 gap junctions. No other smooth muscle studied to date has such a high density of gap junctions. Nerve varicosities, mostly containing a predominance of small agranular vesicles with some containing a predominance of large granular vesicles, are located outside muscle bundles, usually in small- to medium-sized bundles. Very few nerves containing small granular vesicles, presumably adrenergic, were found in agreement with functional studies. A substantial number of damaged nerve profiles was also found, perhaps contributing to the loss of nerve-dependent responses present in vivo, but absent in vitro. Interstitial cells of Cajal were rare in this tissue, about 1 per 1000 cross-sectioned muscle cells. When present, they often made gap junction contact with smooth muscle and were closely innervated. The findings of a structural basis for very tight coupling between cells, the absence of a structural basis for direct neural control over motor function, and other findings have implications for the control of contractions in this muscle.

Inhibitory effects of epimedium herb water extract on the inflammatory response in vitro and in vivo

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
YC Oh ◽  
YH Jeong ◽  
WK Cho ◽  
SJ Lee ◽  
JY Ma
Keyword(s):  
Inflammatory Response ◽  
Water Extract ◽  
Inhibitory Effects

The Effects of Brinolase (Fibrinolytic Enzyme from Aspergillus Oryzae) on Platelet Aggregation of Dog and Man

1972 ◽  
Vol 28 (01) ◽  
pp. 031-048 ◽  
Author(s):  
W. H. E Roschlau ◽  
R Gage
Keyword(s):  
Platelet Aggregation ◽  
Aspergillus Oryzae ◽  
Degradation Products ◽  
Blood Platelet ◽  
Human Platelets ◽  
Fibrinolytic Enzyme ◽  
Inhibitory Effects ◽  
Blood Platelet Aggregation

SummaryInhibition of blood platelet aggregation by brinolase (fibrinolytic enzyme from Aspergillus oryzae) has been demonstrated with human platelets in vitro and with dog platelets in vivo and in vitro, using both ADP and collagen as aggregating stimuli. It is suggested that the optimal inhibitory effects of brinolase occur indirectly through the generation of plasma fibrinogen degradation products, without compromising platelet viability, rather than by direct proteolysis of platelet structures.

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