Interleukin-1 beta modulation of norepinephrine release from rat myenteric nerves

1993 ◽  
Vol 264 (1) ◽  
pp. G30-G35 ◽  
Author(s):  
S. Hurst ◽  
S. M. Collins
Keyword(s):  
Myenteric Plexus ◽  
Longitudinal Muscle ◽  
Interleukin 1 ◽  
Electrical Field Stimulation ◽  
Time Dependent ◽  
Interleukin 1 Beta ◽  
Norepinephrine Release ◽  
Rat Intestine ◽  
Electrical Field ◽  
Methionine Uptake

We examined the ability of human recombinant interleukin-1 beta (hrIL-1 beta) to alter the release of [3H]norepinephrine ([3H]NE) by KCl or electrical field stimulation in longitudinal muscle-myenteric plexus of rat intestine. The cytokine had no immediate effect on either the basal or evoked release of [3H]NE. However, hrIL-1 beta caused a biphasic time-dependent suppression of evoked [3H]NE release that was delayed in onset. IL-1 beta also stimulated the cycloheximide-sensitive uptake of [35S] methionine uptake by the tissue. The initial suppression of [3H]NE release was observed after 30 min and could not be inhibited by cycloheximide. A delayed peak was observed after 120 min and was inhibited by cycloheximide. The effect of IL-1 beta was maximal at 10 ng/ml and could be prevented by a neutralizing anti-IL-1 beta antibody or by preincubating the tissue with an IL-1-receptor antagonist. These results indicate that IL-1 beta suppresses [3H]NE release from rat myenteric plexus by two mechanisms, one of which is independent of protein synthesis and the other of which is mediated by endogenous IL-1.

Impaired acetylcholine release from the myenteric plexus of Trichinella-infected rats

1989 ◽  
Vol 257 (6) ◽  
pp. G898-G903 ◽  
Author(s):  
S. M. Collins ◽  
P. A. Blennerhassett ◽  
M. G. Blennerhassett ◽  
D. L. Vermillion
Keyword(s):  
Myenteric Plexus ◽  
Acetylcholine Release ◽  
Longitudinal Muscle ◽  
Trichinella Spiralis ◽  
Electrical Field Stimulation ◽  
Field Stimulation ◽  
Ach Release ◽  
Electrical Field ◽  
Release Of Acetylcholine

We examined the release of acetylcholine (ACh) from jejunal longitudinal muscle-myenteric plexus preparations in noninfected control rats and in rats infected 6, 23, or 40 days previously with Trichinella spiralis. ACh release was assessed by preincubating the tissue with [3H]choline and measuring the evoked release of tritium. The uptake of 3H was significantly less in tissue from T. spiralis-infected rats compared with control. In tissues from either infected or control animals, electrical field stimulation (30 V, 0.5 ms, 10 Hz for 1 min), or veratridine (6-30 microM) induced 3H release that was tetrodotoxin sensitive. Depolarization by KCl (25-75 mM) also caused 3H release, but this was only partially reduced by tetrodotoxin. Radiochromatographic analysis indicated evoked release of 3H to be almost entirely [3H]ACh. In rats infected 6 days previously with T. spiralis, [3H]ACh release induced by KCl, veratridine, and field stimulation were decreased at least 80%. The suppression of [3H]ACh release induced by veratridine or KCl was fully reversible after 40 days postinfection, but field-stimulated responses remained approximately 50% of control values. These results indicate that T. spiralis infection in the rat is accompanied by a reversible suppression of ACh release from the longitudinal muscle-myenteric plexus of the jejunum.

P1 Aspartate-Based Peptide .alpha.-((2,6-Dichlorobenzoyl)oxy)methyl Ketones as Potent Time-Dependent Inhibitors of Interleukin-1.beta.-Converting Enzyme

1994 ◽  
Vol 37 (5) ◽  
pp. 563-564 ◽  
Author(s):  
Roland E. Dolle ◽  
Denton Hoyer ◽  
C. V. C. Prasad ◽  
Stanley J. Schmidt ◽  
Carla T. Helaszek ◽  
...  
Keyword(s):  
Interleukin 1 ◽  
Time Dependent ◽  
Interleukin 1 Beta ◽  
Converting Enzyme ◽  
Methyl Ketones

Serotonin reuptake inhibitors fluoxetine and citalopram relax intestinal smooth muscle

2001 ◽  
Vol 79 (7) ◽  
pp. 580-584 ◽  
Author(s):  
Pal Pacher ◽  
Zoltan Ungvari ◽  
Valéria Kecskeméti ◽  
Tamás Friedmann ◽  
Susanna Furst
Keyword(s):  
Smooth Muscle ◽  
Serotonin Reuptake ◽  
Longitudinal Muscle ◽  
Contractile Activity ◽  
Electrical Field Stimulation ◽  
Intestinal Smooth Muscle ◽  
Dependent Manner ◽  
Guinea Pig Ileum ◽  
Electrical Field ◽  
Concentration Dependent Manner

Selective serotonin reuptake inhibitor antidepressants (SSRIs) exert depressant effects on cardiac myocytes and vascular smooth muscle cells by inhibiting Ca2+ channels. We hypothesized that the SSRIs fluoxetine and citalopram affect the contractile activity of intestinal smooth muscle by interfering with Ca2+ entry and (or) signaling pathways. The effects of fluoxetine and citalopram on contractions of guinea-pig ileum longitudinal muscle-myenteric plexus preparations (LMMP) were compared with the effects of the voltage-operated Ca2+ channel inhibitors nifedipine and diltiazem. In a concentration-dependent manner, nifedipine, diltiazem, fluoxetine, and citalopram elicited relaxation of LMMPs contracted by electrical field stimulation (EC50 values of 4 × 10–7 M, 1.4 × 10–6 M, 1.4 × 10–5, and 6.8 × 10–6 M, respectively). Nifedipine, diltiazem, fluoxetine, and citalopram also relaxed LMMPs contracted with a depolarizing concentration of KCl (48 mM; EC50 values of 1.8 × 10–8 M, 1.4 × 10–7 M, 3.7 × 10–6 M, and 6.3 × 10–6, respectively), a response that could be reversed by increasing the extracellular Ca2+ concentration (2.5–30 mM). These data suggest that fluoxetine and citalopram elicit relaxation of intestinal smooth muscle, likely by inhibiting Ca2+ channel(s). This effect may be of clinical importance.Key words: fluoxetine (Prozac(r)), citalopram (Seropram(r)), nifedipine, diltiazem, L-type Ca2+ channels, intestinal smooth muscle.

Impaired acetylcholine release in the inflamed rat intestine is T cell independent

1992 ◽  
Vol 263 (2) ◽  
pp. G198-G201 ◽  
Author(s):  
S. M. Collins ◽  
P. Blennerhassett ◽  
D. L. Vermillion ◽  
K. Davis ◽  
J. Langer ◽  
...  
Keyword(s):  
T Cell ◽  
T Lymphocytes ◽  
Inflammatory Response ◽  
Myenteric Plexus ◽  
Acetylcholine Release ◽  
Longitudinal Muscle ◽  
Trichinella Spiralis ◽  
Ach Release ◽  
Rat Intestine ◽  
Marked Suppression

We investigated mechanisms underlying the suppression of [3H]acetylcholine ([3H]ACh) release from myenteric plexus-longitudinal muscle preparations of rats infected 6 days previously with Trichinella spiralis. There was a 73% suppression of KCl-evoked release of [3H]ACh in the jejunum, and a 76% suppression was observed in the worm-free ileum, indicating that the local presence of the parasite in the lumen is not prerequisite for the suppression of ACh release from the myenteric plexus. Treatment of rats with betamethasone (3 mg.kg-1.day-1 ip) during the infection prevented the acute inflammatory response and attenuated the suppression of [3H]-ACh release (from 73 to 22%) in the jejunum of infected rats. This finding is consistent with the hypothesis that the suppression of ACh release occurs as a result of the inflammatory process. Marked suppression of [3H]ACh release was also seen in T. spiralis-infected nude athymic rats, which were shown to lack functioning T lymphocytes. Thus changes in ACh release are not dependent on T lymphocytes. Taken in conjunction with our previously published study showing that altered muscle function in this model is T cell dependent, the results of the present study indicate that different components of the inflammatory response mediate changes in smooth muscle and myenteric nerves in the T.spiralis infected rat.

A comparison of intrinsic nerve supplies of two muscular layers of duodenum.

1977 ◽  
Vol 233 (1) ◽  
pp. E28
Author(s):  
S Anuras ◽  
J Christensen ◽  
A R Cooke
Keyword(s):  
Longitudinal Muscle ◽  
Gastrointestinal Hormones ◽  
Circular Muscle ◽  
Electrical Field Stimulation ◽  
Cholinergic Innervation ◽  
Muscle Strip ◽  
Field Stimulation ◽  
Cholinergic Transmission ◽  
Electrical Field ◽  
Intrinsic Nerve

The duodenums of opossums and cats were cut into strips 2 mm wide and 2-2.5 cm long. Strips cut in the direction of the oral-caudal axis were called longitudinal strips, and those cut at 90 degrees to that axis were called circular strips. Each muscle strip was stimulated with trains of electrical rectangular pulses (10 Hz, 50-70 V, 0.5 ms). In the longitudinal strips, electrical field stimulation caused contraction, and this contraction was abolished by atropine, 10(-7) M. In the circular strips, electrical field stimulation caused relaxation. This relaxation was abolished by tetrodotoxin, 10(-7) M, but it was not affected by antagonists to adrenergic and cholinergic transmission, nor by some gastrointestinal hormones. Reserpinization of the opossums or alteration of the frequencies of electrical field stimulation from 0.1-50 Hz did not affect or alter the relaxation of the circular strips or the contraction of the longitudinal strips. These findings suggest that the longitudinal muscle is dominated by an excitatory cholinergic innervation, and the circular muscle is dominated by a nonadrenergic, noncholinergic inhibitory innervation.

Endothelin A-receptor blockade in experimental diabetes improves glucose balance and gastrointestinal function

2002 ◽  
Vol 103 (s2002) ◽  
pp. 430S-433S ◽  
Author(s):  
Bruno BALSIGER ◽  
Andreas RICKENBACHER ◽  
Penelope Jane BODEN ◽  
Erwin BIECKER ◽  
Janice TSUI ◽  
...  
Keyword(s):  
Type Ii Diabetes ◽  
Longitudinal Muscle ◽  
Electrical Field Stimulation ◽  
Receptor Blockade ◽  
Field Stimulation ◽  
Type Ii ◽  
Secondary Complications ◽  
Electrical Field ◽  
Glucose Clearance ◽  
Eta Receptor

Secondary complications of diabetes mellitus often involve gastrointestinal dysfunction. In the experimental Goto Kakizaki rat, a model of Type II diabetes, hyperglycaemia and reduced glucose clearance is associated with elevated plasma endothelin (ET)-1 levels and selective decreases in nitric oxide synthase in circular muscle, longitudinal muscle and neuronal elements of the gastrointestinal tract. Functionally, this is accompanied by decreased nitrergic relaxatory responses of jejunal longitudinal muscle to tetrodotoxin-sensitive electrical field stimulation. Long-term treatment with a selective ET A-type receptor antagonist, markedly reduced hyperglycaemia and restored plasma glucose clearance rates towards normal. This was associated with a restoration of NG-nitro-L-arginine methyl ester-sensitive relaxatory responses of jejunal longitudinal muscle to electrical field stimulation. The results indicate that beneficial effects of ETA receptor blockade on gastrointestinal function may result from an improvement in insulin sensitivity with concomitant reduction of the severity of hyperglycaemia. ETA receptor blockade may represent a new therapeutic principle for improving glucose tolerance in Type II diabetes and could be beneficial in alleviating or preventing hyperglycaemia-related secondary complications in this condition.

An ultrastructural analysis of the sympathetic innervation of the rabbit ear artery and middle cerebral artery and their branches

1992 ◽  
Vol 50 (1) ◽  
pp. 934-935
Author(s):  
John T. Dodge ◽  
John A. Bevan
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Sympathetic Innervation ◽  
Electrical Field Stimulation ◽  
Rabbit Ear Artery ◽  
Electrical Field ◽  
Functional Differences ◽  
Ear Artery ◽  
Rabbit Ear ◽  
Vascular Beds

Unlike many peripheral vascular beds, the sympathetic nervous system exerts little control on cerebral blood flow. The contractile response of isolated rabbit middle cerebral artery (MCA) segments to electrical field stimulation of its intramural nerves is less than in a similar-sized artery from the ear. This study was undertaken to characterize and compare the perivascular neuromuscular relationships and innervation density of similar-sized arteries varying in diameter from these two different regional arterial beds to see if there were structural correlates for these functional differences.

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