In vitro effects of erythromycin, lidocaine, and metoclopramide on smooth muscle from the pyloric antrum, proximal portion of the duodenum, and middle portion of the jejunum of horses.
Abstract: To evaluate effects of erythromycin, lidocaine, and metoclopramide on smooth muscle of the pyloric antrum (PA), proximal portion of the duodenum (PD), and middle portion of the jejunum (MJ) of horses. Sample Population-Strips of smooth muscle from 7 horses. Methods: Isolated muscle strips were suspended in a bath and attached to isometric force transducers. Once stable spontaneous contractions were observed, agents were added. Isometric stress responses were compared with the amplitude of spontaneous contractions. Results: A single dose of erythromycin to the PA increased contractile amplitude (CA) for the longitudinal smooth muscle (mean +/- SEM, 76+/-16 g/cm2) but decreased CA for circular smooth muscle (-79+/-23 g/cm2). The inhibitory effect was decreased by tetrodotoxin, N(G)-nitro-L-arginine methyl ester, and a vasoactive intestinal peptide antagonist. Erythromycin increased CA for the MJ, which was maximal at 10(-4)M (171+/-36 g/cm2). Lidocaine increased CA for the PD, which was maximal at 10(-4) M (60+/-5 g/cm2). Metoclopramide increased the CA, which was maximal at 10(-4) M for the PA (75+/-26 g/cm2), PD (279+/-33 g/cm2), and MJ (456+/-59 g/cm2). Conclusions: Regional differences in responses to erythromycin, lidocaine, and metoclopramide were evident in the gastrointestinal tract of horses. Metoclopramide increased CA in all tissues used, whereas erythromycin inhibited CA in circular smooth muscle but stimulated CA in longitudinal smooth muscle from the PA. Inhibition is caused by stimulation of inhibitory nerves and is mediated, in part, by nitric oxide and vasoactive intestinal peptide.
Publication Date: 2000-04-20 PubMed ID: 10772106DOI: 10.2460/ajvr.2000.61.413Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research investigates the effects of three drugs (erythromycin, lidocaine, and metoclopramide) on the smooth muscle activity in three different sections of the horse’s digestive tract. The study discovered variant responses depending on the drug and the specific region of the gastrointestinal system, highlighting region-specific differences in horses’ digestive tract muscles.
Research Method
- The researchers gathered smooth muscle samples from the pyloric antrum (PA), proximal duodenum (PD), and middle jejunum (MJ) of seven horses.
- The muscle strips were isolated and placed in a bath connected to isometric force transducers, which measure the contractile strength of the muscle.
- Once consistent spontaneous contractions were established, the researchers introduced the respective drugs and observed the changes in isometric stress responses.
Key Findings
- Erythromycin increased the contractile amplitude (strength of muscle contraction) for the longitudinal smooth muscle in PA but decreased it for the circular smooth muscle. Notably, this inhibitory effect was decreased by tetrodotoxin, N(G)-nitro-L-arginine methyl ester, and a vasoactive intestinal peptide antagonist. This drug also increased contractile amplitude in the MJ.
- Lidocaine notably increased contractile amplitude for the PD.
- Metoclopramide increased contractile amplitude in all tested tissues – PA, PD, and MJ.
Conclusion
- The paper concludes that the gastrointestinal tract of horses shows regional differences in responses to erythromycin, lidocaine, and metoclopramide.
- Notably, erythromycin inhibits contractile amplitude in the circular smooth muscle but stimulates it in the longitudinal smooth muscle from the PA. The study identified that this inhibition stems from the stimulation of inhibitory nerves managed, partly, by nitric oxide and vasoactive intestinal peptides.
- Furthermore, metoclopramide was found to increase muscle contraction strength in all tested tissue types.
Cite This Article
APA
Nieto JE, Rakestraw PC, Snyder JR, Vatistas NJ.
(2000).
In vitro effects of erythromycin, lidocaine, and metoclopramide on smooth muscle from the pyloric antrum, proximal portion of the duodenum, and middle portion of the jejunum of horses.
Am J Vet Res, 61(4), 413-419.
https://doi.org/10.2460/ajvr.2000.61.413 Publication
Researcher Affiliations
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616, USA.
MeSH Terms
- Animals
- Anti-Arrhythmia Agents / administration & dosage
- Anti-Arrhythmia Agents / pharmacology
- Dopamine Antagonists / administration & dosage
- Dopamine Antagonists / pharmacology
- Duodenum / drug effects
- Erythromycin / administration & dosage
- Erythromycin / pharmacology
- Gastrointestinal Agents / administration & dosage
- Gastrointestinal Agents / pharmacology
- Horse Diseases / prevention & control
- Horses
- In Vitro Techniques
- Intestinal Obstruction / prevention & control
- Intestinal Obstruction / veterinary
- Jejunum / drug effects
- Lidocaine / administration & dosage
- Lidocaine / pharmacology
- Metoclopramide / administration & dosage
- Metoclopramide / pharmacology
- Muscle Contraction / drug effects
- Muscle, Smooth / drug effects
- Postoperative Complications / veterinary
- Pyloric Antrum / drug effects
Citations
This article has been cited 4 times.- Yau K, Halleran J, Boileau M, Foster D. Retrospective study on the use of lidocaine constant rate infusions for the treatment of ileus in ruminants and camelids.. J Vet Intern Med 2021 Nov;35(6):2933-2936.
- Röhm K, Diener M, Huber K, Seifert J. Characterization of Cecal Smooth Muscle Contraction in Laying Hens.. Vet Sci 2021 May 26;8(6).
- Salem SE, Proudman CJ, Archer DC. Has intravenous lidocaine improved the outcome in horses following surgical management of small intestinal lesions in a UK hospital population?. BMC Vet Res 2016 Jul 27;12(1):157.
- Koenig J, Cote N. Equine gastrointestinal motility--ileus and pharmacological modification.. Can Vet J 2006 Jun;47(6):551-9.
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