Role of selective alpha and beta adrenergic receptor mechanisms in rat jejunal longitudinal muscle contractility

Seiler, Roland; Rickenbacher, Andreas; Shaw, Sidney; Haefliger, Simon; Balsiger, Bruno M (2008). Role of selective alpha and beta adrenergic receptor mechanisms in rat jejunal longitudinal muscle contractility. Journal of gastrointestinal surgery, 12(6), pp. 1087-93. New York, N.Y.: Springer-Verlag 10.1007/s11605-007-0327-4

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Gut motility is modulated by adrenergic mechanisms. The aim of our study was to examine mechanisms of selective adrenergic receptors in rat jejunum. Spontaneous contractile activity of longitudinal muscle strips from rat jejunum was measured in 5-ml tissue chambers. Dose-responses (six doses, 10(-7) -3 x 10(-5)M) to norepinephrine (NE, nonspecific), phenylephrine (PH, alpha1), clonidine (C, alpha2), prenalterol (PR, beta1), ritodrine (RI, beta2), and ZD7714 (ZD, beta3) were evaluated with and without tetrodotoxin (TTX, nerve blocker). NE(3 x 10(-5)M) inhibited 74 +/- 5% (mean +/- SEM) of spontaneous activity. This was the maximum effect. The same dose of RI(beta2), PH(alpha1), or ZD(beta(3)) resulted in an inhibition of only 56 +/- 5, 43 +/- 4, 33 +/- 6, respectively. The calculated concentration to induce 50% inhibition (EC50) of ZD(beta3) was similar to NE, whereas higher concentrations of PH(alpha1) or RI(beta2) were required. C(alpha2) and PR(beta1) had no effect. TTX changed exclusively the EC50 of RI from 4.4 +/- 0.2 to 2.7 +/- 0.8% (p < 0.04). Contractility was inhibited by NE (nonspecific). PH(alpha1), RI(beta2), and ZD(beta3) mimic the effect of NE. TTX reduced the inhibition by RI. Our results suggest that muscular alpha1, beta2, and beta3 receptor mechanisms mediate adrenergic inhibition of contractility in rat jejunum. beta2 mechanisms seem to involve also neural pathways.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > DCR Unit Tiefenau Hospital [discontinued] > Forschungsgruppe Vasoaktive Peptide [discontinued]

UniBE Contributor:

Shaw, Sidney

ISSN:

1091-255X

ISBN:

17879122

Publisher:

Springer-Verlag

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 15:06

Last Modified:

28 Oct 2019 20:20

Publisher DOI:

10.1007/s11605-007-0327-4

PubMed ID:

17879122

Web of Science ID:

000255629100015

BORIS DOI:

10.7892/boris.28558

URI:

https://boris.unibe.ch/id/eprint/28558 (FactScience: 121302)

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