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Exogenously Administered Opioids Contract the Female Rat Intrinsic Urethral Sphincter In Vivo

Crayton, Robert; Soller, Wolfgang LU ; Mattiasson, Anders LU ; Bossowska, Agnieszka; Borkowski, Tomasz; Majewski, Mariusz and Radziszewski, Piotr (2010) In Neurourology and Urodynamics 29(5). p.777-782
Abstract
Background and objective: Previous studies have reported immunoreactive opioid nerve fibers in the detrusor and lower urinary tract sphincters. However, there is a paucity of in vivo studies demonstrating the direct effect of endogenous opioids in these structures. In the present study, we investigated the contractile actions of intra-arterially administered exogenous Dynorphin-A, Met-enkephalin, Leu-enkephalin, morphine, and the opioid antagonist naltrexone on the female rat intrinsic urethral sphincter in vivo. Methods: Intraurethral pressure was recorded by a catheter placed at the maximum pressure zone of the intrinsic urethral sphincter in anesthetized female Sprague-Dawley rats. The effects of different opioids were studied and... (More)
Background and objective: Previous studies have reported immunoreactive opioid nerve fibers in the detrusor and lower urinary tract sphincters. However, there is a paucity of in vivo studies demonstrating the direct effect of endogenous opioids in these structures. In the present study, we investigated the contractile actions of intra-arterially administered exogenous Dynorphin-A, Met-enkephalin, Leu-enkephalin, morphine, and the opioid antagonist naltrexone on the female rat intrinsic urethral sphincter in vivo. Methods: Intraurethral pressure was recorded by a catheter placed at the maximum pressure zone of the intrinsic urethral sphincter in anesthetized female Sprague-Dawley rats. The effects of different opioids were studied and expressed as means and as percentages of pressure change (cmH(2)O) of the baseline intraurethral pressure. Results: Dynorphin-A, Met-enkephalin, and Leu-enkephalin evoked rapid, long-lasting contractile effects on the female rat urethra. The greatest intraurethral pressure increase was evoked by Dynorphin-A (89.2 +/- 15.3%). For Met-enkephalin, intraurethral pressure increased by 70.2 +/- 21.8% and for Leu-enkephalin, the pressure increase was 60.6 +/- 20%. Morphine, however, evoked inconsistent intraurethral pressure changes, increasing the urethral pressure in three subjects and lowering the pressure in the remaining six subjects. The opioid antagonist naltrexone reduced the intraurethral pressure by a mean of -19.0 +/- 5.8%. Conclusion: Results of the present study suggest that endogenous opioids by their contractile action on the intrinsic urethral sphincter may play a role in the control of continence in rats, additional to cholinergic and noradrenergic pathways. Neurourol. Urodynam. 29:777-782, 2010. (C) 2010 Wiley-Liss, Inc. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
immunohistochemistry, intrinsic urethral sphincter, NANC, opioids
in
Neurourology and Urodynamics
volume
29
issue
5
pages
777 - 782
publisher
John Wiley & Sons
external identifiers
  • wos:000279299700014
  • scopus:77956814341
ISSN
0733-2467
DOI
10.1002/nau.20822
language
English
LU publication?
yes
id
214806a2-0061-4da5-8799-b5897356806b (old id 1628794)
date added to LUP
2010-07-21 16:55:38
date last changed
2018-05-29 10:07:13
@article{214806a2-0061-4da5-8799-b5897356806b,
  abstract     = {Background and objective: Previous studies have reported immunoreactive opioid nerve fibers in the detrusor and lower urinary tract sphincters. However, there is a paucity of in vivo studies demonstrating the direct effect of endogenous opioids in these structures. In the present study, we investigated the contractile actions of intra-arterially administered exogenous Dynorphin-A, Met-enkephalin, Leu-enkephalin, morphine, and the opioid antagonist naltrexone on the female rat intrinsic urethral sphincter in vivo. Methods: Intraurethral pressure was recorded by a catheter placed at the maximum pressure zone of the intrinsic urethral sphincter in anesthetized female Sprague-Dawley rats. The effects of different opioids were studied and expressed as means and as percentages of pressure change (cmH(2)O) of the baseline intraurethral pressure. Results: Dynorphin-A, Met-enkephalin, and Leu-enkephalin evoked rapid, long-lasting contractile effects on the female rat urethra. The greatest intraurethral pressure increase was evoked by Dynorphin-A (89.2 +/- 15.3%). For Met-enkephalin, intraurethral pressure increased by 70.2 +/- 21.8% and for Leu-enkephalin, the pressure increase was 60.6 +/- 20%. Morphine, however, evoked inconsistent intraurethral pressure changes, increasing the urethral pressure in three subjects and lowering the pressure in the remaining six subjects. The opioid antagonist naltrexone reduced the intraurethral pressure by a mean of -19.0 +/- 5.8%. Conclusion: Results of the present study suggest that endogenous opioids by their contractile action on the intrinsic urethral sphincter may play a role in the control of continence in rats, additional to cholinergic and noradrenergic pathways. Neurourol. Urodynam. 29:777-782, 2010. (C) 2010 Wiley-Liss, Inc.},
  author       = {Crayton, Robert and Soller, Wolfgang and Mattiasson, Anders and Bossowska, Agnieszka and Borkowski, Tomasz and Majewski, Mariusz and Radziszewski, Piotr},
  issn         = {0733-2467},
  keyword      = {immunohistochemistry,intrinsic urethral sphincter,NANC,opioids},
  language     = {eng},
  number       = {5},
  pages        = {777--782},
  publisher    = {John Wiley & Sons},
  series       = {Neurourology and Urodynamics},
  title        = {Exogenously Administered Opioids Contract the Female Rat Intrinsic Urethral Sphincter In Vivo},
  url          = {http://dx.doi.org/10.1002/nau.20822},
  volume       = {29},
  year         = {2010},
}