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Female pig urethral tone is dependent on Rho guanosine triphosphatases and Rho-associated kinase.

Malmqvist, Ulf LU ; Hedlund, Petter LU ; Swärd, Karl LU and Andersson, Karl-Erik LU (2004) In Journal of Urology 171(5). p.1955-1958
Abstract
PURPOSE: Circular smooth muscle of the urethra generates spontaneous myogenic tone of relevance for the maintenance of continence. We tested if Rho guanosine triphosphatases (GTPases) and Rho-associated kinase (ROK) are involved in the generation of urethral tone. MATERIALS AND METHODS: Small circular strips of female pig urethra were dissected out and mounted for recording isometric force. The effect of pharmacological agents known to modulate the activity of Rho GTPases or ROK was examined. The intracellular calcium concentration was measured using fura-2. RESULTS: Urethral tone was abolished by removing extracellular calcium or by adding the calcium antagonist felodipine. The decrease in force was closely related to a decrease in... (More)
PURPOSE: Circular smooth muscle of the urethra generates spontaneous myogenic tone of relevance for the maintenance of continence. We tested if Rho guanosine triphosphatases (GTPases) and Rho-associated kinase (ROK) are involved in the generation of urethral tone. MATERIALS AND METHODS: Small circular strips of female pig urethra were dissected out and mounted for recording isometric force. The effect of pharmacological agents known to modulate the activity of Rho GTPases or ROK was examined. The intracellular calcium concentration was measured using fura-2. RESULTS: Urethral tone was abolished by removing extracellular calcium or by adding the calcium antagonist felodipine. The decrease in force was closely related to a decrease in intracellular calcium concentration, indicating that tone depends on membrane associated mechanisms. Toxin B, which inactivates Rho GTPases, and Y 27632, which inhibits ROK, completely abolished tone in the female pig urethra. The latter effect occurred without any change in the intracellular calcium concentration. CONCLUSIONS: The results suggests that urethral tone depends on activity in G-protein coupled pathways and inhibition of this activity is sufficient for urethral tone relaxation. Thus, to our knowledge a new pathway in the generation of urethral tone, which might be acted on by autonomic nerves during micturition, has been identified. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
urethra, swine, muscle, smooth, rho-associated kinase, GTP-binding proteins
in
Journal of Urology
volume
171
issue
5
pages
1955 - 1958
publisher
Lippincott Williams & Wilkins
external identifiers
  • pmid:15076320
  • wos:000220872800055
  • scopus:13644254634
ISSN
1527-3792
DOI
10.1097/01.ju.0000121601.95857.5a
language
English
LU publication?
yes
id
04cc2cbc-3533-4826-9339-e86ab49f28c5 (old id 122765)
alternative location
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15076320&dopt=Abstract
date added to LUP
2007-07-17 12:50:19
date last changed
2017-01-01 06:49:50
@article{04cc2cbc-3533-4826-9339-e86ab49f28c5,
  abstract     = {PURPOSE: Circular smooth muscle of the urethra generates spontaneous myogenic tone of relevance for the maintenance of continence. We tested if Rho guanosine triphosphatases (GTPases) and Rho-associated kinase (ROK) are involved in the generation of urethral tone. MATERIALS AND METHODS: Small circular strips of female pig urethra were dissected out and mounted for recording isometric force. The effect of pharmacological agents known to modulate the activity of Rho GTPases or ROK was examined. The intracellular calcium concentration was measured using fura-2. RESULTS: Urethral tone was abolished by removing extracellular calcium or by adding the calcium antagonist felodipine. The decrease in force was closely related to a decrease in intracellular calcium concentration, indicating that tone depends on membrane associated mechanisms. Toxin B, which inactivates Rho GTPases, and Y 27632, which inhibits ROK, completely abolished tone in the female pig urethra. The latter effect occurred without any change in the intracellular calcium concentration. CONCLUSIONS: The results suggests that urethral tone depends on activity in G-protein coupled pathways and inhibition of this activity is sufficient for urethral tone relaxation. Thus, to our knowledge a new pathway in the generation of urethral tone, which might be acted on by autonomic nerves during micturition, has been identified.},
  author       = {Malmqvist, Ulf and Hedlund, Petter and Swärd, Karl and Andersson, Karl-Erik},
  issn         = {1527-3792},
  keyword      = {urethra,swine,muscle,smooth,rho-associated kinase,GTP-binding proteins},
  language     = {eng},
  number       = {5},
  pages        = {1955--1958},
  publisher    = {Lippincott Williams & Wilkins},
  series       = {Journal of Urology},
  title        = {Female pig urethral tone is dependent on Rho guanosine triphosphatases and Rho-associated kinase.},
  url          = {http://dx.doi.org/10.1097/01.ju.0000121601.95857.5a},
  volume       = {171},
  year         = {2004},
}