Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1999-7-30
pubmed:abstractText
The external urethral sphincteric mechanism generates forces which seal the urethra and can be measured as urethral pressure. Resting pressure can be augmented transiently through a reflex pathway during increases in intra-abdominal pressure. The exact role of the various components of the urethral wall that generate this pressure is so far unknown. Urethral contributions to continence come from the mucosal hermetic seal, the submucosa and its vascular filling and the smooth and striated muscle. In humans alpha1-adrenoceptor antagonists can reduce urethral pressure, whereas agonists have little effect. A significant part of urethral resting tone is thought to be mediated through the smooth muscles. In vitro, longitudinal and circular smooth muscle components possess spontaneous tone and are innervated by excitatory and inhibitory nerves. Both types possess alpha1-adrenoceptors and contract on stimulation of intrinsic sympathetic nerves or application of alpha1-adrenoceptor agonists. In human urethra, longitudinal smooth muscle predominates but its functional role is unclear. alpha1 stimulation may also affect the vasculature of the submucosa, the striated muscle of the urethra or transmitter release from neurones in the control pathways. Insufficient knowledge of alpha1-adrenoceptor distribution and function within the urethra and the surrounding tissues currently prevents accurate prediction of the therapeutic potential of alpha1-adrenoceptor ligands.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0302-2838
pubmed:author
pubmed:issnType
Print
pubmed:volume
36 Suppl 1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
74-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
alpha1-adrenoceptors in urethral function.
pubmed:affiliation
University Department of Pharmacology, Oxford (UK).
pubmed:publicationType
Journal Article, In Vitro