Loss of caveolin-1 expression is associated with disruption of muscarinic cholinergic activities in the urinary bladder

H. Henry Lai, Timothy B. Boone, Guang Yang, Christopher P. Smith, Susanna Kiss, Timothy C. Thompson, George T. Somogyi

Research output: Contribution to journalArticle

45 Scopus citations

Abstract

Caveolin-1 (Cav1), a structural protein of caveolae, plays cell- and context-dependent roles in signal transduction pathway regulation. We have generated a knockout mouse homozygous for a null mutation of the Cav1 gene. Cav1 knockout mice exhibited impaired urinary bladder contractions in vivo during cystometry. Contractions of male bladder strips were evoked with electric and pharmacologic stimulation (5-40 Hz, 1-10 μM carbachol, 10 mM α,β-methylene ATP, 100 mM KCl). Acetylcholine (ACh) and norepinephrine (NE) release from bladder strips were measured with a radiochemical method by incubating the strips with 14C-choline and 3H-NE prior to electric stimulation, whereas ATP release was measured using the luciferin-luciferase assay with a luminometer. A 60-75% decline in contractility was observed when Cav1 knockout muscle strips were stimulated with electric current or carbachol, compared to wildtype muscle strips. No difference in contractility was noted when contractions were evoked either by the purinergic agonist α,β-methylene ATP, or by extracellular potassium. To investigate the relative contribution of non-cholinergic activity to bladder contractility, the amplitude of the electric stimulation-evoked contractions was compared in the presence of the muscarinic antagonist atropine (1 μM). While the non-muscarinic (purinergic) response was unaltered, muscarinic cholinergic response was principally disrupted in Cav1 knockout mice. The loss of Cav1 gene expression was also associated with a 70% reduction in ACh release. NE and ATP release was not altered. It is concluded that the loss of caveolin-1 is associated with disruption of M 3 muscarinic cholinergic activity in the bladder. Both pre-junctional (acetylcholine neurotransmitter release from neuromuscular junctions) and post-junctional (M 3 receptor-mediated signal transduction in bladder smooth muscles) mechanisms are disrupted, resulting in impaired bladder contraction.

Original languageEnglish
Pages (from-to)1185-1193
Number of pages9
JournalNeurochemistry International
Volume45
Issue number8
DOIs
StatePublished - Dec 1 2004
Externally publishedYes

Keywords

  • Acetylcholine
  • Caveolin-1
  • Noradrenaline

Fingerprint Dive into the research topics of 'Loss of caveolin-1 expression is associated with disruption of muscarinic cholinergic activities in the urinary bladder'. Together they form a unique fingerprint.

  • Cite this