Effects of the beta 3-adrenergic receptor agonist disodium 5-[(2R)-2-[[(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]-1,3-benzodioxole-2,2-dicarboxylate (CL-316243) on bladder micturition reflex in spontaneously hypertensive rats

J Pharmacol Exp Ther. 2008 Jul;326(1):178-85. doi: 10.1124/jpet.108.138651. Epub 2008 Apr 15.

Abstract

The present study investigated whether beta3-adrenoceptor activation acts on the bladder afferent pathway by examination of the visceromotor reflex (VMR) and pressor responses to urinary bladder distension (UBD) and whether beta3-adrenoceptor activation produces urinary bladder relaxation in hyperactive spontaneously hypertensive rats (SHRs) in comparison with their normotensive control rats [Wistar-Kyoto (WKY)]. Using the VMR responses to noxious UBD as a measure of bladder afferent signal transmission, SHRs did not present a sensitized bladder phenotype. However, reduced bladder compliance accompanied by a reduced void threshold was detected in the SHR detrusor. Furthermore, the selective beta3-adrenoceptor agonist disodium 5-[(2R)-2-[[(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]-1,3-benzodioxole-2,2-dicarboxylate (CL-316243) (i.v.) failed to attenuate VMR or pressor responses to UBD in either SHRs or WKY rats, but it dose-dependently inhibited rhythmic contraction (RC) in SHRs. The minimal effective dose was 0.001 mg/kg. Using the same model in WKY rats, CL-316243 did not elicit significant inhibition of contractions in the bladder RC assay. These results suggest that SHRs represent abnormal efferent/detrusor function (detrusor overactivity) without mechanosensory afferent hypersensitivity. The beta3-adrenoceptor agonist CL-316243 acts on the detrusor muscle to increase urine storage in SHRs.

Publication types

  • Comparative Study

MeSH terms

  • Adrenergic beta-3 Receptor Agonists*
  • Animals
  • Dioxoles / pharmacology*
  • Dioxoles / therapeutic use
  • Female
  • Muscle Contraction / drug effects
  • Muscle Contraction / physiology
  • Rats
  • Rats, Inbred SHR
  • Rats, Inbred WKY
  • Receptors, Adrenergic, beta-3 / physiology
  • Urinary Bladder / drug effects*
  • Urinary Bladder / physiology
  • Urinary Bladder, Overactive / drug therapy
  • Urinary Bladder, Overactive / physiopathology
  • Urination / drug effects*
  • Urination / physiology

Substances

  • Adrenergic beta-3 Receptor Agonists
  • Dioxoles
  • Receptors, Adrenergic, beta-3
  • disodium (R,R)-5-(2-((2-(3-chlorophenyl)-2-hydroxyethyl)-amino)propyl)-1,3-benzodioxole-2,3-dicarboxylate