GABAA and GABAB receptors modulate the K(+)-evoked release of sensory CGRP from the guinea pig urinary bladder

Life Sci. 1991;48(15):PL69-72. doi: 10.1016/0024-3205(91)90188-h.

Abstract

Superfusion of mucosa-free muscle slices of guinea-pig urinary bladder with 40 mM K+ produced a remarkable increase in calcitonin gene-related peptide-like immunoreactivity (CGRP-LI), that in this organ is entirely contained in capsaicin-sensitive nerves. GABA (1 mM) did neither affect the basal nor the 40 mM K+ evoked CGRP-LI release. Baclofen (0.1 mM) or muscimol (1 mM) did not affect the basal CGRP-LI outflow. However, baclofen (0.1 mM) significantly reduced by 32% and muscimol (0.1-1 mM) significantly increased by 60% and 70%, respectively the K(+)-evoked CGRP-LI release. These findings add neurochemical evidence to the functional data suggesting the existence of GABAA and GABAB receptors which modulate the efferent function of capsaicin-sensitive afferents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Baclofen / pharmacology
  • Calcitonin Gene-Related Peptide / metabolism*
  • Female
  • Guinea Pigs
  • In Vitro Techniques
  • Male
  • Muscimol / pharmacology
  • Potassium / physiology*
  • Receptors, GABA-A / classification
  • Receptors, GABA-A / drug effects
  • Receptors, GABA-A / physiology*
  • Urinary Bladder / physiology*

Substances

  • Receptors, GABA-A
  • Muscimol
  • Baclofen
  • Calcitonin Gene-Related Peptide
  • Potassium