Non-NMDA glutamatergic excitatory transmission in the descending limb of the spinobulbospinal micturition reflex pathway of the rat.
I.v. administration of GYKI-52466, a non-competitive AMPA/kainate glutamatergic receptor antagonist, inhibited bladder contractions elicited by electrical stimulation in the pontine micturition center (PMC) in urethane-anesthetized rats. The mean threshold dose of GYKI-52466 was 2 mg/kg i.v. (range = 1-4 mg/kg). Maximum inhibition (mean = 57.7 +/- 8.2%, range = 24-83.3% of control) occurred at a dose of 8 mg/kg. CNQX, a competitive AMPA/kainate glutamatergic receptor antagonist, did not significantly alter the evoked contractions. These results indicate that AMPA/kainate receptors are involved in bulbospinal excitatory pathway from the PMC to the parasympathetic nucleus in the lumbosacral spinal cord in the rat.
Matsumoto
G
G
Department of Pharmacology, University of Pittsburgh, School of Medicine, PA 15261, USA.
Hisamitsu
T
T
de Groat
W C
WC
D000818:Animals; D014151:Anti-Anxiety Agents; D001569:Benzodiazepines / Q000494:pharmacology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D007275:Injections, Intravenous; D009434:Neural Pathways / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000166:cytology / Q000502:physiology; D011149:Pons / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000502:physiology*; D018092:Kainic Acid Receptors / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013116:Spinal Cord / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors; D001743:Urinary Bladder / Q000187:drug effects / Q000294:innervation; D014554:Urination / Q000502:physiology*
D014151:Anti-Anxiety Agents; D001569:Benzodiazepines; D016291:Dizocilpine Maleate; D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; C061950:GYKI 52466