Inhibitory effect of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) on the micturition reflex in rat.
The effect of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), an alpha-amino-hydroxy-5-methyl-4-isoxazole propionate (AMPA) glutamate receptor antagonist, on bladder contractions was examined under isometric conditions in urethane anesthetized rats. Intravenous administration of CNQX (33 ng-50 micrograms/kg) inhibited or abolished bladder contraction. Before complete inhibition, the frequency of bladder contractions was reduced without altering the amplitude or duration. Intrathecal administration of CNQX (2 ng/kg-11 micrograms/kg) similarly inhibited bladder contractions. In contrast, CNQX did not affect bladder contractions in chronically spinalized animals (6.7 ng/kg-400 micrograms/kg i.v.), or contractions evoked by stimulation of the decentralized pelvic nerve (1-100 micrograms/kg i.v.).
Department of Physiology, School of Medicine, Showa University, Tokyo, Japan.
G
G
Matsumoto
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M
Kawatani
C
C
Takeshige
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000818:Animals; D005260:Female; D007278:Injections, Spinal; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D011810:Quinoxalines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D018091:Receptors, AMPA; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors / Q000502:physiology; D012018:Reflex / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D001743:Urinary Bladder / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D014554:Urination / Q000187:drug effects*
D011810:Quinoxalines; D018091:Receptors, AMPA; D017981:Receptors, Neurotransmitter; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione