The effects of MK-801, an NMDA receptor antagonist, on the micturition reflex in the rat.
The effects of MK-801 (Dizocilpine) on the micturition reflex were studied in rats anesthetized with urethane (1.2 g/kg, s.c.). MK-801, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist (1-1000 micrograms/kg, i.v.) reduced, in a dose-dependent fashion the amplitude of rhythmic bladder contractions recorded isovolumetrically via a transurethral catheter. The largest doses (300-1000 micrograms/kg) completely abolished bladder activity. Bilateral section of the hypogastric nerves had no effect on MK-801 induced inhibition. MK-801 did not inhibit the bladder contractions induced by electrical stimulation of the pelvic nerve. These data suggest that MK-801 acts in the central nervous system to block glutaminergic excitatory transmission in the central micturition reflex pathway.
Yoshiyama
M
M
Department of Pharmacology, School of Medicine, University of Pittsburgh, PA 15261.
Roppolo
J R
JR
Rihmland
J
J
Blastos
B
B
de Groat
W C
WC
D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D009119:Muscle Contraction / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D012018:Reflex / Q000187:drug effects*; D014554:Urination / Q000187:drug effects*
D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate