The effect of MK-801 on the micturition reflex in anesthetized rats.
We studied the effect of MK-801, a potent non-competitive NMDA receptor antagonist, on the micturition reflex in anesthetized rats. Pretreatment with MK-801 (0.1-1 mg/kg i.v.) dose dependently increased the bladder capacity and reduced the micturition contraction. The ability of MK-801 to inhibit bladder voiding was confirmed in additional experiments in which the compound (30-50 micrograms/kg i.v.) transiently suppressed established bladder voiding produced by continuous bladder filling. MK-801 (1 microM) did not affect nerve-mediated contractions of the rat bladder or inhibit the response to capsaicin. These findings provide pharmacological evidence for an involvement of NMDA receptors in the micturition reflex pathways.
Maggi
C A
CA
Pharmacology Department, A. Menarini Pharmaceuticals, Florence, Italy.
Giuliani
S
S
Giachetti
A
A
Meli
A
A
D000758:Anesthesia; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D003986:Dibenzocycloheptenes / Q000494:pharmacology*; D016291:Dizocilpine Maleate; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000378:metabolism / Q000502:physiology; D012018:Reflex / Q000187:drug effects*; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology; D014554:Urination / Q000187:drug effects*
D003986:Dibenzocycloheptenes; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D016291:Dizocilpine Maleate; D002211:Capsaicin