Inhibition by glutamate antagonists, MK-801 and NBQX, of cutaneo-cardiovascular pain reflex in rats.
In urethane-anesthetized rats, xylene applied locally to the skin of the hind paws was shown to induce reflex increases of blood pressure (33%) and heart rate (37%). The blood pressure elevation was dose dependently inhibited by the NMDA antagonist, MK-801 (0.3-1.0 mg/kg i.v.), and by the AMPA (D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxalonepropionic acid) antagonist, NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline 0.1-1.0 mg/kg per min). In contrast, only the latter compound was shown to block dose dependently the observed increase in heart rate. The results suggest that the two glutamate antagonists inhibit nociceptive impulse traffic at distinct anatomical sites and/or by different modes of actions.
Olsen
U B
UB
Department of Pharmacology, CNS Division, Novo Nordisk A/S, Måløv, Denmark.
Lund
A
A
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System / Q000187:drug effects; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D010146:Pain / Q000503:physiopathology*; D011433:Propranolol / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D018091:Receptors, AMPA; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors / Q000502:physiology; D012018:Reflex / Q000187:drug effects*; D012867:Skin / Q000187:drug effects; D012879:Skin Physiological Phenomena
D011810:Quinoxalines; D018091:Receptors, AMPA; D017981:Receptors, Neurotransmitter; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D016291:Dizocilpine Maleate; D011433:Propranolol