The N-methyl-D-aspartate (NMDA) receptor antagonist MK-801, attenuates the Bezold-Jarisch reflex in the anaesthetized rat.

The effects of MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, on the Bezold-Jarisch reflex elicited by i.v. doses of 5-hydroxytryptamine (5-HT) was investigated in urethane-anaesthetized rats. Activation of the Bezold-Jarisch reflex with 5-HT (0.5-16 microgram/kg) produced pronounced dose-dependent hypotensive and bradycardic responses which were attenuated by MK-801 (1 mg/kg, i.v.) but not by saline. The data suggests that activation of the Bezold-Jarisch reflex by 5-HT involves a glutamatergic synapse presumably located within the brainstem vagal reflex arc.