N-methyl-D-aspartate receptors but not non-N-methyl-D-aspartate receptors mediate hypertension induced by carotid body chemoreceptor stimulation in the rostral ventrolateral medulla of the rat.
In urethane-anesthetized rats, excitatory amino acid antagonists were microinjected into the rostral ventrolateral medulla (RVLM) and their effects on the pressor response and tachycardia evoked by carotid chemoreceptor stimulation were examined. Microinjections of the N-methyl-D-aspartate (NMDA) receptor antagonists 2-amino-5-phosphonovalerate (AP5) and MK-801 into the RVLM inhibited these chemoreceptor reflex responses whereas these responses were not affected by injection of the non-NMDA receptor antagonist CNQX. AP5 and MK-801 but not CNQX abolished the pressor response evoked by NMDA whereas CNQX but not AP5 and MK-801 abolished that evoked by AMPA or kainate. These results provide evidence that NMDA receptors in the RVLM of the rat are involved in the carotid chemoreceptor reflex.
Kubo
T
T
Department of Pharmacology, Showa College of Pharmaceutical Sciences, Tokyo, Japan.
Amano
M
M
Asari
T
T
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002344:Carotid Body / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D008845:Microinjections; D051381:Rats; D017208:Rats, Wistar; D017459:Receptors, Amino Acid / Q000187:drug effects / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*; D013238:Stereotaxic Techniques; D013268:Stimulation, Chemical
D017459:Receptors, Amino Acid; D016194:Receptors, N-Methyl-D-Aspartate