Non-vagal apnea evoked by intra-common carotid artery injection of N-methyl-D-aspartic acid (NMDA) in anesthetized rats.
Respiratory effects of an intra-common carotid artery injection of N-methyl-D-aspartic acid (NMDA) were investigated in anesthetized spontaneously breathing rats, using three experimental paradigms: (1) midcervical vagotomy followed by supranodosal vagotomy, (2) midcervical vagotomy followed by section of the carotid sinus nerves (CSNs), and (3) midcervical vagotomy followed by pharmacological blockade of NMDA receptors. The intra-common carotid artery injection of NMDA (4 mg/kg) induced transient expiratory apnea followed by a brief and variably occurring period of breathing at reduced tidal volume. There were no consistent changes in respiratory rate in rats subjected to midcervical vagotomy alone. Supranodose vagotomy exerted no effect on NMDA-induced respiratory arrest, whereas CSNs' section or blockade of NMDA receptors with AP-7 abolished the apnea. These results indicate that the apnea induced by intra-arterial NMDA challenge is due to activation of peripheral NMDA receptors and is mediated via carotid body afferents.
Kaczyńska
Katarzyna
K
Laboratory of Respiratory Reflexes PAS Medical Research Center, 5 Pawińskiego St., 02-106 Warsaw, Poland.
Szereda-Przestaszewska
Małgorzata
M
Chrapusta
Stanisław J
SJ
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives / Q000494:pharmacology; D000704:Analysis of Variance; D000758:Anesthesia; D000818:Animals; D001049:Apnea / Q000139:chemically induced* / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002346:Carotid Sinus / Q000294:innervation; D003714:Denervation / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007269:Injections, Intra-Arterial / Q000379:methods; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012119:Respiration / Q000187:drug effects; D014628:Vagotomy / Q000379:methods; D014630:Vagus Nerve / Q000502:physiology
D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; C031231:2-amino-7-phosphonoheptanoic acid