Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1989 Sep;416:67–78. doi: 10.1113/jphysiol.1989.sp017749

Baroreceptor-vasomotor reflex after N-methyl-D-aspartate receptor blockade in rabbit caudal ventrolateral medulla.

W W Blessing 1
PMCID: PMC1189203  PMID: 2575166

Abstract

1. Experiments were performed in anaesthetized rabbits to determine whether blockade of N-methyl-D-aspartate receptors in the caudal ventrolateral medulla oblongata prevents the changes in renal sympathetic vasomotor activity which normally occur in response to increases or decreases in arterial pressure. 2. N-Methyl-D-aspartic acid receptor blockade using bilateral injections of either kynurenic acid (5 nmol) or DL-amino-5-phosphonovaleric acid (5 nmol) caused a rise in arterial pressure with a variable change in renal sympathetic nerve activity. 3. The depressor and renal sympathoinhibitory responses normally seen after intramedullary injection of N-methyl-D-aspartic acid (50 pmol) into the caudal ventrolateral medulla were entirely prevented by prior receptor blockade. The corresponding responses to L-glutamate (10 nmol) were not affected. 4. The depressor and renal sympathoinhibitory responses normally seen with electrical stimulation of the aortic depressor nerve were abolished by the receptor blockade. 5. The reflex inhibition of renal sympathetic nerve activity normally seen in response to increasing arterial pressure using a cuff around the descending aorta was not affected by kynurenic acid. The response was reduced by DL-amino-5-phosphonovaleric acid but a significant degree of inhibition was preserved. The reflex increase in renal sympathetic nerve activity normally seen in response to reducing arterial pressure using a cuff occluder around the inferior vena cava was unchanged after injection of DL-amino-5-phosphonovaleric acid and was increased in magnitude after injection of kynurenic acid. 6. The results indicate that blockade of excitatory amino acid receptors in the caudal ventrolateral medulla of the rabbit abolishes the depressor response evoked by electrical stimulation of the aortic nerve but leaves intact the normal baroreceptor-vasomotor responses elicited by raising or lowering arterial pressure.

Full text

PDF
67

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Blessing W. W. Depressor neurons in rabbit caudal medulla act via GABA receptors in rostral medulla. Am J Physiol. 1988 Apr;254(4 Pt 2):H686–H692. doi: 10.1152/ajpheart.1988.254.4.H686. [DOI] [PubMed] [Google Scholar]
  2. Blessing W. W., Reis D. J. Inhibitory cardiovascular function of neurons in the caudal ventrolateral medulla of the rabbit: relationship to the area containing A1 noradrenergic cells. Brain Res. 1982 Dec 16;253(1-2):161–171. doi: 10.1016/0006-8993(82)90683-7. [DOI] [PubMed] [Google Scholar]
  3. Blessing W. W., Willoughby J. O. Depressor neurons in rabbit caudal medulla do not transmit the baroreceptor-vasomotor reflex. Am J Physiol. 1987 Oct;253(4 Pt 2):H777–H786. doi: 10.1152/ajpheart.1987.253.4.H777. [DOI] [PubMed] [Google Scholar]
  4. Blessing W. W., Willoughby J. O. Inhibiting the rabbit caudal ventrolateral medulla prevents baroreceptor-initiated secretion of vasopressin. J Physiol. 1985 Oct;367:253–265. doi: 10.1113/jphysiol.1985.sp015823. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dampney R. A., Blessing W. W., Tan E. Origin of tonic GABAergic inputs to vasopressor neurons in the subretrofacial nucleus of the rabbit. J Auton Nerv Syst. 1988 Oct;24(3):227–239. doi: 10.1016/0165-1838(88)90123-3. [DOI] [PubMed] [Google Scholar]
  6. Gordon F. J. Aortic baroreceptor reflexes are mediated by NMDA receptors in caudal ventrolateral medulla. Am J Physiol. 1987 Mar;252(3 Pt 2):R628–R633. doi: 10.1152/ajpregu.1987.252.3.R628. [DOI] [PubMed] [Google Scholar]
  7. Granata A. R., Ruggiero D. A., Park D. H., Joh T. H., Reis D. J. Brain stem area with C1 epinephrine neurons mediates baroreflex vasodepressor responses. Am J Physiol. 1985 Apr;248(4 Pt 2):H547–H567. doi: 10.1152/ajpheart.1985.248.4.H547. [DOI] [PubMed] [Google Scholar]
  8. Guyenet P. G., Filtz T. M., Donaldson S. R. Role of excitatory amino acids in rat vagal and sympathetic baroreflexes. Brain Res. 1987 Mar 31;407(2):272–284. doi: 10.1016/0006-8993(87)91105-x. [DOI] [PubMed] [Google Scholar]
  9. Kubo T., Kihara M. N-methyl-D-aspartate receptors mediate tonic vasodepressor control in the caudal ventrolateral medulla of the rat. Brain Res. 1988 Jun 7;451(1-2):366–370. doi: 10.1016/0006-8993(88)90786-x. [DOI] [PubMed] [Google Scholar]
  10. Numao Y., Saito M., Terui N., Kumada M. Physiological and pharmacological properties of the three subsystems constituting the aortic nerve-renal sympathetic reflex in rabbits. J Auton Nerv Syst. 1983 Nov;9(2-3):361–380. doi: 10.1016/0165-1838(83)90002-4. [DOI] [PubMed] [Google Scholar]
  11. Olney J. W., Labruyere J., Collins J. F., Curry K. D-aminophosphonovalerate is 100-fold more powerful than D-alpha-aminoadipate in blocking N-methylaspartate neurotoxicity. Brain Res. 1981 Sep 21;221(1):207–210. doi: 10.1016/0006-8993(81)91076-3. [DOI] [PubMed] [Google Scholar]
  12. Stone T. W., Connick J. H. Quinolinic acid and other kynurenines in the central nervous system. Neuroscience. 1985 Jul;15(3):597–617. doi: 10.1016/0306-4522(85)90063-6. [DOI] [PubMed] [Google Scholar]
  13. Willette R. N., Barcas P. P., Krieger A. J., Sapru H. N. Vasopressor and depressor areas in the rat medulla. Identification by microinjection of L-glutamate. Neuropharmacology. 1983 Sep;22(9):1071–1079. doi: 10.1016/0028-3908(83)90027-8. [DOI] [PubMed] [Google Scholar]
  14. Willette R. N., Krieger A. J., Barcas P. P., Sapru H. N. Medullary gamma-aminobutyric acid (GABA) receptors and the regulation of blood pressure in the rat. J Pharmacol Exp Ther. 1983 Sep;226(3):893–899. [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES