Mechanisms of baroreceptor activation

M. W. Chapleau, G. Hajduczok, R. V. Sharma, R. E. Wachtel, J. T. Cunningham, M. J. Sullivan, P. M. Abboud

Research output: Contribution to journalArticle

25 Scopus citations

Abstract

The determinants of the nerve activity generated at the baroreceptor endings have been examined. 1) In the isolated carotid sinus, the placement of activated bovine aortic endothelial cells decreased baroreceptor activity (BRA) in a reversible manner. Both endothelin and nitric oxide (NO) suppress BRA, whereas prostacyclin (PGI2) increases activity. 2) The BRA in single units declines and often ceases during non-pulsatile increases in carotid sinus pressure sustained over several minutes. This "adaptation" is attenuated by the transient potassium channel (IA) blocker 4-aminopyridine (4-AP) and not by inhibition of the Na+/K+ pump. 3) In preliminary studies, mechano-electrical transduction was examined in isolated and cultured nodose ganglion neurons. Opening of stretch-activated (SA) channels by suction on the cell-attached patch was seen infrequently; however, probing the neurons consistently increased their intracellular calcium [Ca+plus;]i measured with fura-2. This increase in [Ca+plus;]i is blocked by gadolinium (Gd3+), a trivalent lanthanide reported to block SA channels. Gd3+ also blocks the BRA in the carotid sinus. We conclude that paracrine factors significantly modulate BR sensitivity, that selective ionic mechanisms (the 4-AP sensitive K+ channels) determine the degree of "adaptation" of BR to elevated pressure, and that SA channels sensitive to Gd3+ may be the mechano-electrical transducers in BR neurons.

Original languageEnglish
Pages (from-to)1-13
Number of pages13
JournalClinical and Experimental Hypertension
Volume17
Issue number1-2
DOIs
StatePublished - 1995

Keywords

  • Baroreceptor neurons
  • Baroreceptors
  • Mechano-electrical transduction

Fingerprint Dive into the research topics of 'Mechanisms of baroreceptor activation'. Together they form a unique fingerprint.

  • Cite this

    Chapleau, M. W., Hajduczok, G., Sharma, R. V., Wachtel, R. E., Cunningham, J. T., Sullivan, M. J., & Abboud, P. M. (1995). Mechanisms of baroreceptor activation. Clinical and Experimental Hypertension, 17(1-2), 1-13. https://doi.org/10.3109/10641969509087050