Different adrenal sympathetic preganglionic neurons regulate epinephrine and norepinephrine secretion

Shaun F. Morrison, Wei Hua Cao

Research output: Contribution to journalArticle

109 Scopus citations

Abstract

Brain stimulation or activation of certain reflexes can result in differential activation of the two populations of adrenal medullary chromaffin cells: those secreting either epinephrine or norepinephrine, suggesting that they are controlled by different central sympathetic networks. In urethan-chloralose-anesthetized rats, we found that antidromically identified adrenal sympathetic preganglionic neurons (SPNs) were excited by stimulation of the rostral ventrolateral medulla (RVLM) with either a short (mean: 29 ms) or a long (mean: 129 ms) latency. The latter group of adrenal SPNs were remarkably insensitive to baroreceptor reflex activation but strongly activated by the glucopenic agent 2-deoxyglucose (2-DG), indicating their role in regulation of adrenal epinephrine release. In contrast, adrenal SPNs activated by RVLM stimulation at a short latency were completely inhibited by increases in arterial pressure or stimulation of the aortic depressor nerve, were unaffected by 2-DG administration, and are presumed to govern the discharge of adrenal norepinephrine-secreting chromaffin cells. These findings of a functionally distinct preganglionic innervation of epinephrine- and norepinephrine-releasing adrenal chromaffin cells provide a foundation for identifying the different sympathetic networks underlying the differential regulation of epinephrine and norepinephrine secretion from the adrenal medulla in response to physiological challenges and experimental stimuli.

Original languageEnglish (US)
Pages (from-to)R1763-R1775
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume279
Issue number5 48-5
StatePublished - Dec 12 2000

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Keywords

  • 2-deoxyglucose
  • Adrenal medulla
  • Blood pressure
  • Hypoglycemia
  • Intermediolateral nucleus
  • Rostral ventrolateral medulla
  • Splanchnic nerve activity
  • Sympathetic nerve activity
  • Vasoconstrictor neurons

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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