The serotonin transporter is required for stress-evoked increases in adrenal catecholamine synthesis and angiotensin II AT2 receptor expression

I. Armando, O. A. Tjurmina, Q. Li, D. L. Murphy, J. M. Saavedra

Research output: Contribution to journalArticlepeer-review

Abstract

High numbers of serotonin transporter (SERT) binding sites and high serotonin (5-HT) content are expressed in the adrenal medulla of wild-type (SERT+/+) mice. Acute restraint stress increases adrenomedullary 5-HT, norepinephrine (NE) and epinephrine (E) release, adrenomedullary tyrosine hydroxylase (TH) mRNA, and angiotensin II AT2 receptor expression. There are no alterations in adrenal catecholamine content during restraint. In litter-mate SERT-/- mice, which do not express SERT binding sites, the basal adrenomedullary 5-HT content is significantly reduced and does not increase after stress. The stress-induced increase in plasma E is higher in SERT-/- than in SERT+/+ animals. In SERT-/- mice, the stress-induced increase in expression of TH mRNA does not occur, and as a consequence, adrenal E content decreases, and adrenal E and NE content are lower than that of SERT+/+ mice during restraint. In addition, instead of increased expression, stress induces a profound decrease in the number of adrenomedullary AT2 receptors in SERT-/- mice. Our results indicate that SERT is necessary for the stress-induced increase in adrenomedullary catecholamine synthesis and AT 2 receptor expression. These data further indicate a close relationship between the adrenomedullary 5-HT and angiotensin II systems, and an important role of adrenomedullary AT2 receptors in catecholamine synthesis and release during stress.

Original languageEnglish (US)
Pages (from-to)217-225
Number of pages9
JournalNeuroendocrinology
Volume78
Issue number4
DOIs
StatePublished - 2003
Externally publishedYes

Keywords

  • Adrenal medulla
  • Angiotensin receptors
  • Angiotensins
  • Catecholamines
  • In situ hybridization
  • Serotonin
  • Serotonin transporter
  • Stress
  • Tyrosine hydroxylase

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience

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