The serotonin transporter is present and functional in peripheral arterial smooth muscle

J Cardiovasc Pharmacol. 2004 Jun;43(6):770-81. doi: 10.1097/00005344-200406000-00006.


We tested the hypothesis that the 5-HT transporter (5-HTT) is present and functional in peripheral arterial smooth muscle. In aorta and mesenteric resistance arteries, real time RT-PCR and western analyses indicated the presence of 5-HTT mRNA and a 74 kDa 5-HTT protein. Immunohistochemistry localized the transporter to smooth muscle and endothelial cells. 5-HT and the metabolite 5-hydroxyindole acetic acid (5-HIAA) were detected in aorta, carotid, and superior mesenteric arteries using HPLC; the MAOA inhibitor pargyline significantly increased (over 400%) arterial 5-HT concentration. 5-HT was taken up by arteries in a time-dependent manner and uptake was independent of the endothelium, sympathetic nerves, and norepinephrine transporter. 5-HT-induced contraction of normal aorta was potentiated by the 5-HTT inhibitor fluvoxamine. A change in arterial 5-HTT function occurs in deoxycorticosterone (DOCA)-salt hypertension as the potency and threshold of 5-HT in contracting aorta from the DOCA-salt rat was increased by fluoxetine and fluvoxamine (1 micromol/L; DOCA fluvoxamine -log EC50 [mol/L] = 6.85 +/- 0.08, DOCA-control = 6.44 +/- 0.08); expression of transporter was significantly increased in aorta of DOCA salt rats (145% Sham). These studies show for the first time the presence of the 5-HTT in peripheral arterial smooth muscle and raise the question as to the function of the 5-HTT in regulating peripheral effects of 5-HT.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Aorta, Thoracic / physiology*
  • Carrier Proteins / physiology*
  • Desoxycorticosterone / toxicity
  • Humans
  • Hypertension / chemically induced
  • Hypertension / metabolism
  • Hypertension / physiopathology
  • In Vitro Techniques
  • Male
  • Membrane Glycoproteins / physiology*
  • Membrane Transport Proteins*
  • Mesenteric Arteries / physiology*
  • Muscle, Smooth, Vascular / physiology*
  • Nerve Tissue Proteins / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Serotonin / metabolism
  • Serotonin Plasma Membrane Transport Proteins


  • Carrier Proteins
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Nerve Tissue Proteins
  • SLC6A4 protein, human
  • Serotonin Plasma Membrane Transport Proteins
  • Slc6a4 protein, rat
  • Serotonin
  • Desoxycorticosterone