Effect of 5,7-dihydroxytryptamine, ovariectomy and gonadal steroids on serotonin receptor binding in rat brain

Neuroendocrinology. 1994 Mar;59(3):245-50. doi: 10.1159/000126665.

Abstract

Quantitative autoradiography was used to assess alterations in serotonin (5-HT) receptor binding in the hypothalamus and hippocampus following denervation with 5,7-dihydroxytryptamine (5,7-DHT), ovariectomy (OVX) and gonadal steroid manipulation. Seven days after 5,7-DHT injection, 5-HT1a receptor density was significantly increased in the ventromedial hypothalamic nucleus (VMN) of intact but not OVX female rats. Under these conditions 5-HT1b receptor density was unchanged in any brain region examined and 5-HT transporter binding was decreased in all 5,7-DHT injected animals. In addition, there was a significant interaction between OVX and 5,7-DHT for both the 5-HT1a receptor and the 5-HT transporter in the VMN, such that OVX inhibited the 5,7-DHT-induced increase in 5-HT1a receptors and attenuated the 5,7-DHT-induced decrease in 5-HT transporter binding. In a separate experiment the effect of gonadal steroid manipulation on 5-HT receptor binding was assessed. In female OVX rats, 5-HT1a receptor density was unchanged by estrogen or estrogen and progesterone administration. In male rats, castration significantly decreased 5-HT1a receptor density in the medial preoptic area. Estrogen and progesterone administration to female OVX rats increased the density of 5-HT1b receptors in the VMN, as compared to estrogen alone. The relationship of these results to the role of 5-HT in mediating lordosis behavior is discussed.

Publication types

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

MeSH terms

  • 5,7-Dihydroxytryptamine / pharmacology*
  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacokinetics
  • Animals
  • Autoradiography
  • Brain Chemistry / drug effects
  • Brain Chemistry / physiology*
  • Carrier Proteins / metabolism
  • Estrogens / pharmacology
  • Female
  • Gonadal Steroid Hormones / pharmacology*
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Iodocyanopindolol
  • Male
  • Membrane Glycoproteins / metabolism
  • Membrane Transport Proteins*
  • Nerve Tissue Proteins / metabolism
  • Orchiectomy*
  • Ovariectomy*
  • Paroxetine / pharmacokinetics
  • Pindolol / analogs & derivatives
  • Pindolol / pharmacokinetics
  • Progesterone / pharmacology
  • Rats
  • Receptors, Serotonin / drug effects
  • Receptors, Serotonin / metabolism*
  • Receptors, Serotonin / physiology
  • Serotonin Plasma Membrane Transport Proteins
  • Ventromedial Hypothalamic Nucleus / drug effects
  • Ventromedial Hypothalamic Nucleus / metabolism

Substances

  • Carrier Proteins
  • Estrogens
  • Gonadal Steroid Hormones
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Nerve Tissue Proteins
  • Receptors, Serotonin
  • Serotonin Plasma Membrane Transport Proteins
  • Slc6a4 protein, rat
  • 5,7-Dihydroxytryptamine
  • Paroxetine
  • Progesterone
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Iodocyanopindolol
  • Pindolol