Serotonin 2A receptors modulate tail-skin temperature in two rodent models of estrogen deficiency-related thermoregulatory dysfunction

Brain Res. 2004 Dec 3;1028(2):191-202. doi: 10.1016/j.brainres.2004.09.012.

Abstract

Menopause-associated thermoregulatory dysfunction, including hot flushes and night sweats, is effectively treated by hormonal therapies that include estrogens. Evidence suggests that estrogen regulates serotonin 2A (5-HT(2A)) receptor expression and that 5-HT(2A) receptors are involved in thermoregulation. Therefore, the role of 5-HT(2A) receptors in thermoregulation was assessed in two rat models of ovariectomy-induced thermoregulatory dysfunction. The first model is based on measurement of the tail-skin temperature (TST) increase following naloxone-induced withdrawal in morphine-dependent ovariectomized (OVX) rats (MD model), while the second model relies on telemetric assessment of diurnal TST changes in ovariectomized rats (telemetry model). Treatment with a 5-HT(2A/2C) receptor agonist, (-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI), prevented the naloxone-induced TST increase in the MD model and restored normal active-phase TST in the telemetry model. The selective 5-HT(2A) receptor antagonist, MDL-100907, had no effect on the naloxone-induced flush when administered alone in the MD model, but it decreased DOI's ability to abate the flush. In the telemetry model, MDL-100907 attenuated the DOI-induced decrease in active-phase TST. Interestingly, MDL-100907 increased TST in both models when given alone, with the TST increase occurring prior to the naloxone-induced flush in the MD model. To evaluate the role of central nervous system (CNS) 5-HT(2A) receptors in TST regulation, DOI was administered in combination with a known peripheral 5-HT(2A/2C) receptor antagonist, xylamidine, in the MD model. Xylamidine had no effect on DOI's ability to abate the naloxone-induced flush. These results indicate that activation of central 5-HT(2A) receptors restores temperature regulation in two rodent models of ovariectomy-induced thermoregulatory dysfunction.

Publication types

  • Comparative Study

MeSH terms

  • Amidines / pharmacology
  • Amphetamines / pharmacology
  • Animals
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Endocrine System Diseases / etiology
  • Endocrine System Diseases / metabolism
  • Endocrine System Diseases / physiopathology*
  • Estradiol / pharmacology
  • Estrogens / deficiency*
  • Female
  • Fluorobenzenes / pharmacology
  • Naloxone / adverse effects
  • Ovariectomy / methods
  • Piperidines / pharmacology
  • Rats
  • Reaction Time / drug effects
  • Receptor, Serotonin, 5-HT2A / physiology*
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / pharmacology
  • Skin Temperature / drug effects
  • Skin Temperature / physiology*
  • Substance Withdrawal Syndrome / complications
  • Substance Withdrawal Syndrome / metabolism
  • Substance Withdrawal Syndrome / physiopathology
  • Telemetry / methods
  • Time Factors

Substances

  • Amidines
  • Amphetamines
  • Estrogens
  • Fluorobenzenes
  • Piperidines
  • Receptor, Serotonin, 5-HT2A
  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • Naloxone
  • Estradiol
  • volinanserin
  • xylamidine
  • 4-iodo-2,5-dimethoxyphenylisopropylamine