3-Iodothyronamine: a novel hormone controlling the balance between glucose and lipid utilisation

J Comp Physiol B. 2008 Feb;178(2):167-77. doi: 10.1007/s00360-007-0208-x. Epub 2007 Oct 3.

Abstract

3-Iodothyronamine is considered as a derivate of thyroid hormone as a result of enzymatic deiodination and decarboxylation. The physiological role of thyronamine (T1AM) is not known. The aim of this study was to analyze the metabolic response to T1AM in the Djungarian hamster Phodopus sungorus. We measured the influence of T1AM (50 mg/kg) on metabolic rate (VO(2)), body temperature (T (b)) and respiratory quotient (RQ) in this species and in BL/6 mice. T1AM treated hamsters as well as the mice showed a rapid decrease in VO(2) and T (b), accompanied by a reduction of RQ from normal values of about approximately 0.9 to approximately 0.70 for several hours. This indicates that carbohydrate utilisation is blocked by the injection of T1AM and that metabolic pathways are rerouted from carbohydrate to lipid utilisation in response to T1AM. This assumption was further supported by the observation that the treatment of T1AM caused ketonuria and a significant loss of body fat. Our results indicate that T1AM has the potential to control the balance between glucose and lipid utilisation in vivo.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Basal Metabolism / drug effects
  • Basal Metabolism / physiology
  • Blood Glucose / metabolism*
  • Body Composition / drug effects
  • Body Composition / physiology
  • Body Temperature / drug effects
  • Body Temperature / physiology
  • Cricetinae
  • Dietary Carbohydrates / metabolism
  • Dietary Fats / metabolism
  • Energy Metabolism / drug effects
  • Energy Metabolism / physiology
  • Female
  • Ketones / urine
  • Lipid Metabolism / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL / metabolism*
  • Phodopus / metabolism*
  • Photoperiod
  • Seasons
  • Species Specificity
  • Thyronines / metabolism*
  • Thyronines / pharmacology

Substances

  • 3-iodothyronamine
  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Fats
  • Ketones
  • Thyronines