African Journal of
Biochemistry Research

  • Abbreviation: Afr. J. Biochem. Res.
  • Language: English
  • ISSN: 1996-0778
  • DOI: 10.5897/AJBR
  • Start Year: 2007
  • Published Articles: 408

Full Length Research Paper

Thermogenic response of guinea pig adipocytes to noradrenaline and β3-AR agonists

Ghorbani Masoud1* and Mehdi Shafiee Ardestani2
1Department of Research and Development, Pasteur Institute of Iran (Research and Production complex), 25th km Tehran Karaj Highway, Tehran, Iran. 2Department of Hepatitis and Aids, Pasteur Institute of Iran, Tehran, Iran.
Email: [email protected]

  •  Published: 31 May 2012

Abstract

Brown adipocytes isolated from warm acclimated guinea pig do not respond to noradrenaline (NA) in spite of their marked thermogenic response in vivo. In contrast, in cold-acclimated guinea pigs, isolated brown adipocytes show substantial increase in capacity for a thermogenic response to NA. Chronic stimulation with a β3-AR agonist increased insulin-sensitivity of brown adipose tissue (BAT) in the guinea pig. To investigate the responsiveness of glucose transport to insulin, to NA, and to β3-AR agonists, we used BAT of guinea pigs as an animal known to be insulin-resistant. Results of this study showed that no β3-adrenergic agonist used, such as CL 316,243, BRL 37344, was able to stimulate oxygen uptake in BAT cells from cold-acclimated or new born guinea pigs. However, noradrenaline (NA), adrenaline (A) and isoproterenol (ISO) had a marked thermogenic effect on these cells. In contrast, in a comparative study in warm-acclimated rat BAT cells, CL 316,243 was even more potent than NA in stimulating oxygen uptake. We concluded that guinea pigs lack β3-ARs in their BAT. These results were interesting and noteworthy, suggesting that guinea pigs can be a natural model for β3-ARs knockout.

 

Key words: Brown adipose tissue (BAT), White adipose tissue (WAT), β3-ARs, guinea pig.