Brown adipose tissue redox status in response to dietary-induced obesity-associated oxidative stress in male and female rats

Abstract

Obesity is linked to systemic oxidative stress and, although brown adipose tissue (BAT) plays a crucial role in energy balance, BAT redox status effects on obesity have not been studied previously. Female rats exhibit a greater BAT thermogenic capacity, attributed to enhanced mitochondrial differentiation, than males. The aim of this study was to investigate whether the mitochondrial sexual dimorphism is related to differences in BAT redox status and to assess its role in the regulation of body weight gain in response to chronic high fat diet (HFD) feeding. Ten-week-old Wistar rats of both genders were fed a pelleted control diet or HFD for 26 weeks. Although mitochondria of female rats produced higher levels of hydrogen peroxide than those of males, females exhibited lower oxidative damage, attributed to greater glutathione peroxidase activity and higher glutathione content. In response to HFD, body weight increased markedly in females, but oxidative capacity increased only in males, thus maintaining improved BAT redox status compared with females. In conclusion, the sexual dimorphism in BAT redox status found in control animals is attenuated by the HFD. The enhanced oxidative capacity of HFD males can be related to their greater resistance to body weight gain.

Keywords::

• Brown adipose tissue
• gender differences
• mitochondria
• obesity
• oxidative stress
• redox status

Acknowledgements

This work was supported by Fondo de Investigaciones Sanitarias of the Spanish Government (PI060293) and by Conselleria d'Innovació i Energia of the Comunitat Autónoma de les Illes Balears (PROGECIB-1C). Nadal-Casellas was funded by a grant from the Comunitat Autònoma de les Illes Balears.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.