Two factors that may determine brown adipose tissue (BAT) hypertrophy during conditions of increased metabolic heat production are increased food intake and increased sympathetic nervous system (SNS) activity. Since these two proceed pari passu during cold exposure, their independent contributions to BAT hypertrophy are unknown. To examine the role of each, we limited the food intake of a group of a cold exposed rats by pair feeding them to warm exposed control rats and then compared the pair fed rats to ad lib fed cold exposed animals. Restricted food intake limited absolute BAT hypertrophy (0.226±0.01 g. vs 0.488±0.02 g, pair fed vs ad lib, P<0.01), BAT as per cent body weight (0.189±0.12 vs 0.252±0.012, P<0.01) and BAT protein content (34.4±3.8 vs 48.9±2.6 mg, P<0.01) despite evidence of quantitatively similar activation of the SNS in BAT in both groups. We conclude that increased food intake contributes to BAT hypertrophy in cold exposure independent of sympathetic activity.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)