Poly-unsaturated fatty acids recruit brown adipose tissue: increased ucp content and nst capacity. Sadurskis, Aija, Andrea Dicker, Barbara Cannon, and Jan Nedergaard. The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, S-106 91 Stockholm, Sweden
APStracts 2:0069E, 1995.
To examine the effect of poly-unsaturated fatty acids (PUFA) on brown adipose tissue recruitment and on the capacity for nonshivering thermogenesis, mice were fed a diet with a standard fat content (9%) and a normal PUFA content (1.8%) (controls) or a high-PUFA content (4.5%) for 2-3 weeks. The resting metabolic rate was somewhat lower in the high-PUFA group (probably due to a lower physical activity), while the capacity for nonshivering thermogenesis (estimated as the metabolic response to a norepinephrine injection) was higher in the high-PUFA group. There was no significant effect on brown adipose tissue wet weight, protein content or cytochrome-c oxidase content, but the amount of the uncoupling protein thermogenin (UCP) (measured immunologically) was significantly increased in the high-PUFA mice (totally by 41%). It was concluded that short-term feeding of a high -PUFA diet may recruit brown adipose tissue thermogenic capacity; it was speculated that earlier reported recruiting effects of high-fat diets may not solely be due to the high total fat content of the diet but may (also) be due to a specific recruiting property of the high -PUFA diets generally used in this type of investigation.

Received 8 December 1994; accepted in final form 30 March 1995.
APS Manuscript Number E508-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 19 April 1995.