The effect of temperature acclimation on the spin-lattice relaxation time of brown adipose tissue.

Cold acclimation induced an increase of spin-lattice relaxation time (T1) of proton nuclear magnetic resonance in rat brown adipose tissue with concomitant increase of water content, while heat acclimation did not effect T1 of this tissue, although its water content was significantly decreased. Temperature acclimation did not affect either T1 or water content of neck muscle.