Shivering and nonshivering thermogenesis in exercised cold-deacclimated XXXX .

@entity1169 @entity26 @entity1050 @entity35 @entity1063
@entity1063 (NE)-induced increase in @entity26 consumption (VO2) and colonic temperature (Tc) was greater in cold-acclimated @entity35 housed at 4 degrees C for 4 weeks (CA) than warm-acclimated controls housed at 24 degrees C for 4 weeks (WA). On the other hand, shivering activity measured at 4 degrees C was less in CA than in WA, while @entity1169 administration eliminated the difference between these two groups by enhancing shivering in CA. Wet weight and protein content of interscapular brown adipose tissue (IBAT) were greater in CA than in WA. Following cold acclimation, CA were deacclimated at 24 degrees C for 5 weeks. During deacclimation, half of this latter group were forced to run (15 m.min-1 for 1 h) every day ( @entity1050 ) while the remaining @entity35 remained sedentary (CD-S). Shivering activity assessed at 4 degrees C 4 weeks after commencing cold deacclimation was significantly less in @entity1050 than in CD-S and the difference disappeared following @entity1169 injection. VO2 and Tc responses to NE injection measured 1, 2 and 5 weeks after commencing cold deacclimation did not differ between CD-S and @entity1050 . Although IBAT weight was lighter in @entity1050 than in CD-S, its total protein content was not different between the latter two groups of @entity35 . These results suggest that a greater degree of NE-independent nonshivering thermogenesis (NST) is retained in @entity35 that are exercised during the process of deacclimation as compared with animals that are sedentary. This difference in NST would not seem to be directly related to BAT thermogenic capacity.
