Responses of brown-adipose-tissue activity in the rat to 14 days of spaceflight

Abstract

Abstract The current study was undertaken to investigate the effects of 14 days of spaceflight (SLS-2) on the function of brown adipose tissue (BAT) in male rats. The spaceflight did not seem to have any significant effect on BAT mass or its components (total protein, DNA, RNA, and triglyceride) in the animals ( n = 13). As compared with synchronous controls ( n = 8), the expression of uncoupling protein (UCP) mRNA in BAT of flight rats was enhanced considerably ( P g and came to the same degree 9 days later. Both UCP antigen and guanosine 5′-diphosphate (GDP)-binding values in the mitochondria recovered from BAT of flight rats increased three to four times over those of control rats 9 days after flight, being highly suggestive of an increase in the thermogenic activity of BAT, but not 6 h after flight. These data suggest that spaceflight itself may not have great influence on the function of BAT. Collectively the results suggest that samples, especially BAT, should be obtained in flight as well as after in order to avoid the influences of entry to space, and reentry and readaptation to 1 · g .