Araghi-Niknam M, Lane L, Watson R R
Arizona Prevention Center, University of Arizona, Tucson, Arizona 85724, USA.
Proc Soc Exp Biol Med. 1999 Jul;221(3):193-7. doi: 10.1046/j.1525-1373.1999.d01-76.x.
As old age results in reduced physical activity as well as less dehydroepiandrosterone (DHEA) and melatonin (MLT) production, low hormone levels may be a component of inactivity. Therefore, we studied the effects of DHEA and/or MLT supplementation on movement and resting in young and old female C57 black mice. Our results showed for the first time that old female C56BL/6 mice have significantly decreased physical activity. Their average speed and resting time were significantly higher than in young mice, whereas ambulatory time, distance traveled, and body movements when stationary (stereo time) were lower. DHEA supplementation significantly increased stereo time in old mice, while decreasing ambulatory time and distance traveled. MLT supplementation of old mice decreased average speed, resting time, and stereo time compared to untreated, old mice. Supplementation with MLT or DHEA, whose production is reduced in aging, restored physical activity levels in old mice. MLT also increased ambulatory time and distance traveled while reducing body movements of young mice.
