1. 1. In Experiment I(fall/winter), hamsters exposed to cold and short photoperiod entered hibernation; hamsters exposed to cold and long photoperiod did not. 2. 2. Hibernators had reduced body masses, significantly atrophied skeletal muscles, but increased mass-specific maximum activities of citrate synthase (an indicator of aerobic capacity) and HOAD (an indicator of β-oxidation). 3. 3. In Experiment II (winter/spring), hamsters were similarly exposed to cold and either long or short photoperiods, but none hibernated. 4. 4. No differences occurred in skeletal muscle masses or enzymatic activities of these two nonhibernating groups in Experiment II. 5. 5. Thus, photoperiod per se does not appear to elicit the skeletal muscle changes seen in the hibernating hamsters; nor are these changes comparable to those seen during bed or limb immobilization.
- Mesocricetus auratus
- oxidative capacity
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)