Harlow 9808785 The black bear may be a paradox. These animals remain within their winter den for 5 to 7 months at or near normal body temperature. However, in spite of prolonged starvation and confinement, overwintering bears may not show apparent characteristics of skeletal muscle atrophy. The PIs hypothesize that bears under natural winter conditions have no loss of muscle fiber number, size, proportion of oxidative fibers or protein content. The PIs propose to take muscle biopsies from bears and monitor changes in muscle morphology, protein content and protein turnover during early and late winter and midsummer. Bears appear to be capable of rapid and sustained locomotor activity when disturbed at any time during the winter. The PIs will measure strength and activity of the fore and hind- limbs of bears during the winter and summer using noninvasive and nonsubjective methodologies, The prospect that bears can maintain muscle integrity and strength during a period, with no protein intake and tight confinement has the potential to aid doctors in the prescription of treatments that will help humans adjust to conditions such a s prolonged bed rest, limited activity or extended space travel.
