C - Michigan Technological University

further assays. To determine whether bear serum had a seasonal effect in response toapoptotic threat, MC3T3-E1 pre-osteoblasts were primed for 24 hours in seasonal bearserum, then serum starved for 6 hours. The caspase-3/7 response to 6 hours’ serumstarvation was graphed longitudinally with a smoothed average curve (Figure 5.2). Thecaspase-3/7 response began to decrease in serum collected approximately 10 daysbefore hibernation, and remained at a lower level throughout hibernation. In serumcollected just after hibernation, caspase-3/7 response immediately rose to levels higherthan those stimulated by prehibernation serum, suggesting a state of increasedosteoblast metabolism in post-hibernation. When samples were grouped by season andcompared by ANOVA, caspase-3/7 activity dropped from 5.66+0.23 relative units in fallto 3.82+0.20 in winter; values then rose to 7.89+0.41 in the spring (p