The Effects of Calcium-β-Hydroxy-β-Methylbutyrate on Aging-Associated Apoptotic Signaling and Muscle Mass and Function in Unloaded but Nonatrophied Extensor Digitorum Longus Muscles of Aged Rats

Figure 9

Apoptotic nuclei after recovery. Top row: representative tissue sections from the soleus muscle, with fluorescent staining for TUNEL (green) to identify apoptotic nuclei in control muscles and muscles after 14 days of hindlimb suspension followed by 14 days of reloading (R). DAPI identified all nuclei (blue). The basal lamina (red) was identified to confirm that the TUNEL-positive nuclei were myonuclei. The conditions were vehicle control for reloaded animals (Water R control), Ca-HMB control for reloaded animals (Ca-HMB con), vehicle reloaded after 14 days of HS and 14 days of reloading (Vehicle reloaded), and Ca-HMB after 14 days of HS followed by 14 days of reloading (Ca-HMB reloaded). The arrows show TUNEL-positive nuclei lying below or immediately adjacent to the basal lamina of the muscle fibers. Bottom row: a higher magnification showing the individual markers for TUNEL, laminin, DAPI, and the combined images. The arrows show TUNEL-positive nuclei lying below or immediately adjacent to the basal lamina of the muscle fibers.