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 10

Apoptotic index and muscle fiber size. (a) The apoptotic index was calculated from tissue cross sections of the EDL muscle by determining the number ratio of TUNEL-positive nuclei to total nuclei in EDL cross sections from muscles of control animals for the hindlimb suspension group (HS Con), the recovery group (R Con), and in experimental animals after 14 days of hindlimb suspension (HS) or after 14 days of hindlimb suspension followed by 14 days of reloading (R). Only nuclei that were directly below or touching the basal lamina were counted. Therefore, this evaluation included both satellite cell and myonuclear cell populations. The animals received either Ca-HMB or water daily by gavage. A MANOVA followed by Bonferroni’s post hoc analyses were used to evaluate the differences between the group means; ^†, HS or R vs. control animals for that experimental condition. (b) Fiber cross-sectional area (CSA) was obtained by planimetry in the EDL muscles of control animals for the hindlimb suspension group (HS Con), the recovery group (R Con), and in experimental animals after 14 days of hindlimb suspension (HS), or after 14 days of hindlimb suspension followed by 14 days of reloading (R). The animals received Ca-HMB or water daily by gavage. A MANOVA followed by Bonferroni’s post hoc analyses were used to evaluate the differences between the group means. The data are presented as .

(a)

(b)