Research Paper Volume 8, Issue 9 pp 2062—2080

Figure 1. ITPR1 levels are decreased in aged skeletal muscle. (A) qRT-PCR analysis of mRNA levels of Ca²⁺ regulatory genes, relative to 36b4, in young (6 months) and aged (28 months) mice gastrocnemius muscle. n = 5 for each group. (B) qRT-PCR analysis of Itpr mRNA levels, relative to 36b4, from soleus and TA muscles of young (isolated from 6 month-old mice) and aged (isolated from 28 month-old mice) mice. n = 5 for each group. (C) Immunoblot analysis of ITPR1 protein levels from soleus and TA muscles of young and aged mice, with GAPDH as the loading control. n = 3 for each group. (D) qRT-PCR analysis of mRNA levels of Ca²⁺ regulatory genes, relative to 36b4, in young (isolated from 3 month-old mice) and old (isolated from 28 month-old mice) primary myoblasts. n = 5 for each group. (E) Immunoblot analysis of ITPR1 protein levels in young and old primary myoblasts, with GAPDH as the loading control. (F) Measurement of extracellular ATP (1 mM)-induced Ca²⁺ oscillations in a single myoblast from young and old primary myoblast cultures. F/F0 represents the change in fluorescence normalized to resting fluorescence (F0).