Figure 4.

Alteration of connective tissue progenitor (CTP) frequency and osteogenic differentiation after rapamycin treatment. Shown is the frequency of CTPs in muscle tissue isolated from naïve, vehicle-, or rapamycin-treated injured rats (minus methicillin-resistant Staphylococcus aureus infection) at postoperative day 7, cultured either in growth (stromal) media (SM) or osteogenic media (OM) for 1 week (A) and early osteogenic differentiation of CTPs in SM or OM, as measured by p-nitrophenyl phosphate–based alkaline phosphatase activity assay (B). ^∗P < 0.05 versus vehicle control (two-tailed t-test).