Fig. 4. WtIGFBP-5 and mutIGFBP-5 inhibit apoptosis in myoblasts. (A) Flow cytometric determination of the percentage of annexin V-positive, PI-negative myoblasts transfected with either control vector (C), wtIGFBP-5 (wtBP5) or mutIGFBP-5 (mutBP5) as an indication of apoptosis levels in C2 myoblasts after 24 hours in DM; mean±s.e.m., n=3; ^*P<0.05 compared with control vector; ^**P<0.01 compared with control vector. (B) Caspase-3 activity in myoblast lysates after transfection as in A, expressed as a fraction of control vector transfected cells at each time point after transfer to DM; means±s.e.m., n=3; significance that mean is less than 1.0: ^*P<0.05; ^**P<0.01.