Effects of Insulin-Like Growth Factors and Transforming Growth Factor- β on the Growth and Differentiation of Muscle Cells in Culture

Conclusion

Thus, we have identified and begun to characterize the actions of two growth factors which appear to play major roles in controlling the growth and differentiation of muscle cells in culture, IGF-I and TGF-β. The IGF stimulate both proliferation and differentiation of muscle cells, and TGF-β is a very potent inhibitor of all aspects of myoblast differentiation. These two growth factors are active not only in mammalian systems, but also appear to modulate the development of avian muscle cells. Studies incorporating the use of IGF-I and TGF-β along with other purified growth factors in serum-free defined medium should yield promising information on the control mechanisms involved in skeletal muscle growth and differentiation.