Somatomedins and other serum growth factors: a review of current concepts.

Growth hormone is essential for sustaining longitudinal growth in man. However, during the last 20 years, it has become evident that the actions of growth hormone, at a cellular level, are mediated by specific growth promoting factors. This paper describes the nature and actions of mammalian growth factors and summarises the immense contribution that the measurement of these substances has made towards the elucidation of many problems in the science of human growth and development.