[Physiology of the GH-IGF axis].
Growth, the main characteristic of childhood and adolescence, has a similar pattern in the majority of the individuals. Genetic background and GH-IGF axis are the factors that directly influence this process. Pituitary GH acts on growth mainly through the regulation of IGF system. The IGFs (IGF-1 and IGF-2) are growth factors produced in the majority of the organs and body tissues. They have autocrine, paracrine and endocrine actions on metabolism and cell proliferation, growth and differentiation. The IGFs bind with high specificity and affinity to a family of 6 binding proteins, called IGFBPs (1 to 6) that modulate their bioactivity. Most of the known IGF actions are mediated via IGF type 1 receptor (IGF1R). In this article we are going to review the composition and regulation of the GH-IGF axis and the role of each component in the regulation of the growth process.
Martinelli
Carlos Eduardo
CE
Departamento de Puericultura e Pediatria, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, SP, Brazil. cemart@fmrp.usp.br
Custódio
Rodrigo José
RJ
Aguiar-Oliveira
Manuel Hermínio
MH
D006128:Growth / Q000502:physiology*; D006130:Growth Disorders / Q000503:physiopathology; D019382:Human Growth Hormone / Q000502:physiology*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D007335:Insulin-Like Growth Factor II / Q000502:physiology; D017526:Receptor, IGF Type 1 / Q000502:physiology; D013002:Somatomedins / Q000502:physiology*
D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D017526:Receptor, IGF Type 1