What Are the Different Types of Insulin-Like Growth Factors?

Insulin-like growth factor (IGF) is a group of growth-promoting peptides. Its secreting cells are widely distributed in human liver, kidney, lung, heart, brain, and intestine. The IGF family has two types, IGF-I and IGF-II. The production of IGF-I is more dependent on GH, which has a strong growth promoting effect and is an important growth factor in childhood. IGF-I synthesized in various tissues mostly exerts its growth-promoting effect in an autocrine or paracrine manner, while IGF-I synthesized by the liver enters the blood circulation and acts on target cells in an endocrine manner. IGF- levels are regulated by GH in the body. IGF- also has a negative feedback regulating effect on GH secretion. IGF- is more insulin-like and plays an important role in fetal growth.

Basic Information

Chinese name

Insulin-like growth factor

Foreign name

insulin-like growth factors

Short name

IGFs

Category

Multifunctional cell proliferation regulator

IGF Insulin-like growth factor IGF receptor

The insulin-like growth factor receptor IGF must dissociate from the carrier protein IGF-binding protein (IGFBP) and then bind to its specific receptor to exert its biological effect. IGF receptors are divided into two types, namely, IGF- receptor (IGF-R) and IGF- receptor (IGF-R). The former is a tyrosine kinase-type receptor, which is composed of two subunits. Tetrameric glycoprotein; the latter has no amino acid kinase activity.

IGF Characteristics of insulin-like growth factor IGF

IGF is a multifunctional cell regulatory factor. Most IGFs are synthesized in the liver and are mainly found in the blood circulation. IGF mediates growth hormone stimulation, regulates tissue growth and development, and plays an important role in regulating muscle volume and strength, maintaining body composition, and regulating nutritional metabolism; through endocrine, paracrine, and / or autocrine methods, the target Cell surface receptors IGFR and IGFIIR mediate their biological effects and are regulated by IGF-binding proteins. Most extrahepatic tissues can produce IGF locally, and most of them are not regulated by GH and play an important role in local tissues.

Clinical significance of insulin-like growth factor

IGF may be an important autocrine and paracrine signaling molecule during the development of the central nervous system. IGF- is considered to be a survival factor for glial progenitor cells and oligodendrocytes. Both IGF- and IGF- can be used as myogenic neurotrophic factors to stimulate the growth of intramuscular neurites.