Biomaterial Database

Controlling insulin-like growth factor activity and the modulation of insulin-like growth factor binding protein and receptor binding. 1998

R H McCusker

Department of Animal Sciences, University of Illinois, Urbana 61801, USA.

The insulin-like growth factors (IGF) and insulin perform seemingly unique roles by causing the same metabolic effect: cellular hypertrophy. Although overlapping, there are different consequences to cellular hypertrophy induced by IGF and that induced by insulin. The IGF enhance the cell hypertrophy that is requisite for cell survival, hyperplasia, and differentiation, and insulin enhances cell hypertrophy primarily as a means to increase nutrient stores. The effects of IGF and insulin are controlled by the segregation of their receptors between different cell types. A model is discussed that describes the need for three hormones (IGF-I, IGF-II, and insulin) to control nutrient partitioning. Insulin receptor localization, as well as an episodic mode of secretion, evolved to perform the short-term action of clearing excess nutrients from the circulation. In contrast, a complex and interactive set of factors ensure that maximal IGF activity occurs only when conditions are optimal for growth. A relatively invariant rate of secretion and the IGF binding proteins serve to maintain a large mutable pool of IGF. This pool exists to ensure a constant supply of IGF to maintain the basal metabolic rate and to ensure that, once a cell begins to proliferate or differentiate, adequate exposure is available to complete the process even after severe short-term physiological insults. The IGF concentrations only change in response to prolonged differences in protein and energy availabilities, environmental and body temperatures, and external stress. Also, evidence is now emerging that describes a discrete role for trace nutrients in the regulation of IGF activity. In this latter regard, zinc has the notable role of targeting IGF binding proteins to the cell surface. New data are presented showing that zinc also changes the affinity of the type 1 IGF receptor and cell-associated IGF binding proteins to optimize IGF activity.

UI	MeSH Term	Description	Entries
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007334	Insulin-Like Growth Factor I	A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on GROWTH HORMONE. It is believed to be mainly active in adults in contrast to INSULIN-LIKE GROWTH FACTOR II, which is a major fetal growth factor.	IGF-I,Somatomedin C,IGF-1,IGF-I-SmC,Insulin Like Growth Factor I,Insulin-Like Somatomedin Peptide I,Insulin Like Somatomedin Peptide I
D007335	Insulin-Like Growth Factor II	A well-characterized neutral peptide believed to be secreted by the LIVER and to circulate in the BLOOD. It has growth-regulating, insulin-like and mitogenic activities. The growth factor has a major, but not absolute, dependence on SOMATOTROPIN. It is believed to be a major fetal growth factor in contrast to INSULIN-LIKE GROWTH FACTOR I, which is a major growth factor in adults.	IGF-II,Multiplication-Stimulating Activity,Somatomedin MSA,IGF-2,Insulin Like Growth Factor II,Insulin-Like Somatomedin Peptide II,Multiplication-Stimulating Factor,Somatomedin A,Factor, Multiplication-Stimulating,Insulin Like Somatomedin Peptide II,Multiplication Stimulating Activity,Multiplication Stimulating Factor
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000824	Animal Nutritional Physiological Phenomena	Nutritional physiology of animals.	Animal Nutrition Physiology,Animal Nutritional Physiology Phenomena,Animal Nutritional Physiological Phenomenon,Animal Nutritional Physiology,Animal Nutritional Physiology Phenomenon,Veterinary Nutritional Physiology,Nutrition Physiologies, Animal,Nutrition Physiology, Animal,Nutritional Physiology, Animal,Nutritional Physiology, Veterinary,Physiology, Animal Nutrition,Physiology, Animal Nutritional,Physiology, Veterinary Nutritional
D017451	Receptors, Somatomedin	Cell surface receptors that bind somatomedins and trigger intracellular changes which influence the behavior of cells. Studies have disclosed two types of receptors for this family of peptide hormones. The type I receptor is homologous to the insulin receptor and has tyrosine kinase activity. The type II receptor is identical to the mannose-6-phosphate receptor which is important in trafficking of lysosomal enzymes.	Receptors, Insulin-Like Growth Factors,Somatomedin Receptors,Insulin-Like Growth Factor Receptor,Insulin-Like Growth Factor Receptors,Somatomedin Receptor,Insulin Like Growth Factor Receptor,Insulin Like Growth Factor Receptors,Receptor, Somatomedin,Receptors, Insulin Like Growth Factors
D018969	Insulin-Like Growth Factor Binding Proteins	A family of soluble proteins that bind insulin-like growth factors and modulate their biological actions at the cellular level. (Int J Gynaecol Obstet 1992;39(1):3-9)	IGF Binding Protein,IGF-Binding Protein,IGF-Binding Proteins,IGFBP,Insulin-Like Growth Factor Binding Protein,Somatomedin-Binding Protein,Somatomedin-Binding Proteins,Binding Protein, IGF,IGF Binding Proteins,Insulin Like Growth Factor Binding Protein,Protein, IGF Binding,Protein, IGF-Binding,Protein, Somatomedin-Binding,Somatomedin Binding Protein,Somatomedin Binding Proteins