Biomaterial Database

Role of the insulin-like growth factors and their binding proteins in lactation. 1998

W S Cohick

Department of Animal Sciences, Rutgers University, New Brunswick, NJ 08901-8525, USA.

Insulin-like growth factor (IGF)-I is thought to mediate a portion of the effects of bST on lactation in dairy cows. Serum concentrations of IGF-I are increased in lactating cows that were treated with bST, and IGF-I receptors are present in bovine mammary tissue. In addition, close arterial infusion of IGF-I into the mammary gland of goats increases milk yield. Little evidence exists to support a direct galactopoietic effect of IGF-I in ruminants. However, IGF-I is a potent mitogen for mammary epithelial cells and may also influence the inhibition of apoptosis of this cell type. The IGF are found in association with a family of individual binding proteins. The high affinity of the IGF for these proteins relative to the IGF receptor allows them to modulate IGF-I bioactivity in the mammary gland at the cellular level. Mammary epithelial cells synthesize multiple forms of IGF binding proteins, and one of these, IGF binding protein-3, is specifically regulated by the IGF. Stimulation of DNA synthesis by IGF-I is enhanced in bovine mammary epithelial cells that overexpress the IGF binding protein-3. These data indicate that IGF-I can stimulate the synthesis of an IGF binding protein, which enhances its own mitogenic activity. However, whether this mechanism is operative in the lactating mammary gland in vivo is unknown. Given the complexity of the interactions between the IGF and their binding proteins, more information is needed before the role of these growth factors in regulating growth, differentiation, and apoptosis of mammary epithelial cells is delineated.

UI	MeSH Term	Description	Entries
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
D007774	Lactation	The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.	Lactation, Prolonged,Milk Secretion,Lactations, Prolonged,Milk Secretions,Prolonged Lactation,Prolonged Lactations
D008321	Mammary Glands, Animal	MAMMARY GLANDS in the non-human MAMMALS.	Mammae,Udder,Animal Mammary Glands,Animal Mammary Gland,Mammary Gland, Animal,Udders
D009752	Nutritional Status	State of the body in relation to the consumption and utilization of nutrients.	Nutrition Status,Status, Nutrition,Status, Nutritional
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D005260	Female		Females
D006706	Homeostasis	The processes whereby the internal environment of an organism tends to remain balanced and stable.	Autoregulation
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
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