Identification of alpha transforming growth factor as a possible local trophic agent for the mammary gland.
Biologically active alpha-transforming growth factor (alpha-TGF) has been identified in medium conditioned by rat mammary myoepithelial and, to a lesser extent, by epithelial cell lines in culture and in the rat mammary gland. The alpha-TGF has been identified by its wide spectrum of activity in promoting growth of mammary-derived cells in vitro, by its chromatographic behaviour on reversed-phase high-performance liquid chromatography (HPLC), by its competition with epidermal growth factor (EGF) for the EGF receptor, and by the presence of messenger RNA for alpha-TGF in the secreting cells. In vivo the amount of alpha-TGF isolated is sixfold greater from the mammary glands of lactating than from those of virgin female rats. It is proposed that alpha-TGF is produced by the myoepithelial cells of the mammary gland, as a local trophic agent that stimulates growth of the various cell types of the gland.
Smith
J A
JA
Department of Biochemistry, University of Liverpool, England.
Barraclough
R
R
Fernig
D G
DG
Rudland
P S
PS
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media / Q000032:analysis; D004847:Epithelial Cells; D004848:Epithelium / Q000032:analysis / Q000502:physiology; D005260:Female; D008321:Mammary Glands, Animal / Q000032:analysis / Q000166:cytology / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D015291:Transforming Growth Factors / Q000032:analysis / Q000235:genetics / Q000502:physiology*
D003470:Culture Media; D012333:RNA, Messenger; D015291:Transforming Growth Factors