Comparative mitogenic and galactopoietic effects of IGF-I, IGF-II and Des-3-IGF-I in bovine mammary gland in vitro.
Insulin-like growth factors (IGFs) I and II (IGF-I, IGF-II) and Des-3-IGF-I at physiological concentrations are potent mitogens of bovine undifferentiated mammary epithelial cells cultured in collagen in a serum-free medium. Des-3-IGF-I was found to be as potent as IGF-I, while IGF-II was significantly less active. All three factors acted either synergistically or additively with epidermal growth factor (EGF), cholera toxin and fetal calf serum (FCS). Indirect evidence indicates that despite its lower mitogenic activity the action of IGF-II is mediated through IGF-I receptors. The galactopoietic activity of Des-3-IGF-I and IGF-II was studied in an organ culture of bovine lactating mammary glands using lactogen-responsive fat synthesis as a test. Neither Des-3-IGF-I nor IGF-II exhibited galactopoietic activity nor did they affect the galactopoietic activity of prolactin.
Peri
I
I
Department of Biochemistry and Human Nutrition, Faculty of Agriculture, Hebrew University, Jerusalem, Rehovot, Israel.
Shamay
A
A
McGrath
M F
MF
Collier
R J
RJ
Gertler
A
A
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis*; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D007774:Lactation; D008055:Lipids / Q000096:biosynthesis*; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009924:Organ Culture Techniques; D010446:Peptide Fragments / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology; D013002:Somatomedins / Q000494:pharmacology*
D008055:Lipids; D010446:Peptide Fragments; D013002:Somatomedins; C058957:insulin-like growth factor 1, des-(1-3)-; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011388:Prolactin; D004247:DNA; D002772:Cholera Toxin