Selective enhancement of the induction of alpha-lactalbumin activity in rat mammary explants by epidermal growth factor.
Epidermal growth factor (EGF) enhances the induction of alpha-lactalbumin in mammary explants from pregnant and virgin rats in the presence of insulin (I), hydrocortisone (F) and prolactin (P). EGF also enhances the prolactin-independent induction of alpha-lactalbumin in tissue from pregnant rats and evokes prolactin-independent induction of alpha-lactalbumin in mammary tissue from virgin rats in the presence of I and F. Casein synthesis and galactosyltransferase activity are unaffected by EGF in the IFP-system, and are not induced in the IF-EGF-system. Multiplication stimulating activity, nerve growth factor, fibroblast growth factor and platelet-derived growth factor do not mimic the selective effects of EGF on rat alpha-lactalbumin. These influences of EGF on the differentiation of isolated rat mammary tissue are compared with those on mouse and rabbit tissue studied previously.
D000818:Animals; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007768:Lactalbumin / Q000096:biosynthesis*; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D007328:Insulin; D004815:Epidermal Growth Factor; D011388:Prolactin; D007768:Lactalbumin; D006854:Hydrocortisone