INHIBITION OF LACTOGENIC ACTIVITIES OF BOVINE MAMMARY-GLAND EXPLANTS BY THE WHEY FRACTION OF BOVINE-MILK

The regulation of milk constituents, synthesis and secretion in tissue cultures of the bovine mammary gland was altered by a whey fraction o f bovine milk, alpha-Casein gene expression, casein secretion and fatt y acid synthesis were inhibited by the whey fraction in a dose-depende nt manner. The whey fraction inhibited the enhancement activity of pro lactin on alpha-casein gene expression and fatty acid synthesis, and a lso inhibited casein secretion to the medium, in explants cultured in a medium with or without prolactin. No effect on the expression of the beta-lactoglobulin gene was found. (C) 1997 Academic Press Limited.