Effect of bovine growth hormone on development of goat mammary tissue in organ culture.

The effect of bovine growth hormone (bGH) on DNA, protein and casein synthesis in goat mammary explants was studied. Growth hormone was unable to stimulate DNA synthesis or potentiate insulin-stimulated DNA synthesis either in high or low oxygen concentrations. In the presence of insulin and cortisol bGH had no effect on the synthesis of explant cytosol proteins. Two preparations of bGH were tested for their effect on casein synthesis. The preparation NIH-GH-B17 at concentration 50 micrograms ml-1 increased casein synthesis similarly as about 0.5 micrograms ml-1 of prolactin. Our preparation, prepared by the method of Prusík and Braun [1967], at concentration 50 micrograms ml-1 had effect lower than 0.05 micrograms ml-1 of prolactin. The lactogenic activity of NIH-GH-B17 was decreased by treatment with specific antisera to bovine prolactin. When submaximum concentration of prolactin (0.05 microgram ml-1) was added, bGH at concentration as low as 0.5 microgram ml-1 had synergistic effect on prolactin stimulated casein synthesis.