Tissue Culture Method for Bovine Mammary Tissue: Lactose Synthesis

An in vitro method for investigating lactose synthesis in bovine mammary tissue is described. Tissue bits were incubated in an oxygen-enriched Medium 199 supplemented with bovine serum, antibiotics, hydroxycortisone acetate, prolactin, insulin, and U-14C-glucose or U-14C-galactose for 2, 12, 24, and 36h. The tissue and medium were extracted separately with chloroform:methanol and radioactive components were identified. The mean percent recovery of radioactivity was 87 and 75% in the glucose and galactose experiments. After 36h, 37 and 18% of the total radioactivity recovered was in lactose synthesized from glucose and galactose. This method incorporates the advantages of the cell culture and tissue slice methods.