title: Transfer of protein antigens into milk after intravenous injection into lactating mice.
abstract: We investigated the transfer of bovine serum 125I-albumin (125I-BSA), bovine 125I-gamma-globulin (125I-BGG), 125I-ovalbumin (125I-OVA), and 125I-beta-lactoglobulin (125I-BLG) from the blood into the milk of lactating mice. Equal amounts (by weight) of the radiolabeled proteins were injected intravenously into mice 1 wk postpartum. Total radioactivity, trichloroacetic acid-precipitable radioactivity, and specifically immunoprecipitable radioactivity were measured in serum, mammary gland homogenate, and milk. Clearance of immunoreactive OVA (iOVA) and iBLG from the circulation was more rapid than iBSA and iBGG. The radioactivity in mammary tissue associated with BSA and BGG was greater than 70% immunoprecipitable throughout the 4-h test interval; 125I-OVA and 125I-BLG were less than 12% precipitable 1 and 4 h after injection. In milk obtained at 4 h, there was an approximately 10-fold greater accumulation of iBSA or iBGG than of iOVA or iBLG. These experiments demonstrate that protein antigens differ in their ability to transfer from maternal circulation into milk. The transfer into milk appeared to be in proportion to persistence of the antigens in the maternal circulation.
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology*; D004044:Dietary Proteins / Q000276:immunology / Q000378:metabolism; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology; D007457:Iodine Radioisotopes; D007774:Lactation; D007782:Lactoglobulins; D051379:Mice; D008892:Milk / Q000276:immunology*; D010047:Ovalbumin; D011247:Pregnancy; D012711:Serum Albumin, Radio-Iodinated; D005719:gamma-Globulins
chemical_list: D000941:Antigens; D004044:Dietary Proteins; D007457:Iodine Radioisotopes; D007782:Lactoglobulins; D012711:Serum Albumin, Radio-Iodinated; D005719:gamma-Globulins; D010047:Ovalbumin