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THE MECHANISM OF TRANSFER OF IMMUNOGLOBULIN INTO MAMMARY SECRETION OF COWS
Author(s) -
Brandon MR,
Watson DL,
Lascelles AK
Publication year - 1971
Publication title -
australian journal of experimental biology and medical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0004-945X
DOI - 10.1038/icb.1971.67
Subject(s) - endocrinology , medicine , albumin , immunoglobulin g , secretion , antibody , chemistry , bovine serum albumin , immunoglobulin m , serum albumin , serum concentration , biology , immunology , biochemistry
Summary Changes in the concentration of IgG 1 , IgG 2 , IgM, IgA and albumin in serum and mammary secretion were studied in 15 cows and 2 heifers before and after parturition. Concentrations of IgG 1 and IgG 2 in blood serum 3–5 weeks before parturition were 13·38 ± 0·75 and 10·08 ± 0·39 mg/ml (means ± S.E.) respectively. In all animals the concentration of IgG 1 in serum decreased abruptly, usually by more than 50%, 2·3 weeks before parturition, and during the same period the concentrations of IgG 2 , IgM, IgA and albumin in serum remained unchanged. Four weeks after parturition the concentration of IgG 1 in serum had returned to values similar to those observed prior to the abrupt fall. Five weeks before parturition the concentration of IgG 1 in mammary secretion was, on average 11 times higher than that of IgG 2 . Highest concentrations of IgG 1 in secretion (113·89 ± 11·41 mg/ml) were observed 2–3 weeks before parturition in 16 of the 17 animals. The concentration of IgG 2 over the 5 weeks prior to parturition remained unchanged at levels of approx 30% of comparable values in serum. Concentrations of IgM (11·85 ± 0·53) and IgA (3·80 ± 0·20) in secretion collected prior to and immediately after parturition were, on average, 2 and 7 times higher respectively than those in serum. The sharp fall in the concentration of IgG 1 in serum in the absence of any suggestion of a concomitant decrease in IgG 2 concentration strongly suggests that the degradation hypothesis proposed by Brambell (1958, 1966) for selective transfer of protein across epithelial membranes does not hold for the mammary gland of the cow. The results support an alternative hypothesis based on the existence of IgG 1 ‐specific receptor sites located on the basal or intercellular membrane of the glandular epithelial cells.