BIOLOGICAL PROPERTIES OF GOAT IMMUNOGLOBULINS-G

  • 1 January 1977
    • journal article
    • research article
    • Vol. 32  (4) , 373-381
Abstract
The serum concentration of normal adult goat total Ig[immunoglobulin]G was 19.97 .+-. 1.55 mg/ml, the IgG1 was 10.92 .+-. 0.84 mg/ml and IgG2 was 9.07 .+-. 0.78 mg/ml. No significant variations were associated with the seasons of the year but changes in concentration, especially in serum IgG1 occur ante- and post-partum. In goat colostrum the IgG concentration is about 2.4-2.8 times greater than in serum and the IgG1 subclass accounts for 95-98%. During the immune response the IgG1 rises sharply whereas variations in IgG2 concentration are less evident. Both IgG subclasses are active in hemagglutination, although the IgG1 is 22-52 times more efficient. As in all ruminants, only IgG1 fixes complement in the classical test. Differences exist between IgG subclasses in their ability to induce PCA [passive cutaneous anaphylaxis] reactions. IgG2 subclass is active only in homologous species whereas the IgG1 in heterologous species [e.g., guinea pigs]. Cytophilic activity is associated with IgG2 subclass.