Anaphylactic Antibody in the Young Rat

Abstract

Young rats, 2 to 3 weeks of age, produced serum concentrations of anaphylactic antibody comparable to those found in the sera of adult animals. In contrast, the production of total precipitating antibody was much lower in young rats. Passage of anaphylactic antibody from the maternal to the fetal circulation could not be detected with the method employed. Transmission of anaphylactic antibody to the suckling babies was readily accomplished in the 1st 2 weeks of life, indicating that this type of immunoglobulin is present in high concentration in the milk and is easily absorbed from the intestinal tract of the babies. Newborn rats could not be passively sensitized with rat anaphylactic antibody. The ability to become passively sensitized was gradually established with progressing age.