Rat immunoglobulins in serum and secretions: comparison of IgM, IgA and IgG in serum, colostrum, milk and saliva of protein malnourished and normal rats.

Immunoglobulin levels in colostrum and milk of normal and protein malnourished rat dams and in serum and saliva of their offspring were quantitated by radial immunodiffusion employing purified anti-rat alpha, gamma and mu. In general, no significant difference was observed in the level of colostral IgA in malnourished as compared to normal rat dams or in the level of serum IgA and IgM and salivary IgA and IgG2a of their offspring. On the other hand, malnourished mothers demonstrated approximately twofold lower levels of colostral IgG2a than normal mothers throughout the entire period of lactation. In addition, at every interval tested, the level of IgG was approximately 1.5- to 2-fold less in malnourished as compared to normal offspring.