Serum and secretory immunoglobulin levels in preleukaemic AKR mice and three other mouse strains.

Levels of IgM, IgC1, IgG2 AND IgA were determined in serum and milk of AKR mice, which spontaneously develop lymphoma at 6--14 months of age. As a reference C3H, CBA and C57BL mice were studied. Of the four mouse strains studied AKR had the lowest serum and secretory IgA levels. The values of the other immunoglobulins in AKR mice were comparable to those of CBA mice. C3H and C57BL mice had significantly higher immunoglobulin levels. Serum of lactating mice showed fairly decreased IgG1 and IgG2 levels as compared with non-lactating mice, probably due to transudation into the milk. The serum IgM and IgA levels were not consistently affected by lactation.