Effect on rat IgA synthesis by isotypic suppression with an anti-rat delta heavy chain serum.

It is highly probable that IgA precursor cells have IgD receptors during their ontogeny, however isotypic suppression with anti-delta serum did not demonstrate this possibility at least in our experimental conditions. Moreover, isotypic suppression with anti-delta serum seems ineffective in diminishing the serum levels of Ig classes other than IgD under these conditions, as IgM, IgE and IgG serum levels were relatively unaffected, at least during the first month of the rat life.