Immunoglobulins of the Hamster: II. Characterization of the γA and Other Immunoglobulins in Serum and Secretions¹ Free

An investigation of the distribution of immunoglobulins in the external secretions of the hamster revealed the predominance of γA. Only γA was found in saliva, whereas colostrum and urine both contained γ2 in addition to γA. Hamster γA was present in the serum at concentrations that were insufficient to allow its visualization by routine immunoelectrophoresis. No differences in electrophoretic mobility were found between serum and secretory γA regardless of derivation. The secretory γA from saliva, colostrum and urine had sedimentation characteristics intermediate between serum γA and 19S markers in sucrose density gradient ultracentrifugation studies. Similar results were obtained on Sephadex G-200 gel filtration. Isolated secretory γA had an s⁰_20,w of 15.2S. Mild reductive procedures did not appear to alter the sedimentation characteristics of this molecule. No antigenic differences were found between serum, salivary, colostral and urinary γA.