[Immunomodulating action of ceruloplasmin in tumor growth and the participation of cyclic nucleotides].

The study was concerned with the effect of human ceruloplasmin on blastogenic reaction of lymphocytes (BRL) and cyclic nucleotide level in murine organs in the course of Lewis lung carcinoma development. Both ceruloplasmin and an immunomodulator--zymosan--were found to raise the level of cAMP and to lower that of cGMP in the immunocompetent organs (thymus and spleen) of tumor-bearing mice at all stages of the investigation. The results point to an immunomodulating action of human ceruloplasmin involved in tumor growth and the role played by cyclic nucleotides in the process.