title: Effects of a protein-free diet on the changes in cyclic AMP and cyclic GMP levels induced by immunization in splenic T and B lymphocytes in the rat.
abstract: The levels of cyclic nucleotides, cAMP and cGMP, were determined in splenic lymphocytes of normally fed (N) and protein deprived (PD) rats before and at different time intervals after a single injection of sheep erythrocytes. Assays were performed with protein binding methods on unseparated as well as on T and B cells fractionated by filtration through nylon wool. The cAMP levels increased in unfractionated cells and in T and B lymphocytes 2 hours following immunization of N rats. Another rise in cAMP levels occurred after 3 days in B lymphocytes, but there was also a simultaneous increase of the cGMP levels in preparations of unfractionated cells and in B lymphocytes. The PD diet suppressed or delayed most of the aforementioned changes. Thus, the immunodepressive effect of such a diet may be ascribed to the inhibition of both the early signal (increase of cAMP levels and of cAMP/cGMP ratio) leading to T and B differentiation and the later signal (increase of cGMP levels) which initiates antibody production.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D001835:Body Weight; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D004044:Dietary Proteins; D004912:Erythrocytes / Q000276:immunology; D007114:Immunization; D007700:Kinetics; D008297:Male; D051381:Rats; D013154:Spleen / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
chemical_list: D004044:Dietary Proteins; D000242:Cyclic AMP; D006152:Cyclic GMP