Changes in the cAMP level in macrophages during the phagocytosis of Salmonella typhimurium. II. Effect of the virulence of microorganisms and the immune status of the macrophages on the dynamics of changes in cAMP levels

The dynamics of changes in the level of intracellular cyclic AMP in nonimmune and immune macrophages in the process of the phagocytosis of S. typhimurium virulent strain, its heated variant and its mutant with low virulence was studied. A transient increase in the level of cyclic AMP was shown to occur during the first 30 minutes of phagocytosis; this increase did not depend on the kind of the phagocytized object and on the activity of macrophages and neither had it any influence on the outcome of phagocytosis. The virulent strain also induced the three-fold increase of the level of cyclic AMP in nonimmune macrophages prior to their disintegration caused by the cytopathogenic action of the microorganism. In immune macrophages the virulent strain did not induce the secondary increase of the level of cyclic AMP.