| Description |
Experiments were performed to assess whether changes in the intracellular concentrations of cyclic 3', 5' adenosine monophosphate (cAMP) and cyclic 3', 5' guanosine monophosphate (cGMP) could be: (1) associated with alterations in macrophage function; and (2) related temporally to lysoosomal enzyme release and glucosamine incorporation during macrophage activation. The macrophage enriched cell populations utilized for these experiments were murine macrophages from the continuous cell line J774.1, and rabbit alveolar macrophages (AM). Three cAMP experiments were run using J774.1 macrophages stimulated in vitro. In two of these experiments, the cells were incubated in the presence of lipoplysaccharide (LPS), and in the third experiment, with BCG cell wall material. Also, lysosomal enzyme levels (i.e., beta-glucuronidase and lysosyme) were measured using AM from BCG-infected rabbits. Other experiments were set up to determine the following: (1) the cAMP an cGMP resting levels of AM and J774.1 macrophages; and (2) the cAMP and cGMP levels of J774.1 macrophages when stimulated with methyl isobutyl xanthine (MIX). Evidence that J774.1 macrophages can be activated when using the same stimulant concentrations and incubation conditions used in the experiments described has been reported. There has been no observed change in teh cAMP levels of J774.1 macrophages stimulated under these conditions. Furthermore, due to the high medium blanks, cGMP was not able to be measured in most of the experiments. In conclusion, it has not yet been possible to demonstrate a role for either cAMP or cGMP as mediators in the process of macrophage activation. |
