Comparison of colony stimulating activities secreted into mouse lung conditioned medium in the presence and absence of lithium chloride.

Inclusion of lithium chloride during the process of secretion of granulocyte-macrophage colony stimulating activity (CSA) into mouse lung conditioned medium resulted in an increased production of CSA. CSA produced in the presence of lithium chloride was compared to the CSA produced in its absence by means of ammonium sulfate precipitation, Sephadex G-1CO (S) chromatography, concanavalin A-Sepharose chromatography and polyacrylamide gel electrophoresis. It was found that the two activities behaved identically, indicating that lithium-induced increase in CSA does not involve a qualitative change in the molecule of the colony stimulating factor, but reflects an increased production (or release) of a CSF molecule that is similar to the one produced in its absence.