[The regulatory role of pulmonary surfactant in macrophage metabolism].

The surfactant was isolated from rat lung tissue and its effect on biosynthesis of DNA, RNA and protein as well as content of cyclic nucleotides and prostaglandins was studied in macrophages. When the surfactant was incubated simultaneously with lung macrophages within 6 hrs, an initial inhibition and subsequent activation of DNA, RNA and protein synthesis were observed. Stimulation of protein synthesis was found to follow the increase in the biosynthesis of DNA and RNA. At the same time, the surfactant induced elevation of cAMP in the macrophages within 1 hr of cultivation, while content of cGMP was decreased within 3 and 6 hrs. Content of prostaglandins E was increased in the cells and concentration of prostaglandin F2 alpha was decreased within 6 hrs. The findings suggest that the surfactant-mediated increase of DNA-induced protein synthesis was cAMP-, cGMP- and prostaglandin-dependent.