| Abstract: | The binding of 3H-corticosterone by rat alveolar macrophages was studied before and after stimulation with zymosan in vivo. Thirty min after incubation of the macrophagal monolayer from intact animals with 3H-corticosterone accumulation of the hormone by the cells came to an end. As the concentration of 3H-corticosterone in the incubation medium was raised, the binding of the hormone with the saturated (receptor) system of alveolar macrophages terminated upon absorption of 10.6 fmol per 10(6) cells. Further raising of the level of the bound hormone was effected by the unsaturated (lipid) system. Stimulation with zymosan led not only to an increase in the number of the cells of the bronchoalveolar tract but also to an elevation of the intensity of 3H-corticosterone engulfment by alveolar macrophages. The number of binding sites per cell in the zymosan-activated macrophages increased 1.5-fold. This may be an important moment determining the development and liquidation of mononuclear infiltrations in the lung. |
