Comparison of morphological and biochemical changes of BAL-isolated cells in experimental lung emphysema

The aim of the study was to evaluate the protease and antiprotease activity in the fluid obtained from the culture of cells isolated from the lungs of animals with experimental emphysema. An attempt was made to correlate the results of biochemical examinations with adherence degree and ultrastructural changes of the surface of BAL-isolated cells. The experiment was carried out on male Wistar rats, of 180-220 g b.w. Two i.p. injections of BCG-vaccine (4 x 10(8) microorganisms) on the 1st and 14th day were applied as macrophage mobilizing and activating agent. Papain (2 mg/l ml/100 g b.w.) was given once i.t. on the 21st day. The animals were sacrificed on the 28th day of the experiment. We found a correlation between the increase in the cell adherence and ultrastructural changes (in SEM), suggesting an increased activity of the cells isolated from BCG-treated rats. In the culture medium of cells isolated from the rats which were given BCG or papain and BCG+papain we observed an increased base protease activity and decreased Cathepsin D activity comparing with the control group. Increased antitrypsin activity in the BCG and BCG+papain-treated rats and decreased antitrypsin activity in papain-treated rats only was observed, too. There was no obvious difference in the levels of the antiplasmin and antichymotrypsin activities between the groups. The present results indicate that activated pulmonary macrophages are one of the sources of the protease-antiprotease intraalveolar imbalance. However, an increased production of proteolytic enzymes may not be the only factor responsible for the progression of lung emphysema in BCG-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)