Lysosomal Hydrolases in Neutrophils, Mononuclear Cells and Serum during Escherichia coli Endotoxinaemia in Pigs

Abstract

The appearance of 10 different lysosomal enzymes in leucocytes and serum were studied during various stages of Escherichia coli endotoxinaemia in pigs. The animals were monitored in halothane anaesthesia and ventilated with a mechanical ventilator. The endotoxin infusion induced a marked increase in pulmonary artery pressure while the systemic blood pressure was significantly lowered. A pronounced decline in circulating leucocytes occurred. There was a general trend of intracellular reduction of lysosomal enzymes in both PMN and mononuclear cells, whereas increasing serum levels of the same enzymes occurred. Significantly higher serum levels of all lysosomal enzymes were found 5 h after start of endotoxin infusion compared to preinfusion values, while a significant acidosis in the aorta blood was registered. These results indicate that lysosomal enzymes are released from white blood cells following endotoxin stimulation. When local pH values allow enzyme activity, they may contribute to the tissue destruction seen in endotoxinaemia.