The influence of various benzo-pyrones on acid and neutral protease activity levels, the cells from which they may arise and their importance in the resolution of lymphoedema.

The availability of digestable material to a phagocyte determines not only the rapidity and completeness of digestion but the amount of lysosomal enzyme which reaches the extracellular compartment and the circulation. The measurement of enzyme activities in thermally injured limbs has shown the benzo-pyrones to enhance acid protease activity. There is much evidence to suggest this activity originates from macrophages which enter the thermally injured regions in great numbers. In this paper the administration of benzo-pyrones to animals with lymphoedema is reported to enhance neutral protease activity levels. This activity is not associated with mononuclear cells but with the neutrophils. Although additional histological work must be done to confirm the presence of neutrophils in lymphoedematous tissues there is evidence to suggest the increases in neutral protease levels arise from neutrophils and that in lymphoedema it is these cells which are acted upon by the benzo-pyrones. They then cause the removal of protein by enhancing its lysis either within the cells or in the extracellular compartment.