Effect of external lymph drainage and of coumarin treatment on thermal injury in the rat hind leg

Abstract

1. External lymph drainage brings about a significant protective effect in thermal oedema of the rat hind leg. It is suggested that external lymph drainage prevents vasoactive substances drained from the site of injury from passing into the blood stream, which would further increase permeability of the injured blood capillaries.2. Coumarin (5,6-benzo-alpha-pyron) brings about a significant protective effect against the same injury in sham-operated rats.3. The strongest protective effect may be attained by combining external lymph drainage with the administration of coumarin.4. The additional therapeutic effect brought about by coumarin treatment in rats with external lymph drainage is not mediated by an increased flow. The possible mechanisms are discussed.