The effect of anti-inflammatory agents on the changes in local lymph after thermal injury

1. Lymph was collected directly from the hind limbs of rabbits anaesthetized with pentobarbitone and from unanaesthetized rabbits before and after one hind limb was injured by immersion in water at 60 degrees C for 1 minute.2. Rabbits were treated with anti-inflammatory agents hydrocortisone or indomethacin which, in acute experiments, were infused close-arterially into the limb either at the time of the injury or 90 min later. In chronic experiments hydrocortisone was given intravenously three times a day.3. When given at the time of the injury both drugs reduced the subsequent mean increases in the lymph of the intracellular enzymes lactate dehydrogenase and glutamic pyruvate transaminase but not those of beta-glucuronidase and protein; whereas when given 90 min after the injury only the increase in lymph protein concentration was reduced.4. The results indicate that these anti-inflammatory agents probably inhibit the second phase of increase in vascular permeability which occurs after injury and in addition, reduce the leakage of intracellular protein by a non-specific effect on membrane permeability.5. The pronounced variability of the response of individual animals and the complexity of the experiments preclude the method as a suitable model for the estimation of anti-inflammatory activity.