Changes in the composition of rabbit hind limb lymph after thermal injury.

1. Lymph was collected directly from the hind limbs of rabbits anaesthetized with pentobarbitone and from unanaesthetized rabbits before and for several days after the hind limb was injured.2. After the limb was injured with hot water at 60 degrees C for 1 min or at 80 degrees C for 15-20 sec, there was an increase in the concentration of cytoplasmic and mitochondrial enzymes in the lymph.3. As previously found in cats, it was not until cell destruction was brought about by freezing the limb solid, that there was an increase in the concentration of lysosomal enzymes in the lymph.4. In rabbits which had a cannula permanently implanted in the femoral lymphatic, it was found that the elevated enzyme levels following a 60 degrees C burn returned to normal at between 24 and 36 hr after injury.5. The increase in enzyme activities usually occurred in two phases, an initial increase during the first 4-6 hr after the burn followed by a second increase which reached a maximum between 10 and 16 hr after injury.6. Even during the second phase which corresponded with the cellular phase of injury there was no increase in lysosomal enzymes.7. The present results support the earlier conclusion that lysosomes take little or no part in the tissue reaction to thermal injury except in the later scavenging processes after cell break-down.