Biochemical changes in the body fluids after lschaemic tissue injury.

Lymphatic and tissue fluid LDH activity increases significantly after 2 hr limb ischaemia but LDH content in tissue fluid invariably higher than in lymph. The differences increase further after 4 hr ischaemia. The change of GOT concentration in the body fluids is a less sensitive indicator of tissue damage than the increase of LDH activity. A 2 or 4 hour ischaemia does not lead to rupture of lysosomes and to a marked activity increase of the lysosomal enzymes acid phosphatase and beta glucuronidase in tissue fluid and lymph. The earliest biochemical signs of cellular injury can be detected in the interstitial fluid of the damaged tissue.