Intracellular enzymes in serum, lymph and urine after renal ischaemia.

Urine, renal and thoracic duct lymph were collected in dogs before and after clamping both renal arteries. After 30 minutes of renal ischaemia there was a marked increase in concentration of cyto­ plasmic enzymes in renal lymph and urine. Less prominent rises also were observed in plasma and thoracic duct lymph. After 2 hours of ischaemia in addition to further increase in concentration of cytoplasmic enzymes a rise in activities of mitochondrial (GPT, ale. phosphatase, arylamidase) and lysosomal (acid phos­phatase) enzyines was observed in urine and renal lymph. In some animals a significant arterial-renal venous difference was found in LDH concentration, and in renal lymph the LDH isoenzyme pattern shifted towards more slowly migrating M subunits. There was marked parallelism between enzyme concentrations in renal lymph and urine. It is concluded, that determination of intracellular enzymes in renal lymph and urine affords a method to assess severity of ischaemic cell damage in the kidney.