Quantitation of lysozyme in the urine of the dog for the diagnosis of proximal tubular damage in renal disease.

The serum and urine LZM levels were determined with the lysoplate assay in 26 normal experimental dogs and in 21 dogs with various renal diseases. In the dogs with decreased glomerular filtration the serum LZM levels were higher than in normal dogs (less than or equal to 1.3 mg/l). No LZM could be demonstrated in the urine of normal dogs. The presence of LZM in urine was associated with proximal tubular damage, which indicates that LZM-uria can be used as an index of renal tubular damage.