[High sensitive photometric assay of pancreatic lipase and clinical investigation of urinary lipase in patients with various histopathological types of primary glomerulonephritis].

We measured the activity of urinary lipase by high sensitive photometric method using 1,2-dirinoleoilglycerol as a substrate. Also, we investigated the clinical significance of the activity of urinary lipase in patients with chronic glomerulonephritis (GN) with special reference to the relation between the levels of the enzyme and histopathological changes of the kidney. Urinary activity of N-acetyl-beta-D-glucosaminidase (NAG) and urinary beta 2-microglobulin (BMG) were also measured to compare the difference of renal handling of these 3 substances. We could obtain the following results; 1) Good coefficient of correlation was observed between the activity of urinary lipase and the excretion of urinary BMG. 2) No correlation was observed between the activity of urinary lipase and the amount of urinary NAG in patients with chronic GN. 3) In some of the cases with secondary tubulointerstitial edema and inflammatory infiltration, the values of the activity of urinary lipase were markedly elevated. These results suggested that lipase was removed from the serum mainly by glomerular filtration and reabsorbed almost completely by tubular epithelial cells like the renal handling of BMG. In contrast, NAG secreted through the different renal metabolism in proximal tubule. The activity of urinary lipase might be a diagnostic marker for the secondary acute tubulointerstitial lesions in patients with chronic GN.

[Clinical investigation of urinary activity of NAG and AAP in patients with various types of primary glomerulonephritis].

We investigated the activity of NAG and AAP in the urine of 36 patients with chronic glomerulonephritis (GN) with special reference to the relation between the levels of the enzymes and histopathological changes of the kidney. The subjects consist of 7 cases of minimal change nephrotic syndrome (MCNS), 3 cases of membranous GN, 5 cases of IgA. GN, 5 cases of membranoproliferative GN, 3 cases of focal glomerulosclerosis and 12 cases of chronic renal failure who had creatinine levels of more than 2 mg/dl resulting from chronic GN. Urinary levels of NAG and AAP were significantly higher in cases with GN than those in cases with chronic renal failure. In cases with GN, urinary levels of NAG and AAP correlated with the amounts of urinary protein, while those levels had no correlation with the classification of histopathological changes of glomeruli. The high value of NAG/mg.protein ratio, NAG by urinary protein, might be explained by the degree of tublointerstitial damage. We concluded that urinary levels of NAG and AAP reflects the proximal tubular damage caused by protein reabsorption.