A lack of coordination in the release of urinary lysosomal and brush border enzymes following renovascular surgery.

The urinary secretion of two lysosomal enzymes, N-acetyl-D-glucosaminidase (NAG, EC 3.2.1.30) and beta-glucuronidase (GLR, EC 3.2.1.31), and two brush border enzymes, alanine aminopeptidase (AAP, EC 3.4.11.2) and gamma-glutamyltransferase (GGT, EC 2.3.2.2), was examined in apparently healthy individuals and in patients before and after renovascular surgery for treatment of hypertension. Eight out of nine patients had elevated levels of at least one enzyme before surgery. The ranking in their frequency of elevation was NAG greater than AAP greater than GLR greater than GGT. In comparing the release of any two enzymes in apparently healthy individuals, the release was coordinated except for GGT and GLR. In individual patients following surgery the excretion of the lysosomal enzymes was highly coordinated whereas the release of the brush border enzymes was less coordinated. Comparisons of lysosomal to brush border enzyme activities revealed dissimilar release patterns between these two classes of enzymes. Analysis of variance over the entire hospitalization period showed that NAG/GLR (p = 0.42) and AAP/GGT (p = 0.12) did not vary significantly whereas all comparisons of lysosomal to brush border enzymes varied significantly (p less than or equal to 0.03). These results indicate that enzymes derived from different subcellular organelles, lysosomes or brush borders, have similar release patterns. However, the lack of a significant correlation between lysosomal and brush border enzyme excretion implies that the two processes are not interdependent. These studies further suggest that the transient pathophysiological changes that occur within renal cells following renovascular surgery affect these cellular components in different ways.

Duke Scholars

Author Dean George Assimos Urology