Untersuchungen zum Verhalten von Enzymen im Serum und Urin bei Nephrolithiasis

Abstract

Serum values and urinary rates of several enzymes (lactic-acid dehydrogenase, leucine aminopeptidase, malic dehydrogenase, α-amylase) were investigated in groups of patients characterized by clinical and biochemical features, as well as in healthy volunteers before and after i.v. infusion of calcium gluconate (type Kyle). Urinary LDH excretion in patients with hypercalciuric symptoms (oxalate stones) were significantly increased and primary hyperparathyroidism was refractory to otherwise calcium-induced changes of α-amylase in serum, permitting differential diagnosis. Stones resulting from urinary-tract infection evoked elevated LAP values in serum; urinary malic dehydrogenase in all patients was higher, compared to volunteers. The results of this study suggest that stone formation in human kidney is accompanied by elementary metabolic changes, possibly not respected enough as to their validity in the as yet unknown etiology of this disorder.