Objectives: Urinary loss of tubular marker enzymes following shock wav
e lithotripsy (SWL) suggests corresponding morphological changes in th
e kidney. To date, the morphological correlate of enzymuria and its de
pendence on the energy applied remains unclear. Methods: In an animal
study, the acute morphological changes occurring in the tubulus cells
as the basis of enzymuria were investigated. It was evaluated whether
SWL-induced enzymuria correlates with the extent of renal damage. Resu
lts: Acute morphological changes in the tubulus cells were demonstrate
d beneath isolated tubulus necrosis. The mechanically induced lesions
of the cell organelles included fragmentation of the lysosomes and sev
ere alterations of the cell membrane. The tubulus damage can be quanti
fied. With the help of histochemical N-acetyl-beta-D-glucosaminidase (
NAG) staining and electron microscopic observations, a significant cor
relation was found between the shock wave parameters number of impulse
s and intensity and the tubular damage. The intensity of NAG enzymuria
reflected the severity of the tubular damage. Conclusions: In this an
imal model, NAG proved to be a suitable marker enzyme for estimation o
f the degree of SWL-induced tubular damage.