Enzymuria as a marker of bladder damage in acute urinary retention

In experiment on 20 rats we studied the effect of a 4-hour acute urinary retention (AUR) on the functional state of the bladder and the change in activity of some enzymes (AST and ALT transaminases, lactate dehydrogenase -LDH, alkaline phosphatase - ALP, y-glutamyltranspeptidase-GGTP, N-acetyl -ß-glycosidase - NAG and cholinesterase - CE) in the urine and the bladder wall, comparing them with the changes after 2-hour total ischemia of the bladder caused by pelvic clamping of the aorta. Along with the deterioration of functional parameters we registered significant increase of activity of all studied enzymes in the experiments with AUR, mostly cytoplasmic enzymes (AST, ALT, LDH). In the experiments with ischemia also increase in activity of cytoplasmic enzymes in the urine was registered, whereas the activity of membrane enzymes increased insignificantly. In the bladder wall after AUR as well as after ischemia the activity of all enzymes decreased significantly, except for CE in the experiments with ischemia. Renal function, assessed by creatinine clearance and sodium reabsorption, in all the experiments were not significantly different from the normal values. Reduced enzymatic activity of the bladder wall and the lack of data for renal tubular damage suggests that the source of increased enzymuria after AUR is a damaged wall of the bladder. The similarity of changes in enzyme activity in experiments with AUR and ischemia may indicate an important role of ischemic damage factor of the bladder in AUR.