Urinary LDH isoenzyme 5 excretion in experimental pyelonephritis.

Studies to determine the effect of kidney parenchymal infection upon urinary lactic dehydrogenase (ULDH) isoenzyme composition were performed in 12 female Sprague-Dawley rats on Day 0 and on Days 2, 5, and 10, after experimental inducement of Escherichia coli pyelonephritis. An additional group of 12 animals was subjected to similar experimental manipulations and served as sham controls. Repeated 12-h urine collections revealed lower urine osmolalities and significantly higher levels of ULDH 5 excretion in the experimental than in the sham operated animals (P less than 0-05). These differences persisted for the length of the experiment (10 days). Leucocyte excretion rates were also higher in the experimental than in the sham group, and a high correlation with ULDH 5 activity was demonstrated (r = 0-815). No other evidence that the two variables may be causally related was found.