Urinary trehalase as an early indicator of cadmium-induced renal tubular damage in rabbit.

The significance of urinary trehalase as a possible early indicator of renal disorder was examined using Cd-treated rabbits, which received 1 mg/kg Cd thrice weekly for 3 months subcutaneously. The results showed that urinary trehalase increased significantly from 1 week after treatment, earlier than LAP, ALP, proteinuria and glucosuria, with no changes in plasma trehalase level. A marked decrease in trehalase activity in renal brush border membranes prepared from Cd-treated rabbits was observed. It was also confirmed by immunohistological techniques that Cd treatment resulted in a marked decrease in specific fluorescence compared with controls. Ouchterlony double diffusion analysis demonstrated that urine and renal brush border extracts formed precipitation lines against anti-renal trehalase IgG, indicating that urinary trehalase and renal trehalase had the same antigenicity. Therefore, the facts presented here would suggest that urinary trehalase originated from the renal brush border, indicating its superiority as a diagnostic tool over other indicative indicating its superiority as a diagnostic tool over other indicative enzymes like LAP and ALP in detecting injury to renal proximal tubular cells in the early stage.