Analysis of glycosuria in okapi (Okapia johnstoni): examination of urinary N-acetyl-β-D-glucosaminidase.

We analyzed the urinary excretion of glucose and N-acetyl-β-D-glucosaminidase (NAG) in six okapis (Okapia johnstoni) in captivity to investigate the cause of their urinary sugar excretion. The urinary glucose-positive okapi had significantly higher urinary NAG indices than the urinary glucose-negative okapi. There was also a positive correlation between urinary glucose levels and urinary NAG indices. These results suggest that the proximal tubular function of the glycosuric okapi may have been obstructed, which impaired glucose reabsorption.