Urinary N-acetyl-β-D-glucosaminidase Concentration and its Isozyme in a Diabetic Japanese Black Cow

Abstract

In a diabetic 4-year-old Japanese black cow, the urinary concentration of N-acetyl-β-D-glucosaminidase (NAG) and NAG index were 8.4U/l and 20.2U/g, respectively, being higher than in non-diabetic cows. The form B NAG isozyme was 66.6% in the present case, while 20% in non-diabetic cows. In the diabetic case, the renal function was lowered. Histopathological examination revealed granular degeneration of the proximal convoluted tube, hyaline degeneration of collecting duct and severe focal interstitial nephritis indicating that the increase of NAG isozyme B is due to the renal tubular and interstitial lesions.