The activity of gamma glutamyltransferase in the urine of sheep
Van dn Berg, J.S.
Journal of the South African Veterinary Association 61(2): 46-49
1990
ISSN/ISBN: 1019-9128 PMID: 1981081 Document Number: 364244
The activity of gamma glutamyltransferase (GGT) was measured in sheep urine using a method developed for the routine assay of serum. Despite variation in urine pH and specific gravity, this method gave reproducible results. Serial dilutions of urine samples to which bovine GGT extract was added, showed a linear relationship for GGT values between 48 U l-1 and 373 U l-1. When a saline solution of GGT was added to urine and serum to compare the behaviour of GGT in the two fluid mediums, no difference could be demonstrated. The presence of non-specific enzyme inhibitors for GGT in sheep urine could not be established, eliminating the need for urine dialysis before the assessment of GGT activity. GGT activity remained the same in urine samples that were stored at 4, 25 and -20 degrees C for 12 and 24 hours. Serial urine samples from 16 sheep were collected for 24 hours and the activity of GGT and the creatinine concentration were measured. Although there was significant variation in the measured GGT and creatinine values, the ratio of GGT:creatinine remained constant. The mean urine GGT:creatinine ratio was found to be 29.1 with a standard deviation of 7.0. A population reference value for urine GGT: urine creatinine ratio in clinically normal sheep was calculated to be 43.1.