STUDIES ON γ-GLUTAMYLTRANSPEPTIDASE IN WARM ISCHAEMIC KIDNEYS OF RATS

Abstract

The effect of warm ischaemia on γ-glutamyltranspeptidase [EC2.3.2.2.] (γ-GTP) activity was studied in the rat kidney.
A circadian rhythm for the urinary excretion of γ-GTP is demonstrated. Furthermore, it is demonstrated that urinary γ-GTP activity correlates with renal ischaemia. Of the ischaemic durations studied, urinary enzyme activity was greatest after 30 minute ischaemia. However, slight or no increase of the enzyme activity was seen after 5 or 60 minute ischaemia.
Enzyme activity was appreciably greater in the urinary pellet than in the soluble fraction after ischaemia, suggesting that the enzyme may be contained in the brush border of the proximal tubules sloughed into the urine.
An initially decreased enzyme activity in the kidney returned to normal at 7 days after 60 minute ischaemia, but such enzymic recovery was not observed after 120 minute ischaemia, suggesting that viability of the kidney may be estimated from renal γ-GTP activity.