Further studies on the diagnostic value of γ-glutamyl transpeptidase and 5′-nucleotidase in cattle, sheep and horses

The distribution of 5′-nucleotidase (5′-nt) and γ-glutamyl transpeptidase (γ-gt) is similar in the tissues of the sheep, calf and horse, except that there is relatively less γ-gt in calf liver than in the liver of the other two species. The liver lesion produced by the oral administration of chloroform is similar in the three species and is accompanied by the release of 5′-nt into the plasma of the sheep and calf but not of the horse. Conversely, γ-gt is released into plasma of the horse but not of the sheep or calf. This difference is not related to the tissue distribution of the two enzymes. The kidney lesion in sheep produced by the intravenous administration of mercuric chloride is accompanied by a reduction in the rate of excretion of an injected dose of inulin and by an increase in the concentration of urea in plasma and in the activity of γ-gt in plasma and urine. There was no increase in 5′-nt activity in plasma or urine.