Overview
- Membrane-associated enzyme.
- Highest levels in renal tubular epithelial cells, canalicular surfaces of hepatocytes and bile duct epithelium - also present in pancreas and small intestine.
- Hepatobiliary system is main source of serum GGT in health and disease.
Uses
In combination
- Cholestasis.
- Liver damage.
Result data
Normal (reference) values
US
- Example of reference interval: 1.2-6.9 u/l.
- Reference interval may vary with method/laboratory.
Abnormal values
Increased [GGT]
- Liver damage (especially chronic, eg cirrhosis
):
- Rise in GGT often lags 2-3 days behind ALT and ALT increases.
- Rise in GGT often lags 2-3 days behind ALT
- Cholestasis.
Errors and Artifacts
Drug induced increase
- Increase less dramatic than increase in ALP :
- Glucocorticoids.
- Phenytoin .
- Barbiturates .
Sources
Publications
Refereed papers
- Center S A, Slater M R, Mainwarren T et al(1992) Diagnostic efficacy of serum alkaline phosphatase and gamma-glutamyltransferase in dogs with histologically confirmed hepatobiliary disease - 270 cases (1980-1990). JAVMA 201 , 1258.
Other sources of information
- Ettinger S J & Feldman E C (eds) (2000) Textbook of Veterinary Internal Medicine. 5th edn. Philadelphia: W B Saunders & Co.
- Kaneko J J, Harvey J W & Brass M L (eds) (1997) Clinical Biochemistry of Domestic Animals. 5th edn. Boston: Academic Press.
- Duncan J R, Prasse K W & Mahaffey E A (1994) Veterinary Laboratory Medicine. Clinical Pathology. 3rd edn. Iowa: Iowa University Press.
