Gamma-glutamyltranspeptidase (GGT) in experimental liver cirrhosis induced by thioacetamide: a biochemical and enzymehistochemical study.
Micro- and macronodular experimental cirrhosis-like liver lesion was induced in female rats by administration of 0.03% thioacetamide (TAA) in drinking water for 3 or 6 months. The activity of gamma-glutamyltranspeptidase (GGT) and the distribution pattern of this enzyme within the liver structure were investigated 14 d after withdrawal of TAA in comparison to neonatal and adult normal liver. GGT activity was extremely high at birth. Chronic TAA administration led to a strong increase in hepatic GGT activity in dependence on duration of TAA administration in comparison to adult controls. In accordance to these results we observed by enzyme-histochemistry a small to moderate hepatocellular GGT activity after 3 months of TAA treatment. GGT activity was also demonstrable in epithelia of proliferated ductuli biliferi of single enlarged portal tracts. After 6 months of TAA administration the hepatocellular GGT activity was moderate to strong. It was demonstrable both in parenchymal (preneo-plastic) nodules and in cholangiocellular/cholangioductular proliferates. A GGT activity of mesenchymal cells was not demonstrable. We conclude that the increased hepatic GGT activity after chronic TAA administration can be correlated with the process of development of preneoplastic nodules. A relation between increased GGT activity and the process of cirrhogenesis does not seem to be probable in this animal cirrhosis model.
Friedrich Schiller University, Institute of Pharmacology and Toxicology, Jena, Germany.
M
M
Kretzschmar
G
G
Machnik
D
D
Oesterle
T
T
Zimmermann
W
W
Klinger
D000818:Animals; D005260:Female; D006651:Histocytochemistry; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013853:Thioacetamide; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D013853:Thioacetamide; D005723:gamma-Glutamyltransferase