The gamma-glutamyltransferase/glutamine synthetase activity ratio. A powerful marker for the acinar origin of hepatocytes.
The activity of glutamine synthetase (GS) in hepatocytes isolated by digitonin-collagenase perfusion from the perivenous region was more than 10-times higher than in cells isolated from the periportal region. This distribution was confirmed by immunohistochemical staining for GS of cells separated from either region. In contrast, in periportal hepatocytes, the activity of gamma-glutamyltransferase (GGT) was 3-4 times as high as in perivenous hepatocytes. This acinar distribution was also confirmed histochemically. The striking reciprocal acinar distribution of these two enzymes, now observed by direct biochemical analysis of selectively isolated hepatocytes, confirms the earlier qualitative differences observed by histochemistry and immunohistochemistry. The GGT/GS ratio seems to serve as a powerful marker of the acinar origin of isolated hepatocyte populations. Preliminary data describing glutamine synthetase activity in plasma of some subjects with suspected liver dysfunction suggests this enzyme as a marker for pericentral damage.
Lindros
K O
KO
Research Laboratories of the State Alcohol Company, Alko Ltd., Helsinki, Finland.
Penttilä
K E
KE
Gaasbeek Janzen
J W
JW
Moorman
A F
AF
Speisky
H
H
Israel
Y
Y
D000818:Animals; D015415:Biomarkers; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000201:enzymology*; D008297:Male; D051381:Rats; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D015415:Biomarkers; D005723:gamma-Glutamyltransferase; D005974:Glutamate-Ammonia Ligase