ROLE OF HEPATIC GAMMA-GLUTAMYL-TRANSFERASE IN THE DEGRADATION OF CIRCULATING GLUTATHIONE - STUDIES IN THE INTACT GUINEA-PIG PERFUSED LIVER

Simple item page
dc.contributor.authorSPEISKY, H
dc.contributor.authorSHACKEL, N
dc.contributor.authorVARGHESE, G
dc.contributor.authorWADE, D
dc.contributor.authorISRAEL, Y
dc.date.accessioned2025-01-23T19:23:14Z
dc.date.available2025-01-23T19:23:14Z
dc.date.issued1990
dc.description.abstractThe role of hepatic .gamma.-glutamyltransferase in the breakdown of circulating glutathione was studied in the perfused guinea pig liver. Hepatic .gamma.-glutamyltransferase activity in the guinea pig is seven-fold higher than in the rat and is comparable to its activity in man. Guinea pig livers were found to remove, in a single pass, 50% to 90% of glutathione (10 to 50 .mu.mol/L) added to the portal perfusate. Removal of portal glutathione was totally dependent on the activity of .gamma.-glutamyltransferase and led to the near quantitative appearance of cysteinyl-glycine and cysteine in the caval perfusate. Glutathione removal by the intact liver followed saturation with a Michaelis constant (Km) of 59 .mu.mol/L for glutathione and a maximum velocity of 235 nmol glutathione/min/gm of liver weight. The capacity of the guinea pig liver to remove circulating glutathione was estimated to be sevenfold to 10-fold higher than its net rate of output of glutathione into the circulation. Inhibition of .gamma.-glutamyltransferase activity in the perfused liver led to threefold to sixfold increases in the hepatic output of glutathione into the circulation, indicating that more than two thirds of glutathione transported extracellularly is broken down. Data obtained demonstrate a major role of hepatic .gamma.-glutamyltransferase, both in the removal of portally carried glutathione and in the degradation of glutathione molecules released by the liver itself into the sinusoids. These findings suggest the existence of an intraorgan transport of glutathione in the liver, whereby periportal cells could provide glutathione precursors to pericentral cells.
dc.fuente.origenWOS
dc.identifier.eissn1527-3350
dc.identifier.issn0270-9139
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/99182
dc.identifier.wosidWOS:A1990DG81800019
dc.issue.numero5
dc.language.isoen
dc.pagina.final849
dc.pagina.inicio843
dc.revistaHepatology
dc.rightsacceso restringido
dc.subject.ods03 Good Health and Well-being
dc.subject.odspa03 Salud y bienestar
dc.titleROLE OF HEPATIC GAMMA-GLUTAMYL-TRANSFERASE IN THE DEGRADATION OF CIRCULATING GLUTATHIONE - STUDIES IN THE INTACT GUINEA-PIG PERFUSED LIVER
dc.typeartículo
dc.volumen11
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
Files
Collections
Artículos de revistas