Impaired glutathione biosynthesis in the ischemic-reperfused rabbit myocardium.
Non-protein thiols (NP-SH) and the activities of the glutathione status-regulating enzymes gamma-glutamylcysteine synthetase (G-GCS), gamma-glutamyl transpeptidase (G-GT) and glutathione reductase (GR) were assessed in perfused rabbit hearts subjected to severe (60 min) or mild (7 min) total ischemia and 30 min reperfusion. Severe ischemia significantly decreased NP-SH, which were further depressed on reperfusion together with a significant decline in G-GCS activity; G-GT and GR activities were unchanged. Specific analytes were unaffected by mild ischemia-reperfusion. Thus, impaired enzymatic biosynthesis of GSH is operative in the reperfused rabbit myocardium after 60 min ischemia. This phenomenon may favour myocardial GSH depression and oxidative reperfusion injury after severe ischemia.
Lapenna
D
D
Istituto di Fisiopatologia Medica, Università G. D'Annunzio, Facoltà di Medicina e Chirurgia, Chieti, Italy.
de Gioia
S
S
Ciofani
G
G
Mezzetti
A
A
Pierdomenico
S D
SD
Di Ilio
C
C
Cuccurullo
F
F
D000818:Animals; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D005978:Glutathione / Q000096:biosynthesis*; D005980:Glutathione Reductase / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D017202:Myocardial Ischemia / Q000378:metabolism; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D011817:Rabbits; D012016:Reference Values; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D013438:Sulfhydryl Compounds; D005980:Glutathione Reductase; D005723:gamma-Glutamyltransferase; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione