Expression of gamma-glutamyl transpeptidase mRNA after depletion of glutathione in rat liver.
Gamma-glutamyl transpeptidase (gamma-GT) is the enzyme in the gamma-glutamyl cycle which mediates the first step of glutathione degradation. Recently, it has been reported that diethyl maleate, a glutathione-depleting agent, enhanced hepatic gamma-GT activity. In this study, we examined how gamma-GT mRNA was expressed after the depletion of glutathione by using the RT-PCR method and in situ hybridization technique with digoxigenin-labeled oligonucleotide probe. We could detect hepatic gamma-GT mRNA in the epithelial cell of bile duct and the cytoplasm of hepatocytes in the periportal area, even in control rats. Furthermore, we found that the expression of gamma-GT mRNA was expanded to hepatocytes of a whole lobule 12 hr after depletion of glutathione by diethyl maleate, followed by the return to the pretreatment condition under which gamma-GT mRNA appears to be controlled in correlation with hepatic glutathione levels. These results suggest that the depletion of glutathione may induce hepatic gamma-GT activity through an increased synthesis of its mRNA.
Moriya
S
S
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
Nagata
S
S
Yokoyama
H
H
Kato
S
S
Horie
Y
Y
Ito
T
T
Ebihara
Y
Y
Ishii
H
H
D000818:Animals; D005978:Glutathione / Q000032:analysis / Q000235:genetics*; D017403:In Situ Hybridization; D008099:Liver / Q000737:chemistry*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D005723:gamma-Glutamyltransferase / Q000032:analysis / Q000235:genetics*
D012333:RNA, Messenger; D005723:gamma-Glutamyltransferase; D005978:Glutathione