Open Access6‐Hydroxydopamine‐induced glutathione alteration occurs via glutathione enzyme system in primary cultured astrocytes 1
Author(s) -
ZHANG Ji,
HU Jun,
DING Jianhua,
YAO Honghong,
HU Gang
Publication year - 2005
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2005.00124.x
Subject(s) - glutathione , hydroxydopamine , glutathione reductase , glutathione peroxidase , medicine , enzyme , chemistry , enzyme assay , endocrinology , biology , biochemistry , dopamine , dopaminergic
Aim: To define the role of enzymes involved in glutathione metabolism in 6‐hydroxydopamine (6‐OHDA)‐induced glutathione alteration in primary cultured astrocytes. Methods: Total glutathione (GSx) levels were determined using the modified enzymatic microtiter plate assay. The mRNA levels of γ‐glutamylcysteine synthetase (γGCS), γ‐glutamyltransferase (γGT), glutathione peroxidase (GPx), GR (glutathione reductase), and glutathione transferases (GST) were determined using RT‐PCR. γGT activity was determined using γGT assay kits. Results: In primary cultured astrocytes, 6‐OHDA induced a significant elevation of cellular GSx levels after treatment for 24 h. However, the GSx levels decreased after 24 h and the values were even lower than the value in the control group without 6‐OHDA at 48 h. RT‐PCR data showed that the mRNA levels of γGCS, the rate‐limiting enzyme of γ‐ L ‐glutamyl‐ L ‐cysteinylglycine (GSH) synthesis, were increased by 6‐OHDA after treatment for 24 h and 48 h; the mRNA levels of GPx, GR, and GST did not alter in 6‐OHDA‐treated astrocytes after treatment for 24 h and 48 h; and 6‐OHDA increased the mRNA levels and the activity of γGT after treatment for 48 h, which induced a decrease in GSx levels, despite the up‐regulation of γGCS after exposure to 6‐OHDA for 48 h. Conclusion: The change in γGCS correlated with the increase in GSH levels induced by 6‐OHDA after treatment for 24 h. GSx levels decreased because of increased γGT mRNA levels and γGT activity induced by 6‐OHDA after treatment for 48 h.