The role of glutathione in metabolism of selected dimethylnaphthalenes in rat.
OBJECTIVE
Methylnaphthalenes have been used extensively as chemical intermediates in organic synthesis, as solvents for pesticides, sulphur and various aromatic compounds. A wide use of methylnaphthalenes has contributed to their emission into the environment. The aim of the study was to explain the role of glutathione in metabolism of selected dimethylnaphthalenes in rat.


METHODS
The experiments were conducted on male rats of the strain outbred IMP:WIST The animals were administered a single intraperitoneal dose (600 mg/kg body weight) of dimethylnaphthalenes (1,2-DMN; 1,3-DMN; 1,4-DMN) or dimethylnaphthalenes-[ring-U-3H]: (1,2-DMN-[3H]; 1,3-DMN-[3H]; 1,4-DMN-[3H]). The analysis was performed after 4, 8, 24, 48 h. The biochemical parameters were indicated: hepatic and pulmonary GSH, a-GST, SDH, GPX in blood, and adduct levels in the liver and lung.


RESULTS
The investigations demonstrated that a single intraperitoneal administration of dimethylnaphthalenes to rats at a dose of 600 mg/kg body weight caused a substantial depletion of reduced glutathione (GSH) level both in the liver and lung. The activity of a-glutathione S-transferases in serum of experimental animals exposed to dimethylnaphthalenes increased only after 1,2-DMN administration, the compound for which in earlier investigations the largest number of sulphur-containing metabolites was found in urine. To evidence that deep GSH depletion in analyzed organs has no oxidative nature, glutathione peroxidase activity in blood was determined.


CONCLUSIONS
Lack of changes in glutathione peroxidase and sorbitol dehydrogenase activity for all the investigated compounds suggests that significantly deep GSH depletion in liver was not of oxidative nature and did not lead to necrotic changes in produced metabolites binding with GSH.
Department of Toxicology, Medical University, Lódź, Poland.
Anna
A
Kilanowicz
Andrzej
A
Sapota
Adam
A
Daragó
D000704:Analysis of Variance; D000818:Animals; D005978:Glutathione / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007274:Injections, Intraperitoneal; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008168:Lung / Q000201:enzymology / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009281:Naphthalenes / Q000008:administration & dosage / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric
D009281:Naphthalenes; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione