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PubMed1983

["In vitro" effect of CCl4, PG and EDTA on GSH levels at different time of incubation of rat liver homogenates].

During CCl4-induced lipid peroxidation GSH content in total homogenate from rat liver falls very rapidly in the first 30 min. of incubation "in vitro". CCl4 does not enhance the decrease in total glutathione (TG) during the incubation time, so GSH loss is mainly due to its oxidation to GSSG. On the contrary PG and EDTA, two substances decreasing lipid peroxidation rate, are able to decrease GSH oxidation, without affecting TG content. At 25 degrees C EDTA and PG completely prevent GSH decrease at pH 7.4, while at pH 6 PG affords only a partial prevention. At 37 degrees C both compounds are able to limit GSH decrease at a large extent. Lipid peroxidation seems to have a great importance in the kinetics of GSH decrease and GSSG formation, at least "in vitro". It is noteworthy that PG which inhibits lipid peroxidation stimulated by CCl4 is also able to limit the high GSH loss observed in the homogenates incubated in the presence of halogeno-alkane.

Animals↗

PubMed1983

[Kinetics of sulphur compounds decrease in liver homogenates during in vitro incubation in experimental conditions modifying lipid peroxidation rate].

Low values of pH are known to increase lipid peroxidation during "in vitro" incubation of rat liver homogenates. Non protein sulphydryl compounds decrease more rapidly when the pH of the homogenate is lower. The increase in incubation temperature stimulates the production of TBArs. At high temperature values the -SH groups content of liver tissue falls quickly; the rate of this fall, at the same temperature values, shows differences at different pH. In all experimental conditions the decrease of -SH groups precedes the stimulation of TBArs production and it is mainly due to GSH oxidation, being the decrement of total glutathione very low. Total homogenate from Yoshida AH-130 hepatoma shows no production of GSSG even when incubate for 2 hours at 40 degrees C and at pH 6. The importance of the role played by carbonyl compounds arising from peroxidative decomposition of unsaturated fatty acids on GSH decrement in liver homogenates is discussed and the difference between Yoshida hepatoma and normal liver, as far as GSH decrease is concerned, is discussed.

Animals↗