Biomedical Engineering Reference
In-Depth Information
oxidative stress (when the antioxidant capability of the target cell
becomes insufficient to prevent the increased formations of reactive
oxygen species (ROS)). The antioxidant status was evaluated by the
increase in lipid peroxidation and a decrease of enzymatic and non-
enzymatic antioxidants.
In one study, male Wister rats received 1.5 gm/kg bw methanol by
gavage. Groups of six rats were sacrificed at 6, 12, 24, 48, 120, and
168 hours after dosing and antioxidant enzyme activity as well as
ascorbate,
a
-topcopherol, nonprotein, and protein bound sulfhydryl
compounds levels were determined in liver, erythrocytes, and serum. In
addition, blood pH, lipid peroxidation (thiobarbituric acid reacting
substances (TBA), and liver cytotoxicity was also measured. In the
liver superoxide dismutase (SOD) did not change, while (CAT) activity
in the liver increased at 6 and 12 hours and then returned to normal.
Glutathione peroxidase (GSH-Px) was significantly decreased at 24
and 48 hours, while glutathione reductase (GSsG -R) was decreased
6-24 hours in each group. Nonprotein and protein bound sulfhydryl
compounds were reduced at 12-120 hours and ascorbate concentration
was decreased only at 12 hours. Lipid peroxidation (TBA) was
increased from 12 to 48 hours in the liver after oral dosing.
In the red blood cells, antioxidant enzyme level and ascorbate,
a
-topcopherol, nonprotein, and protein bound sulfhydryl compounds
levels were decreased except for CAT, which was increased at 6 and
12 hours. TBA reactive substances were increased from 6 to 120 hours.
In the serum, SOD was increased during the first 24 hours and the
other antioxidant enzymes and ascorbate,
a
-topcopherol, nonprotein,
and protein bound sulfhydryl compounds levels were decreased. TBA
reactive substances were increased up to 120 hours.
Blood pH was increased at 6 hours after dosing and then decreased
falling below control level by 48 hours. Serum aspartate amino-
transferase and alanine aminotransferase levels were also increased
indicating liver damage.
This study demonstrates that in addition to damaging the liver in rats,
that methanol impairs antioxidant defenses in the liver, erythrocyte, and
serum following a single oral dose of 1.5 gm/kg bw of methanol
(Skrzydlewska and Farbiszewski, 1996).
