Biomedical Engineering Reference
In-Depth Information
In a later study of similar design, male Wistar rats received
3 gm/kg bw of methanol. Rats were scarified at 6, 14, 24, 48, 120,
and 168 hours after dosing and antioxidant enzyme activity as well as
ascorbate,
a
-topcopherol, malonaldehyde (MDA) were determined in
liver, erythrocytes, and serum. GSH-Px, GSsG-R, GSH, and ascorbate
concentrations were significantly decreased in the liver, erythrocyte,
and in the blood serum, while CAT and SOD increased initially and the
returned to normal by 48 hours after dosing. SOD and
a
-topcopherol in
the erythrocytes were decreased, while MDA in the liver, erythrocyte,
and serum were elevated. This study at twice the dose as the previous
study also supports that methanol impairs some enzymatic and
nonenzymatic antioxidant defenses in the liver, erythrocyte, and
serum following a single oral dose of 3.0 gm/kg bw of methanol
(Skrzydlewska and Farbiszewski 1998).
In a short-term study in rats, 6 gm/kg bw of methanol (as a 50%
solution in isotonic saline) was given by gavage to groups of six male
Wistar rats. A group was sacrificed at 6, 12, 24 hours and 2, 5, or 7 days
after treatment. Brain and liver were removed and enzyme assays were
conducted for superoxide dismutase (SOD), glutathione peroxidase
(GSH-Px), glutathione reductase (GSsG -R), and catalase (CAT) in
each group. Glutathione (GSH) and ascorbate concentration were also
determined at each time point. Lipid peroxidation was assayed as
thiobarbituric acid reacting substances (TBA).
SOD activity was significantly depressed after 2 and 5 days returning
close to normal by day 7 in the brain. SOD activity was increased at
hour 6, 12, and 24 and then returning close to normal in the liver.
(GSH-Px) and (GSSG -R) activity in the brain was initially increased
for the first 24 hours then returned to normal, while in the liver
(GSH-Px) and (GSSG -R) activity was decreased throughout most of
the 7 days after treatment. CAT levels were not significantly affected in
the brain during the 7-day period, but increased in the liver reaching a
peak at day 5 before returning to normal on day 7.
GSH was decreased in both the brain and liver during most of the
7-day period with the biggest decrease seen in the brain during the
day at day 7 and in the liver at 24 hours. Ascorbate decreased in both
the brain and liver with a decrease seen in the brain at 12 hours and in
