Rie Tatsuki (1), Kumi Satoh (1), Atsuko Yamamoto (1), Katsuji Hoshi (1)
and Kazuo Ichihara (1,2,*)
(1) Department of Pharmacology, Hokkaido College of Pharmacy, 7-1 Katsuraoka,
Otaru 047-02, Japan
(2) Department of Clinical Pharmacology, Asahikawa Medical College, 4-5
Nishikagura, Asahikawa 078, Japan
(*) To whom correspondence should be addressed (1).
Abstract: We studied the relationship between changes in lipid
peroxides and those in catalase activity in pancreases, livers and hearts
of streptozotocin-induced diabetic rats. Animals were killed 2 or 7 weeks
after saline or streptozotocin (32 mg/kg, i.v.) injection. The levels of
blood glucose and plasma insulin in the 2-week streptozotocin-treated rats
were 176.8+/-20.5 mg/dl and 29.9+/-3.2 microU/ml, respectively. In the pancreas,
the lipid peroxide level significantly decreased and the catalase activity
significantly increased 2 weeks after streptozotocin injection. These changes
recovered after 7 weeks. In the heart, the lipid peroxide level significantly
increased without any change of catalase activity 2 weeks after the initiation
of diabetes. After 7 weeks, the catalase activity significantly increased
and the lipid peroxide level returned to the control level. In the liver,
there was no change in the lipid peroxides and catalase in the 2-week streptozotocin-treated
rats, whereas the catalase activity significantly increased 7 weeks after
the injection. It was suggested that the defense system in the pancreas
to oxidative stress may be evoked in an early stage of streptozotocin-induced
diabetes.
Keywords: Streptozotocin, Lipid peroxide, Catalase, Liver, Heart