Korean J Aerosp Environ Med.
2000 Jun;10(2):113-119.
Mechanism of Renal Oxidative Damage following 4-week Head-down Suspension
in Rats
- Affiliations
-
- 1Department of Physiology, Keimyung University School of Medicine,
Taegu 700-712, Korea.
- 2Department of Biochemistry, Keimyung University School of Medicine,
Taegu 700-712, Korea. jhbae@dsmc.or.kr
Abstract
-
The purpose of this study was to observe the variation of malondialdehyde (MDA),
an indirect index of oxidative damage, following 4-week of head-down suspension (HDS)
at -45degreein rats as a model of simulated weightlessness. We also measured the activities
of antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase
(GSH-Px) and catalase for clarifying the mechanisms of renal oxidative damage. MDA was
increased (p<0.05) at the 4th week of HDS rats compared to control horizontal positioned rats.
Following HDS, the renal activity of SOD was also significantly increased (p<0.01) at the 4th
week of HDS whereas the changes of renal GSH-Px and catalase activities were not significantly
different from controls. The expression of renal SOD mRNA used by polymerase-chain reaction
method showed the similar pattern with the change of renal SOD activity and was more
increased (p<0.05) than control horizontal positioned rat. These results indicate that
simulated weightlessness induces the augmented SOD gene expression in the kidney which results
in increased SOD activity, and thus increased production of MDA due to increased production
of hydrogen peroxide. And under this condition, GSH-Px and catalase do not play their
protective roles against hydrogen peroxide.