The effect of brief food withdrawal on the level of free radicals and other parameters of oxidative status in the liver.

Background: The aim of our study was to determine the effect of brief starvation on the level of free radicals and other parameters of oxidative status in the liver.

Material/methods: The Wistar male rats used for the experiment were divided into two groups: Group I had free access to water and standard chow, while Group II was subjected to a 36-hour fast. The activity of antioxidant enzymes--catalase (CAT), glutathione peroxidase (GSH-Px) and Cu, Zn-superoxide dysmutase (CuZn-SOD)--was measured in the livers of both control and fasting animals. The hepatic level of free radicals and the concentration of malonyldialdehyde (MDA) were also determined in both groups of animals.

Results: Starvation resulted in decreased activity of CAT and CuZn-SOD, while the GSH-Px activity remained unchanged. Food deprivation also increased the level of free radicals. However, this rise was not paralleled by enhanced hepatic lipid peroxidation, measured as a change in MDA content.

Conclusions: Since brief starvation causes an increase in the level of free radicals in the liver, it appears to effectively impair the tissue defence system, in part through the decreased activity of antioxidant enzymes, CAT and CuZn-SOD.