Effects of acute hypoxia and hyperoxia on antioxidant defense system in gills of carps (Cyprinus carpio L.)

Abstract

In our experiments conunon carps (Cyprinus carpio L.) were acclimated to an oxygen concentration of 7.3 lmg/L water (100%) - control (C) group. Two ex­ perimental groups (H1, H2) were exposed to acute hy­ poxia. One of them was exposed to a progressive reduc­tion of 02 to 4.1 O2 mg/L (55%) for 1 ¼ hour s and another 1.95mg/L (25%) for 2 hours, respectively. The fourth experimental group (HP) was exposed to a progressive increase of oxygen concentration O2 to 10 mg/L (150%) for I5 minutes, respectively. In our exper iment was determinated antioxidant defense· s yste m enzymes activity (superoxide-dismutase (SOD), catalase (CAT) glutathione-peroxidase (GSH-Px) , and glutathione-reductase (GR) and glutathione-S-transferase (GST) ac­ tivity (Misra, H.P. and Fridovich, I. (19 72), Beutler (1982), Tamure et al. ( I982), Habig et al. (1974), Glatzle et al. (1974). Our res ult s show that stress caused by acute hypoxia and hyperoxia significantly changes the activities of antioxidant defense system enzymes, superoxide-dis­mutase (SOD), glutathione-peroxidase (GSH-Px), and glutathione-reductase (GR) in carps gills. Acute pro­ longed hypoxia (H2) caused a cetrain degree of adapta­tion in respect to catalase (CAT) and glutathione-S­ transferase (GST) activity .