The erythrocytes represent an important source of antioxidant capacity of the blood. Catalase (EC 1.11.1.6.) is one of the enzymatic components of their antioxidant defense system. The objective of this study was to follow erythrocyte catalase (CAT) in 7-, 15-, 21-, 35-, 60- and 90-day-old Wistar rats of both sexes in normoxia and after exposure to intensive acute hypobaric hypoxia. During the development CAT activity increases in both sexes, but the rise was usually higher in females. Hypobaric hypoxia increased CAT activity in all studied age groups of both sexes. However, higher CAT activity in females was less affected by hypoxia than the lower activity in males. This was true for nearly all age groups studied. It can be concluded that both ontogenetic aspects and sex differences play a major role in establishing the activity of CAT, which is an important part of the antioxidant defense of the organism.

Institute of Physiology Academy of Sciences of the Czech Republic and Center for Cardiovascular Research Prague Czech Republic

Activity of lactate dehydrogenase in serum and cerebral cortex of immature and mature rats after hypobaric hypoxia