T01-P-03 Gender-specific changes in energy metabolism in rat liver mitochondria

Abstract

We examined the effect of 30 min immobilization stress on respiration rate, activity of succinate dehydrogenase (SDH) and citratsyntase (CS) in the liver mitochondria in adult female and male rats. The rate of respiration in mitochondria was measured with oxygen electrode with succinate(SUC), a-ketoglutarate (KGL) and a-ketoglutarate+ malonate as substrates. Our data showed that basal level of respiration rate in state 3 was higher in female than in male mitochondria by 28% with SUC as a substrate. With KGL, gender differences were not pronounced. The uncoupler activated increasing in respiration rate amount 67% in males and 95% in females. The acute stress caused increase in respiration rate in state 3 with SUC in males mitochondria by 62%. However in females mitochondria, this effect was not revealed. The degree of uncoupled respiration rate remained invariable for both genders. The acute stress didn’t change oxidation rate of KGL. It was showed that the basal SDH activity was higher in female than in male by 35%. Immobilization led to increase in SDH activity. The SDH activity increased by 56% in males and 30% in females. Basal citrate synthesis rate was higher in female vr. male by 20%. The CS activity in stressed males was increased by 25% and 40% in females. Thus, our data suggest that activity of examined mitochondrial enzymes are sexually differentiated. It may cause more significant increase in reactive oxygen species production in males in comparison with females under acute stress. Supported by Grant MORF- 02.512. 11.2111