Characterization of Respiratory Function of Liver Mitochondria Isolated From Elderly Zucker Fatty Rats

摘要

In the past decade mitochondria dysfunction has emerged as central to the pathogenesis of obesity related disorders and ageing. The aim of the present study was to examine whether gender differences occur in respiratory function of liver mitochondria isolated from elderly Zucker fatty (ZF) rats. Mitochondrial respiration was measured at 37oC using a Clark-type oxygen electrode in the presence of complex I substrates (glutamate/malate, G/M) and, the complex II dependent substrate (succinate plus rotenone, S/Rot). Basal (State 2) and ADP-stimulated (State 3) respiratory rates were recorded and expressed as natoms O2/min/mg of mitochondrial protein. Integrity of mitochondria was checked by means of cytochrome c addition. No changes in State 3 respiratory rates were recorded in the presence of complex I substrates for either female or male ZF rats. However, in both ZF groups active respiration was significantly increased vs. the controls when succinate was used as respiratory substrate. Also, in female (but not in male) ZF liver mitochondria respiring on complex II substrate a significant uncoupling effect was recorded as compared to the lean rats. In conclusion, gender differences occur in adaptation of respiratory function of liver mitochondria isolated from elderly Zucker obese rats.