Influence of Cerebral Ischemia of Various Duration on Mitochondrial Respiration

Abstract

Estimation of the energy exchange parameters during partial brain ischemia offers an opportunity for finding new ways of correcting the above pathology. The aim of the study was to investigate the changes in mitochondrial respiration in the homogenates of rats with brain cerebral ischemia of various duration. The experiment was carried out on 19 white female rats in whom the right common carotid artery was ligated for 1 hour or 3 days with subsequent decapitation and brain removal. The rate of mitochondrial respiration in mitochondrial suspension of brain homogenates was assessed by means of the polarographic method using succinate or a mixture of L-malate/L-glutamate and adenosine diphosphate as respiratory substrates. Ligation of the right common carotid artery of various duration resulted in reduced mitochondrial respiration rate which was more pronounced after 1 hour of partial brain ischemia as compared to 3 hours. Modeling of partial cerebral ischemia in rats by ligation of the right common carotid artery considerably inhibits respiratory activity of the brain mitochondria leading to the dissociation of oxidation and phosphorylation in the mitochondria and inducing impairment of neuronal bioenergetics in cerebral tissue due to the disturbance of the supply of oxygen by blood. Understanding of pathophysiological processes in mitochondria during partial brain ischemia will help to develop new methods of pathogenetic correction of changes in cell structures of the brain tissue. This approach offers new possibilities for the pathogenetic therapy.