SOME ASPECTS OF MOLECULAR-CELLULAR REGULA TION OF THE MITOCHONDRIAL RESPIRATORY-CHAIN

We propose a new concept of molecular-cellular regulation of the mitoc hondrial respiratory chain. According to this concept, the cell uses a cetaldehyde (AcA) as a main regulator of the respiratory chain. AcA ex presses its action by changing the structural-functional state of ubiq uinone, the key component of the respiratory chain. Studies were made on white random bred rats using the Langendorf's model of isolated per fused heart. We comparatively estimated the mechanometabolic state of myocardium under the conditions of simulated hypoxia of various degree , as well as in the presence of exogenous ethyl alcohol. Both hypoxia and ethyl alcohol induced sever disturbances of energy metabolism in t he myocardium, cells at the level of respiratory chain due, apparently , to the increased content of free AcA. Hydroxyquinone and glycine, ca pable of binding free AcA, were used for pharmacological protection of the cells. Application of these drugs markedly improved the functiona l-metabolic state of the cell. We propose that AcA exerts both regulat ory (in low doses) and inhibitory (in high doses) effect on the respir atory chain. The results obtained allow a novel insight in the process es of alcoholic and hypoxic damage and their pharmacological correctio n. It is evident that prophylactic and therapeutic measures in case of hypoxia or alcoholic intoxication should be first directed at decreas ing the level of free AcA in the cell.