Endothermy of organisms and subcellular mechanisms of thermogenesis

Abstract

Different ways of thermogenesis in the organism of warm-blooded organisms were considered in the review. Previous views on thermogenesis were based on the idea of low efficiency of biological processes. Subsequently it was demonstrated experimentally a fairly high efficiency of these processes. Otherwise, there would be no cold-blooded organisms and all animals were warm-blooded. At present specific mechanisms of thermogenesis are described. Uncoupling proteins (UPC) are isolated from the inner membrane of mitochondria, which increase the proton leakage of membranes, reducing the efficiency of the respiratory chain. Membrane anion-translocators also participate in proton leakage, which as a whole can increase the basal metabolism from 20 to 40%. In another group of studies on mitochondria, a greater number of oxidative substrates were used. The results showed the existence of coupled and uncoupled mitochondria. The nativity of the latter was tested on isolated rat cardiocytes. Uncoupled respiration is significantly (up to 10 times) higher in mitochondria of endotherms than one of ectotherms and it can cause maintenance of the warm-bloodedness.