Tissue oxygen exchange and oxidative processes in long-livers: Age-related peculiarities

Abstract

The age-related peculiarities of tissue-oxygen exchange and oxidative processes in long-livers who were assumed to be physiologically aging individuals have been studied. Tissue oxygen served as the indicator of tissue oxygen exchange, which was measured by the polarographic method in the subcutaneous cellular tissue of the forearm while performing 10-min oxygen inhalation tests (with a spontaneous oxyhemogram recording) and a 10-min clamping of forearm vessels. This approach presents the opportunity to evaluate oxygen delivery and uptake. In order to quantitatively characterize oxidative processes, vacat-oxygen was assessed in the blood and urine, and the underoxidation coefficient proposed by Muller was estimated. It was established that the intensity of tissue respiration slows down, the amount of underoxidized products in the blood and urine rises, and the underoxidation coefficient increases with aging. The age-related decrease in the intensity of tissue respiration in subcutaneous cellular tissue indicates the development of tissue hypoxia due to reduced activities of enzymes that participate in the oxygen exchange process. The age-related reduction during tissue perfusion results in the formation of circulatory hypoxia, and contributes significantly to the formation of tissue hypoxia. These changes in oxygen exchange and oxidative processes in tissue detected for long-living individuals generally correspond to those seen in individuals aged 80–89. This finding makes it possible to speak on physiological aging in long-livers.