[Effects of breathing high concentrations of oxygen on changes in blood indices during bicycle exercise]

The purpose of this study is to examine effects of hyperoxic gas mixtures on changes of blood indices during bicycle exercise of human. Oxygen-enriched gases (30% O2) were inspired during the ramp load exercise of 25 watt/min. Changes of blood indices were analyzed with Sequential Multiple Analyzer with the computer (SMAC). The improvement of exercise performance were discussed about relationship between function of hyperoxic gas and physiological mechanism. Three experimental conditions were set as follows (I) 30% O2 +N2 gases balance, (II) air (21% O2), and (III) 30% O2 +2% CO2 +N2 gases balance. Arterial blood were sampled from the radial artery of the forearm in order to analyze following items; 1) pH level, PaO2, PaCO2, and HCO3 of these blood gases, 2) Blood sugar, TG, and F-CH of the blood contents, 3) red blood corpuscle, white blood corpuscle, Hb, and Ht values, 4) LDH, CK, GOT, and GPT of the blood enzymes, 5) TP, ALB, Na, K, Ca and Cl of the electric ions. In the case of inspiring hyperoxic gases, the recovery rate of blood indices increased after this ramp load exercise remarkably, and the whole exercise metabolism were removed from acidosis tendency to alkalosis value of the resting condition significantly. At hyperoxic experimental conditions, the blood sugar and oxygen consumption were much more decreased than these at normal oxygen content one during both states of exercise and recovery times. These data of the blood indices would support strongly to the hypothesis that improvement of oxygen delivery should be depended upon the enhanced performance with the hyperoxic gases. There might be effects of the hyperoxia on the cellular metabolism and on function of the vascular muscle during those aerobic exercise.