Acute Hyperbaric Oxygenation, Contrary to Intermittent Hyperbaric Oxygenation, Adversely Affects Vasorelaxation in Healthy Sprague-Dawley Rats due to Increased Oxidative Stress

Figure 1

ACh-induced relaxation (AChIR) of isolated rat aorta rings in the CTRL, A-HBO₂, 24H-HBO₂, and 4D-HBO₂ groups. AChIR was significantly impaired in the A-HBO₂ group when compared to the other groups of rats with a 10⁻⁹–10⁻⁵ M ACh concentration. A-HBO₂ rats exhibited lower sensitivity to ACh compared to other groups of rats (table). Half maximal effective concentration (EC50) presents concentration of ACh (M) which induces a response halfway between the baseline and maximum. LogEC50 values (shown in the corresponding tables) were compared by a one-way ANOVA test.