Controlled Ascent Rate Enhances Autophagy and Mitigates Acute Lung Injury in Rats Exposed to High-Altitude Hypoxia by Inhibiting Oxidative Stress and Inflammation.

The gradual ascent strategy, an effective measure to prevent acute mountain sickness by enabling the body to adapt to high-altitude hypoxia, has an unclear mechanism. This study explores controlled ascent rates' effects on autophagy, oxidative stress, inflammation, and lung injury in rats exposed to high-altitude hypoxia, hypothesizing that gradual ascent can activate autophagy, reduce oxidative stress and inflammation, and improve lung injury. 70 male Sprague-Dawley rats are divided into seven groups, including a normal control group and high-altitude hypoxia for 24, 72, and 120 h, with or without controlled ascent rates. Lung tissues are analyzed for the wet-to-dry weight ratio, histopathology, inflammatory cytokines, oxidative stress markers, and autophagy-related protein expression. Results show that controlled ascent rates reduced lung injury, oxidative stress, and inflammation in rats exposed to high-altitude hypoxia while increasing autophagy. This study indicates that gradual ascent can be an effective strategy for reducing lung injury in high-altitude areas by regulating autophagy and reducing oxidative stress and inflammation.