Hyperbaric oxygen pretreatment benefits on decompression sickness in Bama pigs

Abstract

Decompression sickness (DCS) occurs when ambient pressure is severely reduced during diving and aviation. Hyperbaric oxygen (HBO) pretreatment has been shown to exert beneficial effects on DCS in rats via heat-shock proteins (HSPs). We hypothesized that HBO pretreatment will also reduce DCS via HSPs in swine models. In the first part of our investigation, six swine were subjected to a session of HBO treatment. HSP32, 60, 70 and 90 were detected, before and at 6, 12, 18, 24 and 30 h following exposure in lymphocytes. In the second part of our investigation, another 10 swine were randomly assigned into two groups (five per group). All swine were subjected to two simulated air dives in a hyperbaric chamber with an interval of 7 days. Eighteen hours before each dive, the swine were pretreated with HBO or air: the first group received air pretreatment prior to the first dive and HBO pretreatment prior to the second; the second group were pretreated with HBO first and then air. Bubble loads, skin lesions, inflammation and endothelial markers were detected after each dive. In lymphocytes, all HSPs increased significantly (<0.05), with the greatest expression appearing at 18 h for HSP32 and 70. HBO pretreatment significantly reduced all the determined changes compared with air pretreatment. The results demonstrate that a single exposure to HBO 18 h prior to diving effectively protects against DCS in the swine model, possibly via induction of HSPs.

Ulinastatin: A Potential Alternative to Glucocorticoid in the Treatment of Severe Decompression Sickness

“…IL-1β is one proximal factor responsible for downstream cytokine production and vascular injuries induced by decompression (Thom et al, 2018). MCP-1 is another proinflammatory cytokine in the process of disease resistance, which is related to decompression stress (Qing et al, 2018). UTI treatment significantly decreased the elevated serum levels of IL-1β and MCP-1 and, hence, in this study relieved inflammation cascade reactions induced by DCS.…”

“…The inflammatory, endothelial and oxidative indices in this study were mainly selected based on our previous studies in rat and swine DCS models (Zhang et al, 2017;Qing et al, 2018Qing et al, , 2019. In accordance with our swine model, all biochemical indices showed similar changes to those seen in rats except for E-selectin, which showed no change in the rabbit and swine DCS model.…”

Benefits of Escin for Decompression Sickness in Bama Pigs by Endothelial-Targeting Protection

“…The surgery procedure was the same as in a previous study (Qing et al, 2018). Briefly, after the experimental animal calmed down, anesthesia was conducted with 0.05 mg/kg atropine and 0.1 ml/kg Sumianxin intramuscularly injected with an interval of 15 min; 2 mg/kg propofol was injected intravenously, and anesthesia was maintained with inhaled 6% isoflurane using an anesthetic machine (WATO EX-20 Vet, Mindray, Shenzhen, China).…”

“…To prevent any decrease in O 2 and accumulation of CO 2 , the chamber was frequently ventilated. During exposure, the temperature was maintained between 22 and 24°C with transient minor changes following compression and near surfacing (Qing et al, 2018).…”

“…Briefly, the latency was recorded, and the dimensions of stage III lesions were measured by the palm of a single experimenter. Swine body surface area was calculated by the Meeh–Rubner equation area = 0.0974 × weight 2/3 (Quiring, 1955; Qing et al, 2018).…”