Gillmore J D, Walker R I
Undersea Biomed Res. 1977 Mar;4(1):67-73.
Swiss albino mice were exposed to normoxic (PO2 approximately 0.2 ATA) helium at 1, 20 or 35 ATA for 2 or 48 h and examined for the presence of bacteria and endotoxin in selected tissues. Among mice exposed to 35 ATA for 48 h and tested immediately after decompression for bacteria in liver and peritoneal cavities, 6 of 30 (20%) contained gram-negative rods and 27 of 30 (90%) contained gram-positive cocci. Incidence of infection was considerably less in mice exposed to 35 ATA for 2 h or exposed to 1 ATA. Evidence of presence of gram-negative rods and /or escape of free endotoxin from the intestine was provided by demonstration that limulus lysate is coagulated (presumptive evidence of endotoxin) by liver homogenates in 70% of the mice exposed to 35 ATA for 48 h, 68% of those exposed to 20 ATA and 14% of those exposed to 1 ATA. Mice subjected to the hyperbaric stress of 35 ATA for 48 h were shown to be increasingly susceptible to injection with purified lipopolysaccharide. The LD50 was 0.24 mg for hyperbaric exposed mice and 0.39 mg for the control groups. These data suggest that hyperbaric stress, but not necessarily decompression, results in a short-term presence in mouse tissues of microbial agents originating from the gut. This invasion temporarily renders that host more susceptible to additional endotoxic challenge.
将瑞士白化小鼠暴露于常氧（PO2约0.2ATA）的氦气中，压力分别为1、20或35ATA，持续2或48小时，然后检查选定组织中细菌和内毒素的存在情况。在暴露于35ATA 48小时并在减压后立即检测肝脏和腹腔中细菌的小鼠中，30只中有6只（20%）含有革兰氏阴性杆菌，30只中有27只（90%）含有革兰氏阳性球菌。暴露于35ATA 2小时或暴露于1ATA的小鼠感染发生率明显较低。通过证明鲎试剂被70%暴露于35ATA 48小时的小鼠、68%暴露于20ATA的小鼠和14%暴露于1ATA的小鼠的肝脏匀浆凝固（内毒素的推定证据），提供了革兰氏阴性杆菌存在和/或游离内毒素从肠道逸出的证据。结果显示，经受35ATA 48小时高压应激的小鼠对注射纯化脂多糖越来越敏感。高压暴露小鼠的半数致死量为0.24mg，对照组为0.39mg。这些数据表明，高压应激而非减压导致小鼠组织中短期存在源自肠道的微生物因子。这种侵袭使宿主暂时更容易受到额外的内毒素攻击。
