新西兰兔对极快速减压的耐受能力和损伤特点分析

Analysis on tolerance and injury features in New Zealand rabbits following rush decompression

目的探讨极快速减压时机体的耐受能力及主要器官肺、脑的损伤特点。方法25只新西兰兔按数字表法随机分为对照组（5只）和极快速减压组（20只），极快速减压组动物单只进入低压舱，分别在减压前、极快速减压过程中和减压后观察动物行为变化，记录压力值、减压速度和减压时间。在加压前及减压后15min抽取动脉血，ELISA法测定血清中肺泡表面活性物质结合蛋白A、脑型肌酸激酶含量，计算肺组织湿干质量比，HE染色法观察兔肺及脑组织的病理改变。结果20只新西兰兔在120S内从常压环境极快速减压至30kPa以下，6只兔（30％）死亡，其中4只兔在10rain内死亡（称为10rain死亡组），2只分别在100min和144min死亡（称为2h死亡组），70％动物存活。极快速减压后兔肺、脑组织明显水肿，2h死亡组肺水肿、肺充血程度最重，肺湿干质量比显著升高，10min死亡组脑内可见大量神经元急性坏死。死亡组血清sP—A浓度显著增高，其中2h死亡组高于10min死亡组（P〈0．05）。极快速减压后动物血清CK．BB浓度显著增高，其中10min死亡组明显高于2h死亡组和存活组（P〈0．05）。结论极快速减压可造成新西兰兔严重的肺、脑组织损伤，具有不同的伤情特点，可为救治措施研究提供依据。

Objective To explore tolerance and injury features of the lung and brain in rabbits following rush decompression. Methods A total of 25 New Zealand rabbits were randomly divided into 2 groups ： the control group （ n = 5 ） and the rush decompression group or RD group （ n = 20）. The rabbits of the RD group were individually exposed in the hypobarie chamber. Then, changes in animal behavior, pressure data, decompression rate and decompression time were observed and recorded both before decompression, during the course of rush decompression and after decompression. Arterial blood samples were taken both before compression and 15 minutes after decompression. Levels of surfactant-associated protein A and creatine kinase BB isozyme were detected in serum before and after exposure by ELISA. Lung tissues were taken for determination of the wet/dry ratio of the pulmonary tissue, and pathological changes in the lung and brain tissues were also closely detected with HE staining. Results When the animals experienced rush decompression from atmospheric pressure （lO0kPa） to a pressure lower than 30 kPa in 120 seconds, 30% of the animals died withinl0 minutes or 2 hours after decompression, 70% of them survived. Following rush decompression, serious edema could be observed in the pulmonary and brain tissues of the exposed animals.Very serious pulmonary edema and hyperemia could be noted in the animals that died within 2 hours. Wet/dry ratio of the puhnonary tissue increased significantly. Acute necrosis of large quantities of neurons was clearly visible in the brain tissue of the animals that died within 10 minutes. Concentration of serum surfactant protein A （SP-A） in the animals that died following rush decompression increased markedly, with the concentration of （SP-A） in the animals that died 2 h after decompression being higher than that of the animals that died 10 min after decompression（P 〈 0.05）. The concentrations of serum creatine kinase BB isozyme （CK-BB） increased notably, following rush decompression, with the concentration of CK-BB in the animals that died l0 min after decompression being obviously higher than that of the animals that died in 2 hours or survived following decompression（ P 〈 0. 05 ）. Conclusions Rush decompression could result in serious tissue damage to pulmonary and brain tissues in rabbits, and different injury features could provide evidence for the development of medical treatment measures.