Alteration of Predominant Gastrointestinal Flora and Oxidative Damage of Large Intestine Under Simulated Hypobaric Hypoxia
Alteration of Predominant Gastrointestinal Flora and Oxidative Damage of Large Intestine Under Simulated Hypobaric Hypoxia
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DOI：
10.1055/s-0033-1336007
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发表时间：
2014-02-01
影响因子：
1.3
通讯作者：
Mondal, K. C.
中科院分区：
文献类型：
--
作者：
Adak, A.;Maity, C.;Mondal, K. C.
低压缺氧是急性高山病的直接和关键的启动机制，包括一些非特异性胃肠道（GI）并发症。为了研究缺氧对胃肠道菌群的影响及其对该系统的影响，将雄性白化大鼠连续30天暴露于55 kPa（气压~ 4872.9 m海拔）下，每天8小时。列举大肠微生物种群的不同指标组，并与大肠上皮细胞过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、丙二醛（MDA）、还原性谷胱甘肽（GSH）、氧化性谷胱甘肽（GSSG）等抗氧化指标水平进行相关性分析。此外，采用血红素伊红（HE）、周期性酸希夫染色（PAS）和扫描电镜（SEM）进行组织学研究。缺氧胁迫30 d后，总需氧菌密度（104倍）显著降低（p < 0.05），总厌氧菌密度（209倍）和大肠杆菌数量（125倍）显著升高。严格的厌氧菌，如双歧杆菌。(3折),Bacteroidesspp。(134折),Lactobacillusspp。（7倍）和其他选定的专性厌氧菌，如产气荚膜梭状芽胞杆菌（40倍）、胃链球菌。（21倍）。厌氧菌群的生长方向指数（GDI）与产气倾向呈正相关。大肠上皮组织CAT和SOD活性显著降低（p < 0.05）， GSH/GSSG池呈氧化态，MDA含量升高（p < 0.05）。组织学研究显示，上皮坏死，鼻膜内淋巴细胞浸润增多，分泌酸性粘蛋白的杯状细胞减少。从本实验可以推测，高海拔缺氧对细菌印记的影响和大肠上皮屏障的破坏可能导致全身性感染。
Hypobaric hypoxia is an immediate and crucial starting mechanism of acute mountain sickness included with some non-specific gastrointestinal (GI) complications. To study the effect of hypoxia on GI microflora and its upshot to this system, male albino rats were exposed to 55 kPa (air pressure ~ 4872.9 m altitude) consecutively 30 days for 8 hours/day. The different indicator group of large intestinal microbial populations were enumerated and correlated with the levels of antioxidant indicators like catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH) and oxidized glutathione (GSSG) of large intestinal epithelial cells. In addition, the histological study was performed by haematoxylin eosin (HE), periodic acid schiff staining (PAS) and scanning electron microscopy (SEM). It was observed that the density of total aerobes (104 folds) significantly (p < 0.05) decreased but the population of total anaerobes (209 folds) andEscherichia coli(125 folds) elevated after 30 days of hypoxic stress. The strict anaerobes likeBifidobacteriumspp. (3 folds),Bacteroidesspp. (134 folds),Lactobacillusspp. (7 folds) and other selected obligate anaerobes likeClostridium perfringens(40 folds),Peptostreptococcusspp. (21 folds) increased in respect to their control population. The growth direction index (GDI) of anaerobic populations was positive and correlated with gas formation aptitude. The activities of CAT and SOD in the large intestinal epithelia decreased significantly (p < 0.05) and GSH/GSSG pool turned into oxidized state with higher MDA (p < 0.05) formation. Histological study revealed the necrotized epithelial layer with higher lymphocytes infiltration in lamina propia accompanied by reduction of acidic mucins secreting goblet cells. From this experiment, it can be hypothesized that high altitude induced hypoxia manipulated the bacterial imprint and damaged the epithelial barrier of the large intestine which may cause systemic infection.