EVIDENCE FOR PEPTIDOGLYCAN ABSORPTION IN RATS WITH EXPERIMENTAL SMALL-BOWEL BACTERIAL OVERGROWTH
EVIDENCE FOR PEPTIDOGLYCAN ABSORPTION IN RATS WITH EXPERIMENTAL SMALL-BOWEL BACTERIAL OVERGROWTH
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DOI：
10.1128/iai.59.2.555-562.1991
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发表时间：
1991-02-01
影响因子：
3.1
通讯作者：
SARTOR, RB
中科院分区：
文献类型：
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作者：
LICHTMAN, SN;KEKU, J;SARTOR, RB
手术创造空肠自填盲环（SFBL）导致小肠细菌过度生长，这与易感Lewis和Wistar大鼠菌株的肝胆炎症有关。由于当小肠厌氧菌浓度增加4至6 log10单位/ ml且肝脏细菌培养呈阴性时，就会发生肝损伤，因此我们假设炎症是由循环内细菌对炎性细胞壁聚合物的吸收引起的。为了证明细菌细胞壁聚合物的吸收，我们测量了腔内注射后血浆和肝脏中免疫反应性肽聚糖多糖（PG- ps）的水平，以及抗PG抗体的水平，作为内源性PG吸收和/或积累的间接测量。从A组链球菌中纯化的PG- ps在腔内注射后通过酶联免疫吸附法检测血浆中；与假手术大鼠和甲硝唑治疗的SFBL大鼠相比，SFBL大鼠血浆和肝脏摄取甲硝唑明显增加（P < 0.025）。假手术大鼠血浆总免疫球蛋白A （IgA）、IgG和IgM水平与自掏空盲环或SFBL大鼠无显著差异，但SFBL大鼠血浆抗pg IgA （P < 0.05）、IgG和IgM水平升高（P < 0.01）。甲硝唑和四环素抑制pg抗体升高，庆大霉素和多粘菌素B抑制pg抗体升高。在SFBL大鼠中，血浆中的抗脂质A、抗大豆蛋白和抗chow抗体并没有持续增加，这表明缺乏对腔内抗原的普遍抗体反应。这些数据表明，来自正常菌群细菌的PG从肠腔吸收，粘膜损伤和/或肠道内PG浓度增加，如小肠细菌过度生长引起的，导致潜在炎症性细菌聚合物的吸收增强。
Surgical creation of jejunal self-filling blind loops (SFBL) causes small bowel bacterial overgrowth which is associated with hepatobiliary inflammation in the susceptible Lewis and Wistar rat strains.. Since hepatic injury occurs when small bowel anaerobic bacterial concentrations are increased 4 to 6 log10 units per ml and hepatic bacterial cultures are negative, we postulate that the inflammation is caused by absorption of phlogistic cell wall polymers originating from bacteria within the loop. To demonstrate absorption of bacterial cell wall polymers, we measured plasma and hepatic levels of immunoreactive peptidoglycan-polysaccharide (PG-PS) following intraluminal injection as well as anti-PG antibodies as an indirect measure of absorption and/or accumulation of endogenous PG. PG-PS purified from group A streptococci was detected in plasma by enzyme-linked immunosorbent assay after intraluminal injection; rats with SFBL showed significantly more uptake into plasma and the liver than sham-operated rats or SFBL rats which were treated with metronidazole (P < 0.025). Total plasma immunoglobulin A (IgA), IgG, and IgM levels did not differ among sham-operated rats and those with self-emptying blind loops or SFBL, but plasma anti-PG IgA (P < 0.05), IgG, and IgM (P < 0.01) levels were increased in rats with SFBL. Metronidazole and tetracycline prevented the elevation of anti-PG antibody, but gentamicin and polymyxin B did not. Anti-lipid A, anti-soy protein, and anti-chow antibodies in plasma were not consistently increased in rats with SFBL indicating the lack of a generalized antibody response to luminal antigens. These data suggest that PG from normal flora bacteria is absorbed from the intestinal lumen and that mucosal injury and/or increased luminal concentrations of PG, such as those induced by small bowel bacterial overgrowth, lead to enhanced absorption of potentially inflammatory bacterial polymers.