Khiabani Kayvan T, Bellister Seth A, Skaggs Sarah S, Stephenson Linda L, Nataraj Chandra, Wang Wei Z, Zamboni William A
Microsurgery and Hyperbaric Laboratory, Division of Plastic Surgery, University of Nevada School of Medicine, Las Vegas, Nevada 89102-2227, USA.
J Surg Res. 2008 Nov;150(1):11-6. doi: 10.1016/j.jss.2007.12.780. Epub 2008 Jan 22.
Hyperbaric oxygen (HBO) inhibits ischemia reperfusion (IR) -induced neutrophil adhesion to endothelium through an unknown mechanism. This study evaluates the effect of HBO on IR-stimulated neutrophil adhesion and polarization of expressed CD18 adhesion molecules using a novel in vitro adhesion assay and confocal microscopy.
Neutrophils from normal animals were isolated from whole blood and incubated with plasma from rat gracilis muscle flaps on coverslips pretreated with ICAM. Percent adherence to ICAM and CD18 polarization was evaluated in the following five groups: (1) Nonischemic control, n = 15; (2) 4 h ischemia (IR, n = 15); (3) 4 h ischemia with HBO treatment (100% oxygen at 2.5 atmospheres absolute (IR + HBO, n = 15)); (4) 4 h ischemia with 100% oxygen at room temperature and pressure (RTP) (IR + normobaric hyperoxia, n = 5); and (5) 4 h ischemia with 8% oxygen at 2.5 atmospheres absolute (IR + hyperbaric normoxia, n = 5). Direct HBO treatment of neutrophils was also evaluated.
Neutrophils exposed to IR plasma showed a significant increase in percent adherent (0.8 +/- 0.1% versus 16.7 +/- 2.2%, P < 0.05) and polarized cells (6.2 +/- 1.7% versus 43.9 +/- 12.2%, P < 0.05) compared to controls. Hyperbaric oxygen significantly reduced the adhesion and polarization to 1.6 +/- 0.3 and 4.1 +/- 2.5%, respectively (P = < 0.05). Normobaric hyperoxia and hyperbaric normoxia did not affect neutrophil adherence or CD18 polarization following IR. Direct HBO treatment of neutrophils did not change the percent of polarized cells in IR.
Hyperbaric oxygen inhibits IR-induced neutrophil adhesion by blocking CD18 surface polarization and requires plasma exposure to HBO. Treatment with oxygen or pressure alone is not effective.
高压氧（HBO）通过未知机制抑制缺血再灌注（IR）诱导的中性粒细胞与内皮细胞的黏附。本研究使用一种新型体外黏附试验和共聚焦显微镜评估HBO对IR刺激的中性粒细胞黏附以及表达的CD18黏附分子极化的影响。
从正常动物的全血中分离出中性粒细胞，并将其与大鼠股薄肌皮瓣的血浆在经细胞间黏附分子（ICAM）预处理的盖玻片上孵育。在以下五组中评估对ICAM的黏附百分比和CD18极化情况：（1）非缺血对照组，n = 15；（2）4小时缺血（IR组，n = 15）；（3）4小时缺血并接受HBO治疗（2.5个绝对大气压下的100%氧气，IR + HBO组，n = 15）；（4）4小时缺血并在室温和常压下给予100%氧气（IR + 常压高氧组，n = 5）；（5）4小时缺血并在2.5个绝对大气压下给予8%氧气（IR + 高压常氧组，n = 5）。还评估了对中性粒细胞的直接HBO治疗。
与对照组相比，暴露于IR血浆的中性粒细胞黏附百分比（0.8 ± 0.1% 对16.7 ± 2.2%，P < 0.05）和极化细胞百分比（6.2 ± 1.7% 对43.9 ± 12.2%，P < 0.05）显著增加。高压氧显著降低黏附和极化，分别降至1.6 ± 0.3%和4.1 ± 2.5%（P < 0.05）。常压高氧和高压常氧对IR后的中性粒细胞黏附或CD18极化无影响。对中性粒细胞的直接HBO治疗未改变IR中极化细胞的百分比。
高压氧通过阻断CD18表面极化抑制IR诱导的中性粒细胞黏附，且需要血浆暴露于HBO。单独的氧气或压力治疗无效。
