Grosche Astrid, Freeman David E, Morton Alison J, Polyak Maximilian M R, Matyjaszek Sarah A
Island Whirl Equine Colic Research Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA. agrosche@.ufl.edu
Am J Vet Res. 2012 Jan;73(1):53-61. doi: 10.2460/ajvr.73.1.53.
To assess the effects of ischemia and reperfusion on indicators of oxidative stress, activation of eosinophils, and apoptosis in the large colonic mucosa of horses.
40 horses.
In 1 or two 20-cm-long segments of the pelvic flexure, ischemia was induced for 1 or 2 hours followed by no reperfusion or 30 minutes and 18 hours of reperfusion in anesthetized horses. Mucosal specimens were collected before (controls; n = 20 horses) and after each period of ischemia, and full-thickness tissue samples were collected after each period of reperfusion. Sections of colonic tissues were stained for histomorphometric analysis or assessment of eosinophil accumulation. Nitrotyrosine was identified immunohistochemically, and severity of apoptosis was determined via the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method.
Numbers of mucosal eosinophils were similar before induction of ischemia, after ischemia, and after ischemia-reperfusion. Eosinophil nitrotyrosine production increased significantly during ischemia and continued through 30 minutes of reperfusion; production was decreased at 18 hours of reperfusion but remained greater than that of the controls. In other leukocytes, nitrotyrosine generation peaked at 1 hour of ischemia and again at 18 hours of reperfusion. Compared with control findings, epithelial apoptosis increased gradually at 1 through 2 hours of ischemia with no further progression after reperfusion.
Results suggested that resident eosinophils in the large colon of horses react to mucosal injury from ischemia and reperfusion and may undergo oxidative stress under those conditions. Epithelial apoptosis could contribute to tissue damage.
评估缺血和再灌注对马的大结肠黏膜氧化应激指标、嗜酸性粒细胞活化及细胞凋亡的影响。
40匹马。
在麻醉的马的盆腔曲的1段或2段20厘米长的肠段中诱导缺血1或2小时，随后不进行再灌注或分别进行30分钟和18小时的再灌注。在缺血各阶段之前（对照组；n = 20匹马）以及之后采集黏膜标本，并在再灌注各阶段之后采集全层组织样本。对结肠组织切片进行染色，用于组织形态计量分析或嗜酸性粒细胞积聚评估。通过免疫组织化学鉴定硝基酪氨酸，并通过末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记法确定细胞凋亡的严重程度。
缺血诱导前、缺血后以及缺血再灌注后黏膜嗜酸性粒细胞数量相似。嗜酸性粒细胞硝基酪氨酸生成在缺血期间显著增加，并持续至再灌注30分钟；在再灌注18小时时生成减少，但仍高于对照组。在其他白细胞中，硝基酪氨酸生成在缺血1小时时达到峰值，在再灌注18小时时再次达到峰值。与对照结果相比，上皮细胞凋亡在缺血1至2小时时逐渐增加，再灌注后无进一步进展。
结果表明，马的大结肠中的固有嗜酸性粒细胞对缺血和再灌注引起的黏膜损伤有反应，并且在这些条件下可能经历氧化应激。上皮细胞凋亡可能导致组织损伤。
