Tadros Elizabeth M, Frank Nicholas, Donnell Robert L
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
Am J Vet Res. 2013 Jul;74(7):1010-9. doi: 10.2460/ajvr.74.7.1010.
To test the hypothesis that inflammatory responses to endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS). Animals-6 healthy horses and 6 horses with EMS.
Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline data were obtained 30 minutes before each infusion. After infusion, a physical examination was performed hourly for 9 hours and at 15 and 21 hours; a whole blood sample was collected at 30, 60, 90, 120, 180, and 240 minutes for assessment of inflammatory cytokine gene expression. Liver biopsy was performed between 240 and 360 minutes after infusion. Results-Following lipopolysaccharide infusion in healthy horses and horses with EMS, mean rectal temperature, heart rate, and respiratory rate increased, compared with baseline findings, as did whole blood gene expression of interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α. The magnitude of blood cytokine responses did not differ between groups, but increased expression of IL-6, IL-8, IL-10, and tumor necrosis factor-α persisted for longer periods in EMS-affected horses. Lipopolysaccharide infusion increased liver tissue gene expressions of IL-6 in healthy horses and IL-8 in both healthy and EMS-affected horses, but these gene expressions did not differ between groups.
Results supported the hypothesis that EMS affects horses' inflammatory responses to endotoxin by prolonging cytokine expression in circulating leukocytes. These findings are relevant to the association between obesity and laminitis in horses with EMS.
检验健康马匹与患有马代谢综合征（EMS）的马匹对内毒素血症的炎症反应是否存在差异。动物——6匹健康马匹和6匹患有EMS的马匹。
每匹马随机接受静脉输注脂多糖（20 ng/kg[溶于60 mL无菌生理盐水{0.9% NaCl}溶液中]）或生理盐水溶液，在7天的洗脱期后接受另一种处理。在每次输注前30分钟获取基线数据。输注后，每小时进行一次体格检查，持续9小时，并在15和21小时进行；在30、60、90、120、180和240分钟采集全血样本，用于评估炎性细胞因子基因表达。在输注后240至360分钟之间进行肝活检。结果——在健康马匹和患有EMS的马匹中输注脂多糖后，与基线结果相比，平均直肠温度、心率和呼吸频率均升高，白细胞介素（IL）-1β、IL-6、IL-8、IL-10和肿瘤坏死因子-α的全血基因表达也升高。两组之间血液细胞因子反应的幅度没有差异，但在受EMS影响的马匹中，IL-6、IL-8、IL-10和肿瘤坏死因子-α的表达持续升高的时间更长。脂多糖输注增加了健康马匹肝脏组织中IL-6的基因表达，以及健康和受EMS影响马匹中IL-8的基因表达，但这些基因表达在两组之间没有差异。
结果支持以下假设，即EMS通过延长循环白细胞中的细胞因子表达来影响马匹对内毒素的炎症反应。这些发现与患有EMS的马匹肥胖与蹄叶炎之间的关联有关。
