Mella Juan Rodolfo, Chiswick Evan L, King Elizabeth, Remick Daniel G
*Department of Pathology and Laboratory Medicine, Boston University School of Medicine; and †Department of Surgery, Boston University Medical Center, Boston, Massachusetts.
Shock. 2014 Oct;42(4):337-42. doi: 10.1097/SHK.0000000000000222.
Considerable breakthroughs in the field of sepsis have been made using animal models. Sepsis exhibits a wide array of derangements that may be evaluated in the blood, including the release of proinflammatory and anti-inflammatory cytokines. The Shock journal adheres to the ARRIVE guidelines regarding reporting in vivo results to allow reproducibility of data findings. It is generally assumed that blood cytokine concentrations collected from typical sampling sites will be similar, but there are no data validating that this is true. The main purpose of the present study was to determine if the location of blood sampling results in cytokine concentration differences following inflammatory insults.
Two different models of acute inflammation were studied. Adult, female ICR (Institute of Cancer Research) mice were injected with Escherichia coli lipopolysaccharide (n = 28) or subjected to cecal ligation and puncture (n = 16). They were killed at early time points following these inflammatory challenges for the collection of blood from the facial vein, retro-orbital sinus, and heart. Additional samples were collected in EDTA and heparin. Plasma cytokines from the same mouse were collected from each sampling site and evaluated by enzyme-linked immunosorbent assay. Clinical chemical parameters including plasma blood urea nitrogen and total protein were also analyzed.
Regardless of model, time of collection, or cytokine measured, cytokine values from heart blood were higher than facial vein values from the same mouse. Interleukin (IL-6) collected from the heart relative to the facial vein demonstrated elevated concentrations following injection of lipopolysaccharide. In a similar manner, higher concentrations of IL-6, macrophage inflammatory protein 2, IL-10, and IL-1 receptor antagonist were found in cardiac puncture samples compared with other sampling sites 24 h after sepsis induced by cecal ligation and puncture. Similar differences were not seen when comparing blood urea nitrogen and total protein values from the two different sites. Using plasma IL-6 collected from the heart would incorrectly stratify predicted-to-live mice into the predicted-to-die category. Therefore, a simple linear regression model was developed to correctly restratify mice to their predicted fate. These data demonstrate that proinflammatory and anti-inflammatory cytokine concentrations are dramatically elevated when drawn centrally from the heart compared with collection from peripheral locations such as the facial vein. It is critical for publications to document the sampling location when evaluating plasma cytokines and attempting to compare studies.
利用动物模型在脓毒症领域取得了重大突破。脓毒症表现出一系列可在血液中评估的紊乱情况，包括促炎和抗炎细胞因子的释放。《休克》杂志遵循关于报告体内结果的ARRIVE指南，以确保数据结果的可重复性。一般认为，从典型采样部位采集的血液细胞因子浓度会相似，但尚无数据证实这一点。本研究的主要目的是确定采血部位是否会导致炎症刺激后细胞因子浓度的差异。
研究了两种不同的急性炎症模型。成年雌性ICR（癌症研究所）小鼠注射大肠杆菌脂多糖（n = 28）或进行盲肠结扎和穿刺（n = 16）。在这些炎症刺激后的早期时间点将它们处死，以便从面静脉、眶后窦和心脏采集血液。另外的样本收集在乙二胺四乙酸（EDTA）和肝素中。从同一小鼠的每个采样部位收集血浆细胞因子，并通过酶联免疫吸附测定法进行评估。还分析了包括血浆尿素氮和总蛋白在内的临床化学参数。
无论模型、采集时间或所测细胞因子如何，同一小鼠心脏血液中的细胞因子值均高于面静脉中的值。注射脂多糖后，从心脏相对于面静脉采集的白细胞介素（IL-6）浓度升高。以类似方式，在盲肠结扎和穿刺诱导脓毒症24小时后，与其他采样部位相比，心脏穿刺样本中发现更高浓度的IL-6、巨噬细胞炎性蛋白2、IL-10和IL-1受体拮抗剂。比较两个不同部位的尿素氮和总蛋白值时未发现类似差异。使用从心脏采集的血浆IL-6会将预测存活的小鼠错误地归类为预测死亡的类别。因此，开发了一个简单的线性回归模型来将小鼠正确重新分类到其预测的命运类别。这些数据表明，与从外周部位（如面静脉）采集相比，从心脏中央采集时促炎和抗炎细胞因子浓度显著升高。在评估血浆细胞因子并试图比较研究时，出版物记录采样部位至关重要。
