Higuchi Shinya, Wu Rongqian, Zhou Mian, Ravikumar Thanjavur S, Wang Ping
Department of Surgery, North Shore University Hospital and Long Island Jewish Medical Center, Manhasset, New York 11030, USA.
J Surg Res. 2007 Jan;137(1):46-52. doi: 10.1016/j.jss.2006.04.019. Epub 2006 Nov 13.
The "double-hit" model of hemorrhage and sepsis mimics the critically ill patient admitted to the surgical intensive care unit. Although the protein expression of a cytochrome (CYP) P-450 isoform CYP1A2 is reduced in the late stage of sepsis, the effect of hemorrhage on CYP isoforms and the anti-inflammatory nuclear receptor peroxisome proliferator-activated receptor-gamma (PPAR-gamma) has not been investigated. We hypothesized that hemorrhage down-regulates CYP isoforms and PPAR-gamma in the liver, which plays an important role in producing tissue injury and proinflammatory responses after the subsequent sepsis (i.e., double-hit).
Male Sprague Dawley rats were divided into four groups. Animals in the double-hit group underwent hemorrhage (40 +/- 2 mmHg for 90 min) followed by fluid resuscitation. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) 20 h after hemorrhage, and the animals were sacrificed 4 h after CLP. Rats in the hemorrhage-alone group were sacrificed 20 h after the insult. Rats in the CLP-alone group were sacrificed 4 h after the onset of sepsis. Animals in the sham-operated group underwent neither hemorrhage nor CLP. The gene expression of P-450 isoforms (i.e., CYP1A2 and 2C11) and PPAR-gamma in the liver was determined using RT-PCR. Serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate, and proinflammatory cytokines (i.e., IL-6, TNF-alpha) were also assessed.
In the hemorrhage-alone group, hepatic mRNA expression of CYP1A2, CYP2C11, and PPAR-gamma was significantly down-regulated 20 h after the initial stress compared with sham-operated rats. Double-hit did not appear to further decrease CYP and PPAR-gamma gene expression. In contrast, serum levels of AST, ALT, lactate, IL-6, and TNF-alpha did not change significantly in either hemorrhaged or septic animals. Those organ injury indicators and cytokines, however, were significantly elevated after the double-hit of hemorrhage and sepsis.
Hepatic CYP1A2, CYP2C11, and PPAR-gamma were down-regulated after the initial stress (hemorrhage). These down-regulated CYPs and PPAR-gamma seem to work as important factors contributing to the progression of organ injury and proinflammatory responses after the second stress (CLP).
出血和脓毒症的“双重打击”模型模拟了入住外科重症监护病房的重症患者。尽管细胞色素（CYP）P - 450同工酶CYP1A2的蛋白质表达在脓毒症后期降低，但出血对CYP同工酶和抗炎核受体过氧化物酶体增殖物激活受体γ（PPAR - γ）的影响尚未得到研究。我们假设出血会下调肝脏中的CYP同工酶和PPAR - γ，这在随后的脓毒症（即双重打击）后产生组织损伤和促炎反应中起重要作用。
雄性Sprague Dawley大鼠分为四组。双重打击组的动物先经历出血（40±2 mmHg，持续90分钟），然后进行液体复苏。在出血20小时后通过盲肠结扎和穿刺（CLP）诱导多微生物脓毒症，在CLP后4小时处死动物。单纯出血组的大鼠在损伤后20小时处死。单纯CLP组的大鼠在脓毒症发作后4小时处死。假手术组的动物既不经历出血也不经历CLP。使用逆转录聚合酶链反应（RT - PCR）测定肝脏中P - 450同工酶（即CYP1A2和2C11）和PPAR - γ的基因表达。还评估了血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、乳酸和促炎细胞因子（即白细胞介素 - 6、肿瘤坏死因子 - α）的浓度。
与假手术组大鼠相比，单纯出血组在初始应激20小时后，肝脏中CYP1A2、CYP2C11和PPAR - γ的mRNA表达显著下调。双重打击似乎并未进一步降低CYP和PPAR - γ基因表达。相比之下，出血或脓毒症动物的血清AST、ALT、乳酸、白细胞介素 - 6和肿瘤坏死因子 - α水平均无显著变化。然而，在出血和脓毒症的双重打击后，这些器官损伤指标和细胞因子显著升高。
初始应激（出血）后肝脏中的CYP1A2、CYP2C11和PPAR - γ被下调。这些下调的CYP和PPAR - γ似乎是导致二次应激（CLP）后器官损伤进展和促炎反应的重要因素。
