Lin M T, Saito H, Fukushima R, Inaba T, Fukatsu K, Inoue T, Furukawa S, Han I, Muto T
Department of Surgery, Faculty of Medicine, University of Tokyo, Japan.
Ann Surg. 1996 Jan;223(1):84-93. doi: 10.1097/00000658-199601000-00012.
The authors' aim was to investigate whether antecedent nutritional routes influence immune responses after surgical insult.
Total parenteral nutrition (TPN) may influence host responses to infection. To the best of the authors' knowledge, however, no study has focused on the mechanisms underlying the influence of nutritional route on local, systemic, and remote organ (lung) responses after surgical insult.
Sixty-eight rats were divided into TPN and total enteral nutrition (TEN) groups. The two groups received identical nutrients for 7 days and were then challenged intraperitoneally with 3 x 10(8) Escherichia coli. In the first experiment, the rats were observed for survival. In the second experiment, the rats were killed before (0 hours) challenge or 2 or 6 hours after challenge. Peritoneal exudative cells (PEC) and bronchoalveolar cells (BALC) were harvested and cultured in vitro. Colony-forming units of bacteria in the peritoneal lavage fluid (PLF) were determined. Tumor necrosis factor (TNF), interleukin-1 alpha (IL-1 alpha), interferon-gamma (IFN-gamma) levels in serum, PLF, bronchoalveolar lavage fluid (BALF), and cell culture supernatants were measured.
The 48-hour survival rate was higher in TEN than in TPN rats. Local immunity was depressed in the TPN group. Bacterial colony counts in PLF were significantly higher in the TPN group than in the TEN group after challenge. The number of PECs was significantly lower, and at 2 hours, local cytokine (TNF and IL-1 alpha) responses were diminished in the TPN group compared with the TEN group at 2 hours. The number of PECs showed a significant positive correlation with levels of local cytokines in the TEN group but not in the TPN group. Elevation of local IFN-gamma was significant from 0 to 6 hours in the TEN group but not in the TPN group. In vitro production of TNF by PEC was impaired in the TPN rats before challenge. Remote organ (lung) responses were suppressed in the TPN group. The number of BALCs and the TNF levels in BALF declined significantly between 0 and 2 hours in the TEN group but not in the TPN group. Interferon-gamma levels in BALF were higher in the TEN group than in the TPN group at 2 hours. Systemic cytokine responses were disturbed in the TPN group. Production of systemic TNF was greater, but the IFN-gamma response was diminished in the TPN group compared with the TEN group after intraperitoneal bacterial challenge.
Local, systemic, and remote organ (lung) immune responses to intraperitoneal bacterial challenge are suppressed in TPN-treated animals, leading to poor survival after challenge. Enteral nutrition before surgical insult may enhance host immune responses after the insult as compared to parenteral nutrition.
作者旨在研究术前营养途径是否会影响手术创伤后的免疫反应。
全肠外营养（TPN）可能会影响宿主对感染的反应。然而，据作者所知，尚无研究关注营养途径对手术创伤后局部、全身及远处器官（肺）反应影响的潜在机制。
68只大鼠被分为TPN组和全肠内营养（TEN）组。两组接受相同的营养物质7天，然后腹腔注射3×10⁸大肠杆菌进行刺激。在第一个实验中，观察大鼠的存活情况。在第二个实验中，在刺激前（0小时）或刺激后2或6小时处死大鼠。收集腹膜渗出细胞（PEC）和支气管肺泡细胞（BALC）并进行体外培养。测定腹腔灌洗液（PLF）中的细菌菌落形成单位。测量血清、PLF、支气管肺泡灌洗液（BALF）和细胞培养上清液中的肿瘤坏死因子（TNF）、白细胞介素-1α（IL-1α）、干扰素-γ（IFN-γ）水平。
TEN组大鼠的48小时存活率高于TPN组。TPN组的局部免疫受到抑制。刺激后，TPN组PLF中的细菌菌落计数显著高于TEN组。TPN组的PEC数量显著降低，且在2小时时，与TEN组相比，TPN组的局部细胞因子（TNF和IL-1α）反应减弱。在TEN组中，PEC数量与局部细胞因子水平呈显著正相关，而在TPN组中则无此相关性。在TEN组中，从0至6小时局部IFN-γ升高显著，而在TPN组中则不然。在刺激前，TPN组大鼠的PEC体外产生TNF的能力受损。TPN组的远处器官（肺）反应受到抑制。在TEN组中，0至2小时BALC数量和BALF中的TNF水平显著下降，而TPN组则无此变化。在2小时时，TEN组BALF中的干扰素-γ水平高于TPN组。TPN组的全身细胞因子反应受到干扰。腹腔内细菌刺激后，与TEN组相比，TPN组的全身TNF产生量更大，但IFN-γ反应减弱。
在接受TPN治疗的动物中，对腹腔内细菌刺激的局部、全身及远处器官（肺）免疫反应受到抑制，导致刺激后存活率较低。与肠外营养相比，手术创伤前的肠内营养可能会增强创伤后宿主的免疫反应。
