Effects of three intravenous lipid emulsions on the survival and mononuclear phagocyte function of septic rats

The immunosuppressive effects of intravenous lipid emulsions are a matter of great concern and debate. In a rat model of gram-negative bacteremia, we assessed whether the use of three intravenous lipid emulsions with different triacylglycerol compositions could influence mortality, bacterial clearance, and prostaglandin E(2) (PGE(2)) levels and compared these groups with groups of orally fed rats and rats that received a small amount of calories in form of glucose without enteral feeding (starvation).RATS WERE ASSIGNED TO ONE OF FIVE GROUPS: group 1 (control, n = 15) received rodent chow ad libitum and saline infusion; group 2 (starvation group, n = 12) had no access to chow and received an infusion of 5% glucose; group 3 (n = 17) received total parenteral nutrition (TPN) with long-chain triacylglycerols; group 4 (n = 12) received TPN with medium- and long-chain triacylglycerols; and group 5 (n = 15) received TPN with its emulsion based on olive oil. Animals received isonitrogenous and isocaloric TPN. After 2 d of TPN, a dose of 10(8) colony-forming units of Escherichia coli was introduced via the venous catheter; 2 d later the animals were killed. Blood, spleen, liver, and lungs were cultured. Circulating levels of PGE(2) were measured.Bacterial growth in the liver and lungs were significantly higher in groups 3 and 4 than in group 1, with no differences among the other groups. Rates of bacteremia were significantly higher in groups 3 and 4 than in group 1, with no differences among the other groups. Plasma levels of PGE(2) did not differ, and mortality was unaffected.Bacterial clearance clearly was preserved in orally fed, control rats when compared with rats on TPN with long-chain triacylglycerols or medium- plus long-chain triacylglycerols. However, the use of a lipid emulsion enriched intravenously with oleic acid was a valid way of reducing this disturbance, although plasma levels of PGE(2) and survival were not modified.     

Effects of parenteral infusion with medium-chain triglycerides and safflower oil emulsions on hepatic lipids, plasma amino acids and inflammatory mediators in septic rats

This study was designed to investigate the effects of preinfusion with total parenteral nutrition (TPN) using medium-chain triglycerides (MCT) versus safflower oil (SO) emulsion as fat sources on hepatic lipids, plasma amino acid profiles, and inflammatory-related mediators in septic rats. Normal rats, with internal jugular catheters, were divided into two groups and received TPN. TPN provided 300kcal/kg/day with 40% of the non-protein energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was made of SO or a mixture of MCT and soybean oil (9:1) (MO). After receiving TPN for 6 days, each group of rats was further divided into control and sepsis subgroups. Sepsis was induced by cecal ligation and puncture, whereas control rats received sham operation. All rats were classified into four groups as follows: MCT control group (MOC, n= 8), MCT sepsis group (MOS, n= 8), safflower oil control group (SOC, n= 8), and safflower oil sepsis group (SOS, n= 11). The results of the study demonstrated that the MOS group had lower hepatic lipids than did the SOS group. Plasma leucine and isoleucine levels were significantly lower in the SOS than in the SOC group, but no differences in these two amino acids were observed between the MOC and MOS groups. Plasma arginine levels were significantly lower in septic groups than in those without sepsis despite whether MCT or safflower oil was infused. Plasma glutamine and alanine levels, however, did not differ between septic and non-septic groups either in the SO or MO groups. No differences in interleukin-1b, interleukin-6, tumor necrosis factor-alpha, and leukotriene B(4)concentrations in peritoneal lavage fluid were observed between the two septic groups. These results suggest that catabolic reaction is septic rats preinfused MCT is not as obvious as those preinfused safflower oil. Compared with safflower oil, TPN with MCT administration has better effects on reducing sepsis-induced liver fat deposition. Preinfusion with MCT before sepsis, however, had no effect on inflammatory-related cytokines or leukotriene in peritoneal lavage fluid. In addition, plasma arginine appears to be a more sensitive indicator than glutamine for septic insult.     

Influences of an infusion of lipid emulsion on phagocytotic activity of cultured Kupffer's cells in septic rats

An experimental study was undertaken to study the influences of an infusion of lipid emulsion on phagocytosis of Kupffer's cells in septic rats. Sepsis was induced in 13 rats by ligating the cecum. Five of them received glucose as the sole nonprotein calorie (septic-glucose group), four of the rats received 25% of the nonprotein calorie with lipid emulsion, Intralipid (septic-lipid group), and the remaining four rats did not receive any intravenous solution and were allowed access to water (septic-fasted group). Another four rats which received neither intravenous solution nor ligation of the cecum served as the control group. The intravenous infusion was carried out for 72 hr. The phagocytotic activity of Kupffer's cells was determined by the ability to engulf latex particles with a size of 1.09 micron, in vitro. The phagocytotic activity was enhanced by the presence of sepsis but it was inhibited by starvation. The difference in the phagocytotic activity between the septic-glucose group and the septic-lipid group was not significant. These results suggest that, insofar as an in vitro study is concerned, a 72-hr infusion of lipid emulsion at a rate of 25% of the total nonprotein calorie does not influence the phagocytotic activity of cultured Kupffer's cell obtained from septic rats.     

Clinical and metabolic effects of two lipid emulsions on the parenteral nutrition of septic patients

OBJECTIVE: We compared the metabolic and clinical effects of two lipid emulsions, long-chain triacylglycerols (LCT) and a mixture of medium- and long-chain triacylglycerols (MCT/LCT), in septic patients. METHODS: Both groups received total parenteral nutrition (TPN) with a solution enriched with branched-chain amino acids (BCAA). Seventy-two septic patients received TPN with MCT/LCT (group 1) or LCT (group 2). Before starting TPN (basal) and 10 d after (final), various parameters were evaluated. RESULTS: Twenty-six subjects in each group completed the study. Both groups showed an increase in cholestasis enzymes, with no significant changes in lipid parameters. The rise of retinol-binding protein and the recovery of nitrogen balance were significantly greater in group 1. A multivariate analysis of nutritional markers and catabolic parameters showed a better evolution in group 1 (P = 0.002). The MCT/LCT group exhibited a significant increase of insulin levels. Overall mortality and length of stay in the intensive care unit were not affected by the lipid emulsion. CONCLUSIONS: In septic patients who received TPN with a solution enriched with BCAAs, the use of an emulsion containing MCT provided them with a greater recovery of their nutrition status than the traditional LCT formula, without influencing the outcome.     

肠外营养中脂肪乳剂对红细胞变形性的影响

利用大鼠胃肠外营养（PN）模型观察长链脂肪乳剂（LCT），中链／长链脂肪乳剂（MCT／TCT），以及不含脂肪乳剂对红细胞变形性的影响。PN总热量为300kcal·kg-1·d-1，非蛋白热卡：氮为182：1，LCT组、MCT／LCT组分别由10％Intralipid和10％Lipofundin提供30％的非蛋白热卡。7天后，分析红细胞膜磷脂脂肪酸组成和用激光衍射法测定红细胞变形性。结果发现，尽管红细胞膜磷腊脂肪酸组成发生改变，由于脂肪酸饱和度变化不大，红细胞变形性无改变。     

Hypocaloric lipid emulsions and amino acid metabolism in injured rats

The present study was designed to determine the degree and mechanism by which administration of medium-chain triglyceride emulsions spare body protein after injury. Forty male rats underwent venous catheterization and received nonsterile bilateral femur fractures. All rats received 2.5 g/day amino acids and either no additional calories (group I) or 20 kcal/day of either glucose (group II), a long-chain triglyceride emulsion (group III), a medium-chain triglyceride emulsion (group IV), or a structured lipid emulsion composed of 40% sunflower oil and 60% medium-chain triglycerides (group V). The diets were administered for 3 days, and rates of plasma leucine flux, oxidation, and incorporation into protein as well as tissue protein synthetic rates in liver and muscle were measured using the constant infusion of L-[1-14C]leucine. Results demonstrated that the administration of glucose or various lipid emulsions improved cumulative nitrogen balance significantly when compared to a diet containing amino acids alone. In addition, the administration of glucose or lipid emulsions significantly stimulated protein synthesis in liver and muscle. Moreover, a structured lipid emulsion of medium- and long-chain fatty acids produced significant increases in liver protein synthesis greater than that observed with either glucose or long-chain triglyceride emulsions. We conclude that added energy as fat or glucose reduces net protein catabolism and improves tissue protein synthesis in these injures rats and that lipid emulsions are as effective as dextrose. A structured triglyceride emulsion synthesized from medium- and long-chain fatty acids appears to better support hepatic protein synthesis.     

职业性铅暴露对促炎细胞因子和血管生成因子水平的影响

目的探讨长期职业性铅暴露对促炎细胞因子和促血管生成因子水平的影响。方法选择居住在同一地区200名接触铅工作的男性为暴露组,年龄相当的无铅接触史137名男性为对照组。受试者清晨空腹肘部静脉血,检测血清促炎细胞因子[白细胞介素1β(IL-1β)、白细胞介素-6(IL-6)、巨噬细胞炎性蛋白1α(MIP-1α)、肿瘤坏死因子α(TNF-α)]、血管生成因子[血管内皮生长因子(VEGF)、可溶性血管内皮生长因子受体-1(sVEGFR-1)、可溶性血管生成素受体2(Stie-2)、成纤维细胞生长因子(FGF-basic)]水平。结果长期接触铅的工人组促炎细胞因子IL-1β、IL-6和TNF-α水平高于对照组(P值均<0.001),血管生成因子sVEGFR-1、FGF-basic水平显著高于对照组(P值均<0.001)。在长期铅暴露组中,促炎细胞因子(IL-1a、IL-6、TNF-a)水平与血管生成因子(VEGF、FGF-basic、sVEGFR-1、Stie-2)呈正相关(r=0.31~0.62,P值均<0.05)。结论长期职业性铅暴露可导致促炎细胞因子和血管生成因子浓度升高,且二者具有显著相关性。     

Effect of various lipid emulsions on total parenteral nutrition-induced hepatosteatosis in rats

The effect of various lipid emulsions on the development of fatty liver during total parenteral nutrition (TPN) was investigated in rats given TPN for 7 days. Medium-chain triglycerides (MCT), long-chain triglycerides (LCT), chemically defined triglycerides (CDT; structured lipid with a high purity of 94.3%), and a mixture of MCT and LCT (MIX) were prepared as the lipid emulsions. TPN provided 350 kcal/kg/day, with a nonprotein calorie/nitrogen ratio of 160. The TPN-1 group received 10% nonprotein calories and the TPN-2 group received 30% nonprotein calories. MCT TPN was found to have some disadvantages, especially with regard to nitrogen balance and plasma albumin levels. Total cholesterol and phospholipids tended to be high in the MCT TPN group. The hepatic lipid content was higher in the lipid-free TPN and the MCT TPN groups, and lower in the CDT and LCT TPN groups. Histologically, the livers of the MIX, CDT, and LCT TPN groups showed less fatty change than those of the FREE and MCT groups.     

Pharmacological concentrations of lipid emulsions inhibit interleukin-2-dependent lymphocyte responses in vitro

Most immunological functions are accomplished by means of interactions between mediator molecules (cytokines or lymphokines) and their specific receptors on the lymphocyte surface. One particular lymphokine, Interleukin-2 (IL-2) is central to the generation of most immune responses including those with antitumor activity. Prompted by two clinical trials which have suggested distinct but apparently opposite effects of lipid emulsions on the production of and lymphocyte responses to IL-2 we have examined the effects of pharmacological concentrations of three lipid emulsions currently in clinical use on IL-2 related interactions in vitro. Mitogen-stimulated and IL-2 activated human lymphocyte proliferation were both inhibited in a dose-dependent manner in the presence of all three lipid emulsions although the effects were less marked with the solution in which 50% of the calories are present as medium-chain triglycerides (MCT) rather than long-chain triglycerides (LCT). Similarly the LCT, but less so the MCT-containing solutions inhibited the generation of cytotoxic lymphokine-activated killer cells. These solutions did not inhibit the proliferation of cell lines which are not growth-factor dependent but did inhibit the growth of an IL-2-dependent cell line. We conclude that lipid emulsions can upset IL-2-dependent lymphocyte responses. These observations may lead to parenteral feeding regimens which are less immunocompromising for the tumor-bearing patient.     

冷应激对大鼠激素与T淋巴细胞因子的影响

摘要:目的　探讨冷应激对大鼠外周血应激激素及T淋巴细胞因子的影响。方法　将230只SD大鼠分为20℃、4℃、-12℃ 3个环境温度组,每个温度组分非刺激、细菌脂多糖刺激、刀豆素-A刺激亚组,每亚组分1、12、24、48 h 4个时间点观察组;ELISA测定血浆促肾上腺皮质激素,肾上腺素,血管紧张素-2,白介素-2,干扰素-γ,白介素-4和白介素-10。结果　与20℃比较,大鼠4℃和-12℃冷应激血浆促肾上腺皮质激素（1 h,24.48±1.58比51.37±32.32和52.95±3.41;12 h,35.62±5.46比58.12±30.86和73.26±7.14）和肾上腺素（1 h,41.12±2.59比96.45±32.27和110.87±4.66;12 h,73.99±24.28比127.34±77.43和126.36±31.48）、大鼠-12℃冷应激血浆血管紧张素-2（1 h:118.84±31.41比437.13±71.72;12 h,318.08±93.44比440.72±69.43;24 h,247.11±97.79比620.83±67.45;48 h,171.99±67.72比556.38±94.62）以及大鼠冷应激血浆白介素-10（4℃、1 h,21.14±5.27比53.84±25.26;12 h,38.78±14.96比70.02±34.41;24 h,35.65±4.24比57.32±20.70;48 h,37.39±12.31比65.40±32.11;-12℃、1 h,比64.89±13.01,12 h,比68.33±7.31）水平显著升高（P＜0.05）、脂多糖和刀豆素-A刺激机体未改变这种趋势。与20℃比较,血浆IL-2水平在脂多糖刺激下-12℃（48 h,938.18±193.11比675.65±88.14）和刀豆素-A刺激下4℃（1～ 48 h,786.67±134.58比462.34±102.42;1014.07±164.34比472.70±83.88;1194.69±152.03比392.66±41.43;991.56±225.16比501.89±46.65）和-12℃（24 h,比874.58±143.38;48 h比640.24±99.24）、血浆IL-4水平在4℃（12 h,115.58±43.14比62.36±11.94;24 h,90.76±31.85比56.66±20.16;48 h,93.69±37.56比68.09±12.59）和-12℃（12 h,比73.73±11.16）、脂多糖刺激时IL-4水平在4℃（24 h,110.49±51.58比60.13±23.05）以及刀豆素-A刺激时IL-4水平在4℃（1 h,58.25±10.00比32.47±10.43;12 h,125.45±56.12比53.22±9.04;24 h,109.36±15.22比37.93±15.21）和-12℃（12 h,比70.36±9.79）、血浆IFN-γ水平脂多糖刺激时在4℃（12 h,1751.66±618.91比1483.62±390.59）和-12℃（48 h,1829.49±414.15比1184.42±461.01）以及刀豆素-A刺激时在4℃（24 h,1738.92±192.44比1106.13±324.29）显著降低（P＜0.05）。结论　气温骤降可致大鼠应激激素升高以及适应性免疫功能受损。     

Effects of structurally different lipid emulsions on human neutrophil migration

AIM: To test the hypothesis that structurally different lipid emulsions have distinct immunomodulatory properties, we analysed neutrophil migration in the presence of various lipid emulsions. METHOD: Neutrophils of 8 volunteers were pre-incubated in medium or physiological 2.5 mM emulsions containing long-chain (LCT), medium-chain (MCT), mixed LCT/MCT, alpha -tocopherol-enriched LCT/MCT (LCT/MCT-E) or structured triglycerides (SL). Thereafter, the cells were put on top of 3 microm-pore-sized cell culture filters and incubated for one hour in the presence or absence of a chemo-attractant. Neutrophil migration was measured as the percentage of cells that had passed the filter in the presence (chemotaxis) or absence (random migration) of a chemotactic factor. RESULTS: Compared to lipid-free incubation (19+/-1%) random neutrophil migration significantly decreased with LCT/MCT (11+/-2%), LCT/MCT-E (12+/-2) and MCT (5+/-2%), while LCT (18+/-3%) and SL (20+/-1%) had no effect. N-formyl-methionyl-leucyl-phenylalanine- (fMLP, 10(-8)M) or zymosan-activated-serum-induced (ZAS, 10%) filter passage under lipid-free conditions amounted to 61+/-14% and 70+/-13%, respectively. These values decreased with LCT/MCT to 11+/-9% and 15+/-7%; with LCT/MCT-E to 18+/-10% and 28+/-12%; with SL to 39+/-18% and 57+/-14%, and with MCT to 5+/-2% and 10+/-6%, (all P<0.01), while LCT had no effect. Compared to LCT/MCT, the alpha -tocopherol-enriched formulation significantly increased ZAS- and fMLP-induced chemotaxis. fMLP-induced chemotaxis decreased in direct proportion to LCT/MCT triglyceride concentration. Conclusions: Human neutrophil migration is distinctively inhibited by structurally different lipid emulsions, depending on triglyceride chain-length and concentration as well as alpha -tocopherol content.     

不同磷脂／甘油三酯比的脂肪乳剂对大鼠血脂的影响

目的：观察不同磷脂／甘油三酯比的脂肪乳剂对血脂的影响。方法：雄性Wistar大鼠随机分成3组,分别经上腔静脉插管输入等热量的磷脂／甘油三酯比分别为0．06和0．12的脂肪乳剂或不做处理,连续应用24h。于实验后检测 油三酯,磷脂,胆固醇的变化。结果：应用脂肪乳剂后血甘油三酯两组均有提高,但各组间无明显差别。但与应用磷脂／甘油三酯比为0．06的脂3肪乳剂相比,输入磷脂／甘油三酯比为0．12的脂肪乳剂后,血磷脂,胆固醇显升高,结论：磷脂／甘油三酯比而非甘油三酯是引起血脂蓄积的原因,应用低磷脂／甘油三酯比的脂肪乳剂可减少血脂蓄积。     

Inhibition of lymphocyte proliferation in vitro by two lipid emulsions with different fatty acid compositions

The effects of two lipid emulsions upon the proliferation of rat and human lymphocytes in vitro were investigated. The emulsions used were Intralipid, a soya bean oilbased emulsion in widespread clinical use, and Omegavenous, a newly-developed emulsion in which n-3 polyunsaturated fatty acids comprise approximately 40% of the total fatty acids. Both emulsions inhibited lymphocyte proliferation in a concentration- and time-dependent manner. Omegavenous was a much more potent inhibitor than Intralipid.     

富含n-3多不饱和脂肪酸的肠外营养对脓毒症大鼠T淋巴细胞亚群和炎性因子的影响

目的:探讨富含n-3多不饱和脂肪酸(PUFA)的肠外营养(PN)对脓毒症大鼠外周血T淋巴细胞亚群和血清炎性因子的影响。方法:将36只大鼠随机分为四组,颈静脉置管术2 d后行盲肠结扎穿孔术或假手术,1对照组:给予自由饮食;2NS组:给予等渗盐水输注+自由饮食;3SO组:给予富含豆油的标准肠外营养(PN)液;4FO组:给予富含PUFA的PN液。脓毒症5 d后,检测IL-6、IL-10和T细胞亚群等。结果:脓毒症5 d后,FO组大鼠外周血CD3+、CD4+、CD4+/CD8+与NS组和SO组比有所升高,但较对照组大鼠下降;与NS组大鼠比,FO组血清IL-6、IL-10、外周血Tregs比例有所下降。结论:应用富含n-3 PUFA的PN可降低脓毒症大鼠血清炎性因子和调控外周血T淋巴细胞亚群。     

Effect of short-term dietary intake of bovine lactoferrin on intestinal lymphocyte apoptosis in healthy mice

OBJECTIVE: The objective of this study was to describe the effects of short-term dietary exposure of bovine lactoferrin (Lf) on intestinal lymphocyte apoptosis and expression of tumor necrosis factor-alpha (TNF-alpha) in healthy mice. METHODS: Female C57BL/6 mice were randomly assigned to three treatment groups: 0% Lf (n = 16), 0.2% Lf (n = 16), and 2.0% Lf (n = 15). Bovine Lf was administered orally, as part of the diet, for 4 consecutive days. Intestinal lymphocytes (ILs) were isolated and analyzed for percentages of CD4, CD8, apoptotic CD4, and apoptotic CD8 cells using flow cytometry. Pro- (caspase-3) and anti- (Bcl-2) apoptotic protein expressions and TNF-alpha expression in ILs were determined by Western blotting. RESULTS: There were significant increases in the percentages of CD4 (P = 0.02) and apoptotic CD4 (P = 0.02) ILs in bovine Lf-fed compared with control mice. Percentages of CD8 and apoptotic CD8 cells and expression of caspase-3 and Bcl-2 in ILs did not differ significantly by diet group. In contrast, the expression of TNF-alpha was significantly lower in Lf-fed versus control mice (P = 0.01). CONCLUSION: Short-term dietary Lf decreased TNF-alpha expression in ILs and increased apoptosis of CD4 ILs in healthy mice.     

亚麻籽油对TPN支持的腹腔感染大鼠血清细胞因子的影响

目的 :探讨亚麻籽油 (LO)对全肠外营养 (TPN)支持腹腔感染大鼠血清细胞因子的影响。　方法 :采用盲肠结扎加穿孔 (CLP)的腹腔感染模型。将大鼠随机分为三组 :A组 (假手术 )、B组 (NS加CLP加TPN)及C组 (LO加CLP加TPN) (每组n =12 )。术前分别灌喂等渗盐水或亚麻籽油 1ml,连续 2周 ,术后B、C组大鼠给予TPN支持。CLP后第 5天采集标本检测大鼠血清TNF、IL 6浓度。　结果 :B组和C组与A组比较 ,腹腔感染 5天后大鼠血清TNF、IL 6水平均明显增高 (P <0 .0 1) ;而C组大鼠血清TNF、IL 6水平又较B组下降 ,差异显著 (P <0 .0 5 )。　结论 :补充亚麻籽油可下调TPN支持的腹腔感染大鼠血清TNF、IL 6水平     

Effects of soy pinitol on the pro-inflammatory cytokines and scavenger receptors in oxidized low-density lipoprotein-treated THP-1 macrophages

Pinitol, a methylated form of D-chiro-inositol, acts as a insulin mediator. We investigated the effects of soy pinitol on the factors involved in foam cell formation using differentiated THP-1 macrophages. Pinitol slightly inhibited the lipid-laden foam cell formation by oxidized low-density lipoprotein (oxLDL) in a dose-dependent manner. Tumor necrosis factor-alpha and monocyte chemoattractant protein-1 releases were significantly reduced by pinitol treatment (0.05-0.5 mM), whereas interleukin-1beta and interleukin-8 secretions were significantly reduced in low-dose pinitol (0.05 or 0.1 mM) and 0.5 mM pinitol-treated cells, respectively, compared to no pinitol-treated cells. Gene expressions of CD36 and CD68 were significantly down-regulated by 0.05-0.5 mM pinitol compared to the oxLDL-treated control cells. Matrix metalloproteinase-9 gene expression was significantly decreased in 0.05-0.5 mM pinitol-treated cells compared to the no pinitol-treated macrophages. We conclude that pinitol has some inhibitory effects on foam cell formation by reducing lipid accumulation, secretion, and expression of some cytokines and macrophage scavenger receptor expression via its insulin-like action.     

大气污染物对大鼠肺炎性细胞因子影响

目的研究大气污染物对大鼠肺炎性细胞因子的影响，探讨大气污染对呼吸系统炎性损伤的机制。方法48只Wistar大鼠，体重200～240g，随机分为实验组（1d组、7d组和30d组）和对照组。实验组分别进行可吸入颗粒物（PM10）染尘，SO2、NO2和CO染毒。PM10染尘采用气管注入法，灌注1ml含15mgPM10生理盐水混悬液；染毒采用静态吸入SO2、NCh、CO空气混合气，浓度分别为15，12，400mg/m^3，每天吸入2h，分别吸入1，7及30d；对照组大鼠气管注入1ml生理盐水并吸入正常空气。分别于染毒后1．7，30d进行支气管肺泡灌洗。观察灌洗液中自细胞总数及其分类；采用ELISA法测定支气管肺泡灌洗液（BALF）中炎性细胞因子水平。结果实验组大鼠BALF中，白细胞总数、中性粒细胞百分比明显升高，与对照组比较差异有统计学意义（P〈0．05或P〈0．01）。1d组大鼠BALF中。肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、白细胞介素-8（IL-8）及白细胞介素-10（IL-10）水平均明显高于对照组（P〈0．05），各炎性细胞因子间有较好的相关性。结论大气污染物可引起大鼠肺促炎细胞因子与抗炎细胞因子表达失衡，造成肺组织的炎性损伤。