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。     

亚油酸对红细胞膜磷脂脂肪酸组成的作用

亚油酸（１８∶２ｎ６）是必需脂肪酸（ＥＦＡ）。肠外营养（ＰＮ）中应用中链／长链脂肪乳剂（ＭＣＴ／ＬＣＴ）,即中链脂肪乳剂和长链脂肪乳剂各一半物理混合形成的脂肪乳剂,含有ＥＦＡ,以１０％的ＬｉｐｏｆｕｎｄｉｎＭＣＴ／ＬＣＴ为例,１８∶２ｎ６占脂肪酸总量的２６％。为探明１８∶２ｎ６对维持红细胞（ＲＢＣ）膜磷脂脂肪酸组成平衡的意义,我们进行下列研究。　　　１　材　料　与　方　法１．１　动物及分组　　禁食２４ｈ后,体重１９２～２２８ｇ的２４只Ｗｉｓｔａｒ大鼠随机分为三组,每组８只。（１）对照组：右…     

糖尿病患者中链和长链甘油三酯乳剂的清除比较

比较胰岛素非依赖性糖尿病患者中/长链甘油三酯(MCT/LCT)混合乳剂和长链甘油三酯(LCT)乳剂的清除率。每组各6例,在4小时输入脂肪期间,MCT/LCT组血甘油三酯达稳定状态。动力学参数表明MCT/LCT乳剂有着明显较小的表观分布容积和较短的半衰期。两种乳剂对血糖浓度也有不同的影响。在葡萄糖和脂肪代谢紊乱时,如需行含脂肪的肠外营养,应优先选择MCT/LCT混合乳剂。     

围手术期中链和长链甘油三酯乳剂的清除动力学比较

本研究以１４例择期胆囊切除术病人为创伤模型，观察创伤前后机体应用中链甘油三酯／长链甘油三酯（ＭＣＴ／ＬＣＴ）和ＬＣＴ乳剂的清除动力学变化。结果表明，脂肪乳剂输入和清除期间无不良反应。术后两种乳剂的清除均加速。ＭＣＴ／ＬＣＴ乳剂输入后血胰岛素浓度明显升高。对血糖的影响可能与脂肪乳剂的代谢速度及胰岛素的影响有关。     

中链脂肪乳剂的临床应用

脂肪乳剂是肠外营养的重要组成部分，静脉输注脂肪乳剂除提供机体代谢所需的能量外，还为机体提供了生物膜和生物活性物质代谢所需的多不饱和脂肪酸，而且可以防止或纠正机体必需脂肪酸的缺乏。目前临床上常用的脂肪乳剂是富含长链甘油三酯的脂肪乳剂，其大剂量或长期使用被认为可影响机体网状内皮系统、肝脏等重要脏器的功能。含中链甘油三酯的脂肪乳剂，     

Intralipid与Lipofudin在重症胰腺炎病人中的应用

目的：研究两种碳链不同的脂肪乳剂对重症胰腺炎病人肠外营养支持效果，观察脂肪乳剂对胰腺炎病程、血浆游离脂肪酸的影响以及营养支持效果。 方法：将３０例重症胰腺炎病人随机分为Ｉｎｔｒａｌｉｐｉｄ（Ｌ组）、Ｌｉｐｏｆｕｄｉｎ（Ｍ组）、无脂肪乳剂驵（Ｃ组）予以肠外营养（ＴＰＮ）支持，并测定电解质、血糖、转铁蛋白、前白蛋白、甘油三酯、胆固醇、血清游离脂肪酸、磷脂酶Ａ２、弹性蛋白、肝功能、Ｔ细胞亚群等指标，进行     

脂肪乳剂对人肠道相关淋巴组织的影响

探讨脂肪乳剂对胃肠道肿瘤患者肠道相关淋巴组织的影响。方法：20例胃肠道癌症患者随机分为含脂组（n＝10）和无脂组（n＝10），分别接受全肠外营养（TPN）支持7天后，分离肠系膜淋巴结和肠粘膜固有层的淋巴细胞，调细胞浓度至1×109／L，以植物血凝素（PHA）诱导培养48小时，测其上清液中肿瘤坏死因子α（TNF－α）和可溶性白介素-2受体（sIL-2R）含量。结果：含脂组肠系膜淋巴结淋巴细胞中TNF－α显著降低（P＜0．05），而肠粘膜固有层淋巴细胞中sIL-2R显著增高（P＜0．05）。结论：脂肪乳剂对肠道相关淋巴组织的诱导部位和效应部位均有抑制作用。     

静脉输注长链或中长链脂肪酸脂肪乳剂对急性坏死性胰腺炎大鼠脂质介质的影响

目的：探讨静脉输注长链或中长链脂肪酸脂肪乳剂对急性坏死性胰腺炎（ANP）大鼠血浆脂质介质及胰腺病理改变的影响。方法：雄性SD大鼠43只随机入组，A－C为非胰腺炎组：A组为正常组；B组正常大鼠输注脂肪乳剂；C组为手术对照组，输注葡萄糖液。D－F为ANP模型组：分别为全糖组，Intralipid组和Lipofundin组。测定A组血淀粉酶、前列腺素类，胰腺行病理学检查。测定B－F组术后4、48及72h血淀粉酶、前列腺素类，胰腺病理学检查并评分。结果：正常大鼠输注Intralipid不引起血前列腺素的变化。在胰腺炎各组，脂肪乳剂可提高4h6－keto-PGF1α、PGE2血浆浓度；Lipofundin组胰腺组织的出血和脂肪坏死明显减少。结论：脂肪乳剂不加重ANP大鼠胰腺组织病理损害；LCT／MCT脂肪乳剂更适合应用于ANP。     

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。     

脂肪乳剂在重症肝病中的应用

本文介绍了脂肪乳剂的概况，新型脂肪乳剂研制及其在重症肝病应用研究中的进展。研究结果表明，新型脂肪乳剂更适用于重症肝病的全肠道外营养（ＴＰＮ）；脂肪乳剂在重症肝病患者ＴＰＮ中的应用是安全的，并已成为ＴＰＮ中重要的营养物质脂肪乳剂的应用剂量要控制在每日每公斤体重１ｇ以内，并以适应输送速度输入（血浆甘油三酯的升高〈３ｍｍｏｌ／Ｌ）。     

Effects of medium-chain triglyceride in parenteral nutrition on rats undergoing gastrectomy

This study was designed to investigate the effects of pre-infusion with total parenteral nutrition (TPN) using medium-chain triglyceride (MCT) versus long-chain triglyceride (LCT) emulsion as fat sources on hepatic lipids, inflammatory mediators and antioxidant capacity in rats undergoing gastrectomy. Rats with internal jugular catheter, were divided into two groups and received TPN. TPN supplied 300 kcal/kg/d with 39% of the energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was composed of MCT/LCT (1 : 1) or LCT. After receiving TPN for 5 days, the rats underwent partial gastrectomy and were sacrificed 24 h after surgery. The results of the study demonstrated that the MCL/LCT group had lower hepatic lipids than did the LCT group. No differences in interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha in peritoneal lavage fluid were observed between the two groups. Erythrocyte glutathione peroxidase activity was significantly higher in the LCT group than the MCT/LCT group, although erythrocyte superoxide dismutase activity did not differ significantly between the two groups. These results suggest that infusion with MCT/LCT before an abdominal operation did not have an effect on modulating the production of inflammatory mediators in the location of the injurious stimulus. However, pre-infusion with MCT/LCT have beneficial effect in improving liver lipid metabolism and reducing oxidative stress in rats with gastrectomy.     

MCT/LCT emulsion ameliorate liver fat deposition in insulin-treated diabetic rats receiving total parenteral nutrition

This study was designed to investigate the effects of high energy infusion and insulin treatment on plasma and liver lipids in diabetic rats receiving total parenteral nutrition (TPN). Diabetes was induced in rats by streptozotocin. The diabetic rats were assigned to two TPN groups to receive either long chain triglyceride (LCT) or medium chain triglyceride (MCT)/LCT (1:1) as a fat source. The TPN solutions were isonitrogenous, isocaloric and identical in nutrient composition except for the fat emulsion. All rats received the TPN solution at an energy level of 35|kcal/100|g of body weight. The LCT and MCT/LCT groups were further divided into two subgroups, depending on whether they were treated with insulin. The results demonstrated that, between the MCT/LCT and LCT groups, no differences were observed in body weight and nitrogen retention, as well as the concentrations of plasma glucose, nonesterified fatty acids, beta-hydroxybutyrate, and total cholesterol. Diabetic TPN rats without insulin treatment had weight loss and negative nitrogen balance during the experiment. Diabetic TPN rats treated with insulin, however, demonstrated less weight loss and positive nitrogen retention. Insulin treated groups had significantly higher liver fat content than did those without insulin treatment. Furthermore, liver fat content was significantly higher in the LCT group than in the MCT/LCT group among insulin treated TPN rats. These results suggest that compared with the LCT emulsion, infusion of the MCT/LCT emulsion ameliorated liver fat deposition in insulin-treated diabetic rats receiving TPN.     

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.     

Effect of structured lipids as energy substrate after hepatectomy in rats with streptozocin-induced diabetes.

The suitability of energy substrates for use by the remnant liver after 70% hepatectomy was studied in relation to the hepatic energy status in diabetic rats. Rats with streptozocin-induced diabetes underwent 70% hepatectomy and were divided into five groups receiving total parenteral nutrition (TPN) for 24 h. One group received standard TPN without fat, and four groups respectively received standard TPN with long-chain triglycerides (LCTs), medium-chain triglycerides (MCTs), mixed triglycerides (MIX), or structured lipids (SLs) as a 10% lipid emulsion. The latter groups received 60% of nonprotein calories per day with fat emulsion (LCT, MCT, MIX, or SL), and the remaining 40% with glucose. The group that received 100% of nonprotein calories per day with glucose was defined as the TPN group. All rats in the TPN group died from nonketotic hyperosmolarity within 24 h. The blood ketone body ratio (acetoacetate/beta-hydroxybutyrate), the energy charge level of the remnant liver, and the cumulative excretion of 14CO2 in expired breath during 6 h after [14C]glucose administration were all significantly higher in the SL group than in the other groups 24 h after hepatectomy. These findings suggest that SL may be a superior energy substrate to other triglyceride preparations during the immediate posthepatectomy phase in diabetic patients.     

Effects of parenteral structured lipid emulsion on modulating the inflammatory response in rats undergoing a total gastrectomy

OBJECTIVES: Structured lipid emulsion improves the nitrogen balance and is rapidly cleared from the blood of moderately catabolic patients. However, the effects of structured lipids on inflammatory reactions during major surgery are not clear. This study investigated the effect of a parenteral structured triacylglycerol emulsion on leukocyte adhesion molecule expression and inflammatory mediator production in rats undergoing a total gastrectomy. METHODS: Normal rats with internal jugular catheters were assigned to three experimental groups and received total parenteral nutrition. At the same time, a total gastrectomy was performed on the experimental groups. The total parenteral nutrition solutions were isonitrogenous and identical in nutrient compositions except for differences in the composition of the fat emulsion. Group 1 received a conventional fat emulsion with long-chain triacylglycerols (LCTs), group 2 received a physical mixture of medium-chain triacylglycerols (MCTs) and LCTs (MCT/LCT), and group 3 received structured lipids composed of MCTs and LCTs (STG). Half of the rats in each respective group were sacrificed 1 d and the other half 3 d after surgery to examine the analytical parameters. RESULTS: Plasma cholesterol and free fatty acid levels in the STG group were lower than those in the other groups after surgery. The STG group had lower leukocyte CD11a/CD18 expressions than the MCT/LCT group 3 d after surgery, and CD11b/CD18 expressions in the STG group were lower than those in the LCT group on postoperative days. The STG group had higher monocyte chemotactic protein-1 and macrophage inflammatory protein-2 levels in peritoneal lavage fluid than did the other two groups. CONCLUSION: These results suggest that, compared with the LCT and MCT/LCT groups, rats administered STG had lower plasma lipid concentrations and leukocyte integrin expressions. In addition, STG administration may cause increased recruiting of neutrophils and monocytes at the site of injury and enhance antipathogenicity in rats undergoing a total gastrectomy.     

脂肪乳剂对完全胃肠外营养大鼠血清游离脂肪酸谱的影响

为研究脂肪乳剂对机体脂肪代谢的影响，用气相色谱法观测了完全胃肠外营养（ＴＰＮ）大鼠血清游离脂肪酸（ＦＦＡ）谱的变化。将４０只雄性Ｗｉｓｔａｒ大鼠随机分成５组，每组８只：（１）ＳＨ（Ｓｈａｍｏｐｅｒａｔｉｏｎ）组，仅进行颈外静脉结扎，正常饲养；（２）ＮＳ（Ｎｏｔｍａｌｓａｌｉｎｅ）组：正常饲养，输入生理盐水；（３）ＧＳ（Ｇｌｕｃｏｓｅ）组：全部能量由葡萄糖提供，即不含脂肪乳剂ＴＰＮ组；（４）ＬＣＴ（Ｌｏｎｇｃｈａｉｎｔｒｉｇｌｙｃｅｒｉｄｅ）组：含１０％Ｉｎｔｒａｌｉｐｉｄ脂肪轧的ＴＰＮ组；（５）ＭＣＴ（Ｍｅｄｉｕｍｃｈａｉｎｔｒｉｇｌｙｃｅｒｉｄｅ）组：含１０％Ｌｉｐｏｆｕｎｄｉｎ脂肪乳ＴＰＮ组。ＴＰＮ各组大鼠等能量等氮量等液量匀速连续输入“生合一”营养液（即将所有营养物混合在一个溶器内）。于第７天取血标本进行血清ＦＦＡ测定。结果表明：不含脂肪乳的ＴＰＮ大鼠血清各种ＦＦＡ下降，并出现必需脂肪酸缺乏（ＥＦＡＤ）症状，如精神不振活动少，毛发无光泽、脱落等；脂肪乳剂的使用，使大鼠血清各种ＦＦＡ升高，对机体的代谢和功能有着不同的生理、药理作用。     

Effect of Medium-Chain Triglyceride Emulsion in Total Parenteral Nutrition on Experimental Hepatic Metastasis in the Rat

Background: This study evaluated the effect of total parenteral nutrition (TPN) regimens containing a medium-chain triglyceride (MCT) emulsion on tumor metastasis. Methods: Tumor metastasis development was assessed by the number of metastatic foci on the liver surface in rats inoculated with ACL-15 tumor cells via the portal vein. Rats received one of the following TPN regimens: TPN containing an MCT emulsion (group M), in which tricaprylin emulsion served as the MCT and comprised 50% of nonprotein calories (NPC); TPN containing a long-chain triglyceride (LCT) emulsion (group L), in which soybean oil served as the LCT and comprised 50% of NPC; and TPN without lipid emulsion (group G), in which dextrose comprised 100% of NPC. Results: The number of metastatic foci was greatest in rats receiving TPN containing the MCT emulsion on day 11 after tumor cell inoculation and either 11 days of TPN or 2 days of TPN followed by 9 days standard rat chow. Conclusions: TPN containing MCT emulsion increases liver metastasis early in its administration. (Journal of Parenteral and Enteral Nutrition 21:220–223, 1997)     

Comparison of effects of long-chain and medium-chain triglyceride emulsions during hepatic regeneration in rats.

We examined the effect of long-chain triglyceride (LCT) and medium-chain triglyceride (MCT) emulsions on hepatic regeneration. After approximately 70% hepatectomy, Sprague-Dawley rats were maintained for 96 hours on total parenteral nutrition (TPN) (250 kcal/kg per day; nonprotein calories-nitrogen 160:1) with LCT or MCT as 30% of nonprotein calories. There were no significant differences in the body weight, cumulative nitrogen balance, urinary 3-methylhistidine excretion, or changes in the energy stores between the two groups; but the fatty acid composition of the phospholipid fraction of the regenerating liver differed significantly between the LCT and the MCT groups. The extent of hepatic regeneration by weight was 88.7 +/- 10.5% in the MCT group and 99.1 +/- 10.6% in the LCT group by 96 hours after hepatectomy. Furthermore, the incorporation of 3H-orotic acid into DNA and RNA of regenerating liver cells in the LCT group was higher than in the MCT group 24 hours after hepatectomy. These observations indicate that essential fatty acids--components of the cell membrane and precursors as functional mediators--are very important to hepatic regeneration.     

Changes of hepatic morphology during parenteral nutrition with lipid emulsions containing LCT or MCT/LCT quantified by ultrasound.

Fatty infiltration of the liver with cholestasis is one of the complications of total parenteral nutrition (TPN). The cause has not yet been determined. It seems probable, however, that these alterations could be prevented when a mixture of medium- and long-chain triglycerides (MCT/LCT) is used as a fat component instead of the application of long-chain emulsions (LCT) alone. To determine whether this could also be demonstrated morphologically in man, 14 patients needing TPN (25 kcal/kg BW x day, carbohydrate 45%, fat 35%, protein 20%) were examined by ultrasound in order to compare liver size and gray-scale value before and after 7 days of TPN. Seven of the patients were randomly administered a MCT/LCT emulsion as their fat intake, the other seven were exclusively given LCT. There were no changes in liver size and gray-scale value in the MCT/LCT-group, whereas both parameters showed a significant rise in the patients with LCT (size: 10.4 +/- 1.4 to 11.5 +/- 1.4 cm; gray-scale value: 9.3 +/- 1.0 to 11.6 +/- 0.7). These data suggest that TPN, administered with a mixture of MCT/LCT emulsions as fat components, could reduce the risk of hepatic dysfunction such as cholestasis and fatty infiltration of the liver.     

Effects of medium-chain and long-chain triacylglycerols in pediatric surgical patients

Medium-chain triacylglycerols (MCTs) have been shown to provide better nutritional support than long-chain triacylglycerols (LCTs). This study compares the efficacy of MCT combined with LCT with LCT alone in pediatric patients with surgical stress. Two groups of patients (n = 19 in each) received equivalent amounts of glucose (12 g. kg. d) and amino acids (2 g. kg. d), but one group received 10% Lipofundin MCT/LCT and the other received 10% LCT (1.5 g. kg. d) in a randomized study. Total parenteral nutrition (TPN) was given for 14 d. Blood and urine samples were collected before and after TPN administration for determination of various biochemical parameters. Indirect calorimetry was also performed to determine respiratory quotients and fuel utilization. After 14 d of TPN in the MCT/LCT group, there was a significantly higher blood lymphocyte percentage, a decreasing tendency of serum asparate aminotransferase and of total and direct bilirubin (P < 0.05). These changes were not observed in the LCT group. A significantly better nitrogen balance and a higher ketogenesis from day 3 were observed in the MCT/LCT group. The MCT/LCT group showed a more marked increased utilization of fat than the LCT group, whereas carbohydrate oxidation was less in the MCT/LCT group than in the LCT group (P < 0.05). In children after surgery, MCT/LCT is more protein sparing and induces a better immune response when compared with LCT-containing lipid emulsion. A TPN regimen containing MCT/LCT is likely to result in rapid oxidation of fats for energy without compromising the respiratory system.