Administration Of Fat Emulsion Research Articles

Effect of fat emulsion administration on blood coagulation in terminal lung cancer patients.

Patients with cancer, especially those with lung cancer, are at high risk of developing thrombosis. Intralipos® infusion 20% is contraindicated for thrombosis, and there is no consensus on whether it can be safely used in cases of advanced cancer. We conducted a retrospective observational study to elucidate the impact of fat emulsion administration on blood coagulation in patients with terminal lung cancer. The subjects were patients with terminal lung cancer in the Department of Surgery and Palliative Medicine, Fujita Health University Nanakuri Memorial Hospital between January 2016 and December 2019. We compared changes in their blood coagulation profile before hospitalization and one month later. There were a total of 213 patients with lung cancer-139 who were administered fat emulsion and 74 who were not-with no significant differences in baseline characteristics. In the fat emulsion administration group (n=27), the prothrombin time-international normalized ratio (PT-INR) and activated partial thromboplastin time (APTT), respectively, were 1.17±0.26 (mean±standard deviation) and 30.5±5.0s at hospitalization and 1.16±0.12 and 31.2±4.2s one month later with no significant differences. In the non-administration group (n=6), the PT-INR and APTT, respectively, were 1.44±0.43 and 30.6±5.2s before hospitalization and 1.28±0.18 and 33.0±7.5s one month later with no significant differences. We did not identify any changes in PT-INR and APTT after fat emulsion administration in patients with terminal lung cancer. There were also no new cases of thrombosis, suggesting that fat emulsions were administered safely in patients with terminal lung cancer.

The lipid-lowering effects of fenugreek gum, hawthorn pectin, and burdock inulin.

The present study aimed to investigate the lipid-lowering effects and mechanisms of fenugreek gum (FG), hawthorn pectin (HP), and burdock inulin (BI) on high-fat diet (HFD)-induced hyperlipidemic rats. In this study, high-fat diet (HFD) together with fat emulsion administration were used to establish hyperlipidemia model. The biochemical indices were assayed after administration of FG, HP, and BI. Their effects were evaluated by factor analysis. Alterations of gut microbiota and short chain fatty acids (SCFAs) in the cecal were assessed to illustrate the mechanism of lipid lowering. The supplementation of FG, HP, and BI on HFD-fed rats decreased the levels of serum lipid and reduced the HFD-related liver and testicle damage. In the scatter plot of factor analysis, HP and BI were closer to normal fat diet (NFD) group in restoring the severity of hyperlipidemia, while FG and HP enhanced the excretion of cholesterol and bile acids (BAs). The levels of total SCFAs, especially butyric acid reduced by HFD were increased by HP. The ratio of Firmicutes to Bacteroidetes increased by HFD was reduced by HP and BI. FG, HP, and BI enriched intestinal probiotics, which were related to bile acid excretion or lipid-lowering. FG inhibited the absorption of cholesterol and enhanced the excretion of it, as well as increased the abundance of beneficial bacteria. While BI restored the imbalance of intestinal microbiota. HP enhanced the excretion of cholesterol and BAs, and restored the imbalance of intestinal microbiota. It was also utilized by intestinal microorganisms to yield SCFAs. This study suggested that FG, HP, and BI possessed the potential to be utilized as dietary supplements for obesity management.

Fatty Acid Supplementation Affects Skin Wound Healing in a Rat Model

Polyunsaturated fatty acids (PUFA) play an important role in reparative processes. The ratio of PUFAs n-3 to n-6 may affect wound healing. The study aimed to evaluate the effect of dietary supplementation with n-3 and n-6 PUFA in two proportions on skin wounds in laboratory rats. Adult male Wistar rats received 20% fat emulsion with a ratio of 1.4:1 (group A) or 4.3:1 (group B) for n-3:n-6 PUFAs at a daily dose of 1 mL/kg. The control group received water under the same conditions. The animals were supplemented a week before and a week after the skin excision performed on the back. The level of wound closure, various parameters of oxidative stress, and plasma fatty acids composition were evaluated. Wound tissue samples were examined by electron microscopy. The administration of fat emulsions led to significant changes in plasma polyunsaturated fatty acid composition. The increased production of reactive nitrogen species, as well as more numerous newly formed blood vessels and a greater amount of highly organized collagen fibrils in both groups A and B may indicate more intensive healing of the skin wound in rats supplemented with polyunsaturated fatty acids in high n-3:n-6 ratio.

Establishment of blood lipids variation-based experimental hyperlipidemia animal model: a review

Nowaday, the prevalence of dyslipidemia has developed into a global public health problem. The screening of lipid-lowering active substances and the study of their mechanism have received extensive attention, and the establishment of hyperlipidemia model is the premise of relative studies. In the study, hyperlipidemic animal models established with different factors such as dietary composition, food/environmental pollution factors and drug stimulation are summarized and analyzed from the aspects of blood lipid changes, inducer ratio/dose, modeling mechanism and modeling cycle. It is shown that 4 – 8 weeks free feeding of high-fat diet and 4 – 6 weeks intragastric administration of fat emulsion can cause lipid accumulation in experimental animals; egg yolk or fat emulsion injection can cause a significant increase in plasma triglycide in animals within 2 hours – 2 days. The high-fat/high-glucose-induced C. elegans or zebrafish high-fat model can be used as a rapid screening model for lipid-lowering actives. Both food contaminant 1, 3-dichloro-2-propanol and environmental pollutant heavy metal lead can induce stable mixed hyperlipidemia; detergents Triton and poloxamer can induce an acute model with clear mechanism; and hormone can induce kidney deficiency type hyperlipidemia. Congenital dyslipidemia and gene knockout models are often applied to in-depth mechanistic studies. The establishment method of hyperlipidemia model has various advantages and disadvantages. It is necessary to establish a suitable/efficient high-fat model according to studies on the development of natural lipid-lowering active substances.

Novel “Matrix-Corrected Calibration” study for the detection of polyunsaturated fatty acids (PUFAs) in plasma and erythrocytes by means of a gas chromatography-mass spectrometry approach optimized to follow up long-term parental patients

An accurate and specific gas chromatography-mass spectrometry (GC-MS) method was optimized to quantify specific polyunsaturated fatty acids (PUFAs) in plasma and in erythrocyte membranes for clinical purposes. The developed and fully-validated method showed optimal linearity in addition to adequate results in terms of accuracy, intra-day and inter-day precision. By adopting the Matrix-Corrected Calibration approach on all the biological matrices tested, both the constant and the proportional errors of the developed analytical methodology were considered to assure that the method was not affected by matrix bias. Moreover, a pilot study involving patients in parental nutrition with two different compositions of the administered fat emulsion was performed. The comparison of results obtained in these patients with a group of healthy subjects (i.e. control population) showed significant differences in the collected values of PUFAs in both plasma and erythrocyte membranes, thus providing evidence that the described GC-MS method could be employed as a simple tool for fast and accurate PUFAs analysis aimed at optimizing parenteral nutrition protocols.

Protective effect and mechanism of Qiwei Tiexie capsule on 3T3-L1 adipocytes cells and rats with nonalcoholic fatty liver disease by regulating LXRα, PPARγ, and NF-κB-iNOS-NO signaling pathways

Ethnopharmacological relevanceQiwei Tiexie capsule (QWTX) is a representative prescription of Tibetan medicine, which is widely used for long-term treatment of chronic liver disease and nonalcoholic fatty liver disease (NAFLD). Aim of the studyThis study explored the effects and mechanism of QWTX on 3T3-L1 adipocytes and NAFLD. Materials and methodsThe 3T3-L1 preadipocytes and NAFLD rat model were used in the study. In 3T3-L1 cells, the cytotoxicity of QWTX was tested by CKK-8, and glucose uptake and fat acid oxidation were assessed by 2-deoxy-D-[3H] glucose and [1–14C] palmitic acid, respectively. The expression levels of carnitine palmitoyltransferase-1 (CPT-1), liver X receptor α (LXRα), peroxisome proliferator-activated receptor (PPAR) γ, inducible nitric oxide synthase (iNOS), ikappa B α (IκBα), and AKT were determined by PCR and western blot. NAFLD was established by the administration of fat emulsion and sucrose for 9 weeks. The effects of QWTX on lipid metabolism, liver function, and hepatic morphology were observed in NAFLD rats by HE and transmission electron microscope. Serum level of nitric oxide (NO) and fee fatty acid (FFA), superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the liver, as well as the expression levels of Cytochrome P450 2E1 (CYP2E1), NF-κB, monocyte chemoattractant protein 1 (MCP-1), CPT-1, LXRα, PPARα, PPARβ/δ, PPARγ, and iNOS were all detected. ResultsQWTX showed no cell cytotoxicity in 3T3-L1 preadipocyte cells, and increased the 14CO2 production rate to 4.15, which indicated the reducing the fatty accumulation. In NAFLD, QWTX attenuated liver steatosis, fat vacuoles and inflammation from the HE staining and electron micrograph tests. For the oxidative stress biomarkers, serum FFA level was reduced and serum NO level was enhanced after QWTX treatment. In liver tissue, SOD was decreased and MDA was significantly increased in NAFLD, and both of them were restored by QWTX. NF-κB and CYP2E1 were also upregulated in NAFLD, while downregulated by QWTX. Downregulation of LXRα, PPARγ and iNOS by QWTX were both observed in the 3T3-L1 adipocytes and NAFLD model. ConclusionsQWTX protected the liver injury in differentiated 3T3-L1 adipocytes and NAFLD by regulating the LXRα, PPARγ, and NF-κB-iNOS-NO signal pathways.

Vitamin K1 distribution following intravenous vitamin K1-fat emulsion administration in rats.

This study investigated vitamin K1 (VK1 ) distribution following intravenous vitamin K1-fat emulsion (VK1 -FE) administration and compared it with that after VK1 injection. Rats were intravenously injected with VK1-FE or VK1 . The organ and tissue VK1 concentrations were determined using high-performance liquid chromatography method at 0.5, 2 and 4 h to determine distribution, equilibrium and elimination phases, respectively. In the VK1-FE group, the plasma, heart and spleen VK1 concentrations decreased over time. However, other organs like liver, lung, kidney, muscle and testis, reached peak VK1 concentrations at 2 h. In the VK1 injection group, the liver VK1 concentrations were significantly higher than those in other organs at the three time points. However, VK1 concentrations in the other organs peaked at 2 h. In addition, in VK1-FE group, the heart, spleen and lung VK1 concentrations were significantly higher than those in the VK1 injection group at the three time points, and the liver VK1 concentration was significantly higher than that in the VK1 injection group at 4 h. The VK1 amount was greatest in the liver compared with the other organs. Thus, the liver is the primary organ for VK1 distribution. The distribution of VK1 is more rapid when injected as VK1-FE than as VK1 .

Verapamil reverses cardiac iron overload in streptozocin-induced diabetic rats

Accumulating evidence shows that iron overload is a new risk factor for diabetes mellitus. L-type Ca(2+) channel (LTCC) has been identified as an important mediator for ferrous iron uptake into cardiomyocytes. In this study, we aimed to examine the effects of verapamil, the LTCC blocker, on myocardial iron metabolism in diabetic rats. Diabetes was induced by intraperitoneal injection of streptozocin after intragastric administration of fat emulsion, and then treated by verapamil (5 mg · kg(-1) · day(-1)) for 1 week. The results showed that verapamil did not alter the blood glucose level of diabetic rats. However, elevated levels of superoxide dismutase, malonaldehyde, and serum ferritin in diabetic rats were decreased significantly by verapamil treatment. Moreover, serum, myocardial, and urine iron were elevated remarkably along with a decrease of hepatic iron in diabetic rats. After verapamil administration, serum and myocardial iron in diabetic rats were reduced significantly but urine and hepatic iron were increased. Furthermore, confocal microscopy demonstrated that intracellular-free iron concentration was elevated dramatically in cardiomyocytes of diabetic rats, which was markedly attenuated after verapamil treatment. In summary, our data demonstrated that verapamil prevented myocardial iron overload by inhibiting intracellular iron accumulation in diabetic cardiomyocytes.

Agglutination of Intravenously Administered Phosphatidylcholine‐Containing Lipid Emulsions With Serum C‐reactive Protein

C-reactive protein (CRP) is able to bind phospholipids in the presence of calcium. We wanted to investigate the reaction of CRP with various commercial fat emulsions and to explore the impact of CRP agglutination on serum CRP levels. Serum specimens were mixed with Intralipid 20% (soybean oil-based fat emulsion), Structolipid (structured oil-based fat emulsion), Omegaven (fish oil-based fat emulsion), or SMOFlipid (mixed soybean oil-, olive oil-, and fish oil-based emulsion) in Tris-calcium buffer (pH 7.5). After 30 minutes of incubation at 37°C, CRP-phospholipid complexes were turbidimetrically quantified and flow cytometric analysis was performed. Similarly, CRP complexes were monitored in vivo, following administration of fat emulsion. CRP was able to agglutinate phospholipid-containing lipid droplets present in the soybean oil-based fat emulsion and the structured oil-based fat emulsion. To a lesser extent, agglutination was observed for fish oil-containing fat emulsions, whereas no agglutination was noticed for the mixed soybean oil-, olive oil-, and fish oil-based emulsion. Results for propofol-containing emulsions were comparable. Agglutination correlated with phospholipid content of the emulsions. When in vivo agglutination occurred, plasma CRP values dropped due to consumption of CRP by phospholipid-induced agglutination. In this in vitro experiment, we demonstrated agglutination of CRP with phospholipids in various fat emulsions. Research studies are required in patients to determine which effects occur with various intravenous fat emulsions.

Postprandial lipemia and insulinemia in obese females with cholelithiasis

The authors studied the pattern of fatty tissue distribution in the body and revealed changes In the baseline and postprandial levels of serum lipids and insulin In females with cholelithiasis (CL) obese. Ninety-five females were examined. These included 41 patients with CL and obesity, 20 patients with the normal body mass index and CL, and 34 obese females without CL. The pattern of abdominal adipose tissue distribution was determined by computed tomography. The serum levels of major lipids and immunoreactive insulin (IRI) were measured at the baseline and 3 and 9 hours after administration of fat emulsion (130 g of fat per 2 m2 of body surface). There was a significant predominance of the area of visceral adipose tissue (VFT) at the level of the gallbladder. In the groups of CL patients, the percent of VFT of the total abdominal adipose tissue was higher than that in obese patients without CL. During a dietary fat load test, a persistent postprandial hypertriglyceridemia and no increases in the levels of high-density lipoprotein cholesterol were observed in CL female patients irrespective of whether systemic obesity was present or absent. In the group of CL patients without signs of obesity, there were high baseline concentrations of IRI and no significant increase in IRI levels in response to the administration of fat emulsion.

Metabolic effects of intravenous LCT or MCT/LCT lipid emulsions in preterm infants

Most lipid emulsions for parenteral feeding of premature infants are based on long-chain triacylglycerols (LCTs), but inclusion of medium-chain triacylglycerols (MCTs) might provide a more readily oxidizable energy source. The influence of these emulsions on fatty acid composition and metabolism was studied in 12 premature neonates, who were randomly assigned to an LCT emulsion (control) or an emulsion with a mixture of MCT and LCT (1:1). On study day 7, all infants received [13C]linoleic (LA) and [13C]alpha-linolenic acid (ALA) tracers orally. Plasma phospholipid (PL) and triacylglycerol (TG) fatty acid composition and 13C enrichments of plasma PL fatty acids were determined on day 8. After 8 days of lipid infusion, plasma TGs in the MCT/LCT group had higher contents of C8:0 (0.50 +/- 0.60% vs. 0.10 +/- 0.12%; means +/- SD) and C10:0 (0.66 +/- 0.51% vs. 0.15 +/- 0.17%) than controls. LA content of plasma PLs was slightly lower in the MCT/LCT group (16.47 +/- 1.16% vs. 18.57 +/- 2.09%), whereas long-chain polyunsaturated derivatives (LC-PUFAs) of LA and ALA tended to be higher. The tracer distributions between precursors and products (LC-PUFAs) were not significantly different between groups. Both lipid emulsions achieve similar plasma essential fatty acid (EFA) contents and similar proportional conversion of EFAs to LC-PUFAs. The MCT/LCT emulsion seems to protect EFAs and LC-PUFAs from beta-oxidation.

Efficacy of Medium-chain Triglycerides Compared with Long-chain Triglycerides in Total Parenteral Nutrition in Patients with Digestive Tract Cancer Undergoing Surgery

The objectives of this prospective, randomized study were to evaluate the efficacy and tolerability of the short-term use of medium-chain triglyceride/long-chain triglyceride (MCT/LCT) fat emulsions, and to compare the hematologic and biochemical effects of MCT/LCT fat emulsions with LCT fat emulsions in gastrointestinal (GI) tract cancer patients following surgery. Thirty patients with GI tract cancer requiring total parenteral nutrition (TPN) were equally randomized to receive MCT/LCT or LCT emulsions for 7 days. After 7 days, no sign of complications directly related to administration of fat emulsions was observed and there were no marked differences in anthropometry, length of hospital stay, and surgical complication rates between the two groups. However, MCT/LCT significantly improved plasma prealbumin concentration (p = 0.005). Changes in complements C3 and C4, total lymphocyte count, and immunoglobulins after TPN were not significantly different between the groups. Serum triglyceride and cholesterol levels remained constant. The serum insulin level in the MCT/LCT group was higher than in the LCT group (p = 0.048). Our data revealed that MCT/LCT fat emulsions significantly enhanced nutritional status in patients with GI tract cancer, indicated by higher prealbumin levels, which might be partially due to the higher circulating insulin levels in the MCT/LCT group.

Effects of Oral Fat Load on Insulin Output and Glucose Tolerance in Healthy Control Subjects and Obese Patients Without Diabetes

Elevated plasma nonesterified fatty acid (NEFA) concentrations cause peripheral and hepatic insulin resistance and may play an important role in regulating glucose-induced insulin secretion. The aim of our study was to investigate the influence of physiologically elevated NEFA levels on glucose-stimulated insulin secretion in order to find evidence that NEFAs are a potential factor predisposing for type 2 diabetes and related metabolic disorders, which are known risk factors for cardiovascular disease. We combined an orally administered fat emulsion with an intravenous glucose tolerance test and measured the time course of NEFA, insulin, and glucose. In order to find pathological conditions we applied the experiment to healthy and obese subjects. The main findings are a significant increase in glucose-stimulated insulin secretion after oral fat load in both groups compared with the condition without preceding fat ingestion and a prolonged insulin secretion after fat load in obese patients compared with control subjects. The results provide evidence that fat ingestion modulates beta-cell function and that NEFA is a plausible mediator that acts as a link between fat and glucose metabolism by modulating glucose-stimulated insulin secretion. Under the condition of elevated plasma levels of NEFA, this mechanism may be responsible for hyperinsulinemia in obese patients and a potential target of type 2 diabetes prevention strategies.

The Impact of IV Fat Emulsion Administration in Acute Lung Injury

The aim of this study was to evaluate the effect of parenteral nutrition containing medium‐ and long‐chain triglycerides on the function of the respiratory system and to investigate mechanisms involved in this process. We studied 13 patients with acute respiratory distress syndrome (ARDS), 8 receiving lipid and 5 placebo, and 6 without ARDS, receiving lipid. Bronchoalveolar lavage (BAL) was performed before and 1 hour after administration of lipid or placebo. In patients with ARDS, lipid administration resulted in deterioration of oxygenation (PaO2/FIO2: from 129 ± 37 to 95 ± 42), compliance of respiratory system (from 39.2 ± 12 to 33.1 ± 9.2 mL/cm H2O), and pulmonary vascular resistance (from 258 ± 47 to 321 ± 58 dyne·s·cm–5). In the BAL fluid of the same group, an increase in total protein and phospholipid concentrations, phospholipase activities, platelet‐activating factor and neutrophils, and alterations in BAL lipid profile were observed. No significant changes were observed in the control or in the ARDS‐Placebo groups. In conclusion, this study indicates that administration of medium‐ and long‐chain triglycerides in patients with ARDS causes alterations in lung function and hemodynamics. Inflammatory cells, possibly activated by lipids, release phospholipase A2 and platelet‐activating factor, enhancing edema formation, inflammation, and surfactant alterations.

Significance of administration of fat emulsion: hepatic changes in infant rats receiving total parenteral nutrition with and without fat

Total parenteral nutrition (TPN) is associated with cholestasis and hepatic steatosis, which can be lethal in infants who cannot be fed orally. The present animal study focused on the metabolic complications in the liver that may occur due to the excessive administration of fat-free TPN. Thirty infant (3-week-old) male SD rats weighing 60−70 g were randomly allocated to five groups ( n=6): the OD group received an oral diet, the FT group received an oral diet and was fasted overnight on the last day of experiment before sacrifice, the 0% fat group received TPN without fat, the 20% fat group received TPN with 20% of calories from fat emulsion, and the 40% fat group received TPN with 40% of calories from fat emulsion. All TPN regimens were isocaloric, isonitrogenic, and administered for 4 days. In the 0% fat group, plasma levels of liver enzymes were significantly higher than in the other groups. Pathological examination showed hepatomegaly and severe fatty changes without cholestasis in the 0% fat group. The results of this study in infant rats indicate the importance of including fat in the TPN regimen in order to prevent the abnormal hepatic changes associated with the excessive administration of fat-free TPN.

Significance of administration of fat emulsion: Hepatic changes in infant rats receiving total parenteral nutrition with and without fat

Significance of administration of fat emulsion: Hepatic changes in infant rats receiving total parenteral nutrition with and without fat

ε-Polylysine Inhibits Pancreatic Lipase Activity and Suppresses Postprandial Hypertriacylglyceridemia in Rats

Epsilon-polylysine (epsilon-PL) has been used as a food additive in Japan for many years. In this study, it inhibited human and porcine pancreatic lipase activity in substrate emulsions containing bile salts and phosphatidylcholine, in the concentration range of 10-1000 mg/L. At the same concentrations, it also destroyed the emulsifying activity, suggesting that lipase inhibitory activity and emulsion breakdown activity were associated. Epsilon-PL inhibited porcine pancreatic lipase activity and destroyed emulsion breakdown activity at 1000 mg/L in the substrate containing bile salts and phosphatidylcholine alone. Epsilon-PL did not inhibit lipase activity or affect emulsifying activity at 1000 mg/L in the substrates containing arabic gum and polyvinyl alcohol. A comparison of lipase inhibitory activity between epsilon-PL and three types of alpha-PL with differing polymerization rates was performed. The lipase inhibitory activity of epsilon-PL was not different from that of alpha-PL (44 lysine residues). Epsilon-PL maintained its inhibitory activity after incubation with trypsin, alpha-chymotrypsin and pepsin, whereas alpha-PL did not. The effect of epsilon-PL on postprandial hypertriacylglyceridemia was investigated in rats. The plasma triacylglycerol concentration in rats intragastrically administered > or =15 mg/kg of both fat emulsion and epsilon-PL was significantly lower at 2 and 3 h after administration than that in rats administered fat emulsion alone (P < 0.05). These results strongly suggest that epsilon-PL is able to suppress dietary fat absorption from the small intestine by inhibiting pancreatic lipase activity.

COMPARISON OF THE FAT ELIMINATION BETWEEN LONG-CHAIN TRIGLYCERIDES AND MEDIUM-CHAIN TRIGLYCERIDES IN RATS WITH ISCHEMIC ACUTE RENAL FAILURE

To guide the administration of fat emulsion in the nutritional support of acute renal failure (ARF), pharmacokinetic analysis with an one-compartment open model after bolus intravenous injection was performed to compare the elimination kinetics of long-chain triglycerides (LCT) and medium-chain triglycerides (MCT) in ischemic acute renal failure rats. Sprague-Dawley rats were randomized into four groups, namely LCT normal group, LCT ARF group, MCT normal group and MCT ARF group. The model of ischemic acute renal failure was induced by clamping the left renal artery for 60 min and contralateral nephrectomy. All the rats were fasted with water ad libitum for 10 h before 0.3 g/kg body weight of 10% Intralipid (LCT) or 10% Lipofundin (MCT:LCT = 50:50) was injected as a bolus to them via the tail vein. The serum triglyceride concentration was determined at 2, 10, 40, 70, 100, 130 and 160 min after intravenous injection for kinetic analysis. The results showed that the elimination rate constant (ke) of LCT ARF group was significantly decreased, while the half life period (t1/2) of it was significantly longer than those of LCT normal group. The ke and t1/2 of MCT showed no statistical difference between normal and ARF groups. In the normal group the ke of LCT was significantly decreased compared with MCT whereas the t1/2 was significantly prolonged. In the ARF group the ke of LCT was much less than that of MCT while the t1/2 was much longer. The serum insulin levels of both MCT groups were significantly higher than those of LCT groups. These results indicate that MCT will be eliminated more rapidly than LCT in ARF rats. MCT may also increase the secretion of insulin. In conclusion, MCT may be more favorable than LCT in the nutritional management of ARF.

Acute psychological stress reduces plasma triglyceride clearance

Acute stress elevates blood lipids, with the largest increases among men and postmenopausal women. The mechanisms for the effect are unknown, but may be due to altered lipid metabolism. This study investigated if acute stress induces transient reductions in triglyceride clearance in middle‐aged men and women, and determined if gender and menopause affect triglyceride metabolism. Of the 35 women, half were premenopausal, and half were naturally postmenopausal; men (n= 35) were age matched. Clearance of an intravenously administered fat emulsion was assessed twice: once during a nonstress session, and again during a stress‐testing session. During the stress session, a battery of behavioral stressors (serial subtraction, speech, mirror tracing, and Stroop) were performed for 40 min. The clearance rate of exogenous fat was significantly diminished during the stress, relative to the nonstress session. Women had more efficient clearance, relative to men, but there were no effects of menopausal status. The diminished ability to clear an intravenous fat emulsion during stress suggests one mechanism for stress‐induced elevations in lipids.

Metabolism of parenterally administered fat emulsions in the rat: studies of fatty acid oxidation with 1-13C- and 8-13C-labelled triolein.

To reassess the hypothesis that fatty acid catabolism occurs to completion via beta-oxidation, male Sprague-Dawley rats receiving continuous total parenteral nutrition (TPN) including 43% energy as fat were infused with [1-(13)C]- or [8-(13)C]triolein. Expired CO2 was collected continuously for 4 h and its 13C:12C ratio determined by isotope-ratio mass spectrometry. Bicarbonate retention was also assessed over 4 h by infusion of NaH14CO3 and measurement of the expired 14CO2. A possible loss of label from [8-(13)C]oleic acid from the citric acid cycle via labelled acetyl-CoA without oxidation to CO2 was assessed by infusing further animals with acetate labelled with 14C either at C atoms 1 or 2 and determination of its conversion to expired 14CO2. At isotopic steady state, 63.2 (SE 1.6)% (n 8) of the infused [1-(14)C]acetate and 46.0 (SE 1.2)% (n 8) of [2-(14)C]acetate was recovered as expired 14CO2. After correction for bicarbonate retention and non-oxidative isotope loss, 37.3 (SE 1.2)% (n 20) of the [1-(13)C]triolein was found to have been oxidized, whereas 32.6 (SE 1.0)% (n 20) of the [8-(13)C]triolein was oxidized (P < or = 0.01). The lower oxidation of the C atom at position 8 of oleic acid than that at position 1 indicates incomplete oxidative breakdown of the fatty acid after entering beta-oxidation.