RESUMO
In the present study, we investigated the effect of long-acyl chain SFA, namely palmitic acid (16:0) and stearic acid (18:0), at sn-1, 3 positions of TAG on obesity. Throughout the 15 weeks of the experimental period, C57BL/6 mice were fed diets fortified with cocoa butter, sal stearin (SAL), palm mid fraction (PMF) and high-oleic sunflower oil (HOS). The sn-1, 3 positions were varied by 16:0, 18:0 and 18:1, whilst the sn-2 position was preserved with 18:1. The HOS-enriched diet was found to lead to the highest fat deposition. This was in accordance with our previous postulation. Upon normalisation of total fat deposited with food intake to obtain the fat:feed ratio, interestingly, mice fed the SAL-enriched diet exhibited significantly lower visceral fat/feed and total fat/feed compared with those fed the PMF-enriched diet, despite their similarity in SFA-unsaturated fatty acid-SFA profile. That long-chain SFA at sn-1, 3 positions concomitantly with an unsaturated FA at the sn-2 position exert an obesity-reducing effect was further validated. The present study is the first of its kind to demonstrate that SFA of different chain lengths at sn-1, 3 positions exert profound effects on fat accretion.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Gordura Intra-Abdominal/metabolismo , Ácido Oleico/efeitos adversos , Ácido Palmítico/efeitos adversos , Ácidos Esteáricos/efeitos adversos , Gordura Subcutânea/metabolismo , Triglicerídeos/efeitos adversos , Adiposidade , Animais , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/metabolismo , Fezes/química , Absorção Intestinal , Gordura Intra-Abdominal/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Obesidade/prevenção & controle , Ácido Oleico/análise , Ácido Oleico/metabolismo , Óleo de Palmeira , Ácido Palmítico/análise , Ácido Palmítico/metabolismo , Óleos de Plantas/efeitos adversos , Óleos de Plantas/metabolismo , Distribuição Aleatória , Ácidos Esteáricos/análise , Ácidos Esteáricos/metabolismo , Gordura Subcutânea/patologia , Óleo de Girassol , Triglicerídeos/análise , Triglicerídeos/metabolismo , Trioleína/efeitos adversos , Trioleína/análise , Trioleína/metabolismo , Aumento de PesoRESUMO
BACKGROUND AND AIMS: Vegan diet excludes all foodstuffs of animal origin and leads to cholesterol lowering and possibly reduction of cardiovascular disease risk. The aim was to investigate whether vegan diet improves the metabolic pathway of triglyceride-rich lipoproteins, consisting in lipoprotein lipolysis and removal from circulation of the resulting remnants and to verify whether the diet alters HDL metabolism by changing lipid transfers to this lipoprotein. METHODS AND RESULTS: 21 vegan and 29 omnivores eutrophic and normolipidemic subjects were intravenously injected triglyceride-rich emulsions labeled with (14)C-cholesterol oleate and (3)H-triolein: fractional clearance rates (FCR, in min(-1)) were calculated from samples collected during 60 min for radioactive counting. Lipid transfer to HDL was assayed by incubating plasma samples with a donor nanoemulsion labeled with radioactive lipids; % lipids transferred to HDL were quantified in supernatant after chemical precipitation of non-HDL fractions and nanoemulsion. Serum LDL cholesterol was lower in vegans than in omnivores (2.1 ± 0.8, 2.7 ± 0.7 mmol/L, respectively, p < 0,05), but HDL cholesterol and triglycerides were equal. Cholesteryl ester FCR was greater in vegans than in omnivores (0.016 ± 0.012, 0.003 ± 0.003, p < 0.01), whereas triglyceride FCR was equal (0.024 ± 0.014, 0.030 ± 0.016, N.S.). Cholesteryl ester transfer to HDL was lower in vegans than in omnivores (2.7 ± 0.6, 3.5 ± 1.5%, p < 0,05). Free-cholesterol, triglyceride and phospholipid transfer were equal, as well as HDL size. CONCLUSION: Remnant removal from circulation, estimated by cholesteryl oleate FCR was faster in vegans, but the lipolysis process, estimated by triglyceride FCR was equal. Increased removal of atherogenic remnants and diminution of cholesteryl ester transfer may favor atherosclerosis prevention by vegan diet.
Assuntos
Dieta Vegetariana , Lipoproteínas HDL/metabolismo , Lipoproteínas/farmacocinética , Triglicerídeos/farmacocinética , Adulto , Radioisótopos de Carbono , Ésteres do Colesterol/sangue , LDL-Colesterol/sangue , Emulsões/administração & dosagem , Emulsões/farmacocinética , Feminino , Humanos , Lipólise , Lipoproteínas/administração & dosagem , Lipoproteínas HDL/química , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Tamanho da Partícula , Triglicerídeos/administração & dosagem , Trioleína/análise , TrítioRESUMO
The proton-decoupled natural abundance carbon-13 nuclear magnetic resonance spectrum of the canine sciatic nerve is virtually identical to that of canine adipose tissue and markedly similar to that of liquid triolein. No resonances assignable to cholesterol, glycolipids, or sphingolipids are detectable in the sciatic nerve spectrum despite their abundance in the myelin sheath of this nerve. However, many such resonances are observed in lipid extracts of the nerve. Chronmatographic analysis of specimens of canine and rabbit sciatic nerve has revealed that these contain sufficient triglyceride to account quantitatively for the observed spectrum. Proton nuclear magnetic resonance and spin-labeling results for preparations containing myelin, especially those derived from the peripheral nerve, should be critically examined for experimental artifacts reflecting the triglyceride content.
Assuntos
Lipídeos/análise , Espectroscopia de Ressonância Magnética , Nervo Isquiático/análise , Tecido Adiposo/análise , Animais , Isótopos de Carbono , Cães , Feminino , Bainha de Mielina/análise , Fosfolipídeos/análise , Coelhos , Esfingolipídeos/análise , Triglicerídeos/análise , Trioleína/análiseRESUMO
Camellia oleifera, C. japonica and C. sinensis are three representative crops of the genus Camellia. In this work, we systematically investigated the lipid characteristics of these seed oils collected from different regions. The results indicated significant differences in acid value (AV), peroxide value (PV), iodine value (IV), saponification value (SV) and relative density of the above-mentioned camellia seed oils (p < 0.05). The C. japonica seed oils showed the highest AV (1.7 mg/g), and the C. sinensis seed oils showed the highest PV (17.4 meq/kg). The C. japonica seed oils showed the lowest IV (79.9 g/100 g), SV (192.7 mg/g) and refractive index (1.4633) of all the oils, while the C. sinensis seed oils showed the lowest relative density (0.911 g/cm3). The major fatty acids in the camellia seed oils were palmitic acid (16:0), oleic acid (18:1) and linoleic acid (18:2); the oleic acid in C. oleifera and C. japonica seed oils accounted for more than 80% of the total fatty acids. The oleic acid levels in the C. oleifera and C. japonica oils were higher than those in the C. sinensis seed oils, while the linoleic acid levels in the former were lower than those in the latter one. Differences also exist in the triacylglycerol (TAG) composition, although the most abundant TAG molecular species in the camellia seed oils was trioleoylglycerol (OOO). Seven sterol species, squalene and α-tocopherol were detected in the camellia seed oils, however, the contents of tocopherol and unsaponifiable molecules in the C. oleifera and C. japonica seed oils were significantly lower than those in the C. sinensis seed oil. These results demonstrated that the varieties of Camellia affected the seed oil lipid characteristics.
Assuntos
Camellia/química , Ácido Linoleico/análise , Ácido Oleico/análise , Ácido Palmítico/análise , Óleos de Plantas/química , Sementes/química , Camellia/classificação , Fenômenos Químicos , Ácido Linoleico/isolamento & purificação , Ácido Oleico/isolamento & purificação , Ácido Palmítico/isolamento & purificação , Fitosteróis/análise , Fitosteróis/isolamento & purificação , Esqualeno/análise , Esqualeno/isolamento & purificação , Triglicerídeos/análise , Triglicerídeos/isolamento & purificação , Trioleína/análise , Trioleína/isolamento & purificação , alfa-Tocoferol/análise , alfa-Tocoferol/isolamento & purificaçãoRESUMO
Animal studies indicate that oversupply of fatty acids derived from the action of cardiac lipoprotein lipase (LPL) on plasma lipoproteins may contribute to myocardial dysfunction. However, the contribution of circulating triglycerides to myocardial fatty acid supply in humans is not known. Six postabsorptive nondiabetic subjects who were scheduled for diagnostic coronary angiography were studied. (14)C oleate and a lipid emulsion labeled with (3)H triolein were infused to assess myocardial uptake of free fatty acids (FFAs) and triglycerides, as well as myocardial spillover of LPL-generated fatty acids. Six paired blood samples were taken from the femoral artery and the coronary sinus. Coronary sinus concentrations of unlabeled triglycerides were slightly, but not significantly, lower than arterial (P = 0.12), whereas labeled triglyceride concentrations were significantly lower in the coronary sinus than in the artery (P < 0.05; extraction fraction congruent with 11%). Triglycerides and FFAs accounted for approximately 17% and approximately 83%, respectively, of myocardial fatty acid uptake. Systemic and myocardial fractional spillover of LPL-generated fatty acids was 49.0 +/- 7% and 34.7 +/- 13%, respectively. The myocardium was a minor contributor to systemic triglyceride uptake ( approximately 3%) and a trivial contributor to systemic FFA production ( approximately 0.5%). These results indicate that circulating triglycerides may be a significant source of fatty acids for myocardial respiration.
Assuntos
Vasos Coronários/metabolismo , Miocárdio/metabolismo , Ácido Oleico/farmacocinética , Trioleína/farmacocinética , Idoso , Radioisótopos de Carbono/farmacocinética , Respiração Celular/fisiologia , Ácidos Graxos/metabolismo , Feminino , Humanos , Masculino , Ácido Oleico/sangue , Triglicerídeos/metabolismo , Trioleína/análise , Trítio/farmacocinéticaRESUMO
BACKGROUND: Brucea javanica oil (BJO), a traditional Chinese herbal medicine, has a variety of pharmacological activities and several BJO-related patent drugs have been widely used in China. PURPOSE: The objective of this study was to evaluate the gastric therapeutic effects of self-made BJO and its pharmaceutical potential to formulate novel BJO gastroretentive floating bead by comparing with commercial products. METHODS: BJO was extracted from the seeds of B. javanica, and its therapeutic effects were evaluated by comparing with commercial products in the treatment of human gastric cancer and gastric ulcer. Furthermore, the developed gastroretentive drug delivery system was evaluated by in vivo tests. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for detecting the concentration of glycerol trioleate in the pharma-cokinetic study was applied. RESULTS: The antitumor activity of BJO was stronger than that of the marketed preparation; the 50% inhibitory concentration (IC50) values of BJO extracts on HGC27, SGC7901 and BGC823 gastric carcinoma were 0.3091, 1.736 and 2.743 µg/mL, respectively, whereas the values of marked BJO preparation were 15.26, 32.60 and 7.456 µg/mL, respectively. Histopathological studies demonstrated the ability of BJO to locally prevent and treat absolute ethanol-induced gastric ulcer. Developed BJO gastroretentive floating bead showed a satisfactory in vivo study. The highest glycerol trioleate concentration in the stomach after taking BJO gastroretentive floating bead was nearly two times higher when compared to the marketed BJO soft capsule. CONCLUSION: Self-made BJO has a strong therapeutic effect on the stomach, and gastroretentive drug delivery system can be a promising approach to prolong and enhance its therapy ability when treating gastric diseases.
Assuntos
Brucea/química , Sistemas de Liberação de Medicamentos , Medicamentos de Ervas Chinesas/farmacologia , Óleos de Plantas/farmacologia , Úlcera Gástrica/tratamento farmacológico , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Humanos , Medicina Tradicional Chinesa , Estrutura Molecular , Óleos de Plantas/química , Óleos de Plantas/isolamento & purificação , Sementes/química , Úlcera Gástrica/patologia , Relação Estrutura-Atividade , Espectrometria de Massas em Tandem , Trioleína/análise , Células Tumorais CultivadasRESUMO
A rapid method, with minimal sample preparation and no chromatography, was developed for analyzing food samples such as olive oil and pomegranate juice to measure adulteration with cheaper ingredients using the novel Direct Sample Analysis™ (DSA) ion source in conjunction with a time-of-flight (TOF)-MS. In less than 30 s, with minimal sample preparation and method development, adulteration of olive oil and pomegranate juice with cheaper seed oils and fruit juices, respectively, was measured with DSA/TOF-MS.
Assuntos
Contaminação de Alimentos/análise , Sucos de Frutas e Vegetais/análise , Azeite de Oliva/análise , Lythraceae , Malatos/análise , Espectrometria de Massas , Olea , Óleo de Soja/análise , Tartaratos/análise , Triglicerídeos/análise , Trioleína/análiseRESUMO
In this work, we optimize parameters and conditions for analysis of fatty acid ester and acylglycerol lipids by atmospheric pressure photoionization-mass spectrometry (APPI-MS). The investigated parameters include atmospheric pressure chemical ionization (APCI) nebulizer/vaporizer physical orientation and APPI lamp face position, solvent selections, mobile phase compositions and flow rates, cone voltages and probe temperatures. APPI sensitivity is found to be highly dependent on mobile phase compositions. Normal phase solvents offer much higher sensitivity and better peak shape than reversed phase for nonpolar lipids. Hexane and isooctane are found to be two solvents generating highest S/N for eicosapentaenoic acid (EPA) methyl ester. The effects of mobile phase flow rates on sensitivity are found to be target analytes and target ions specific. However, the flow rate changes do not significantly affect the sensitivity of three out of four tested analytes under normal phase conditions over tested flow rates of 50-500muL/min. Cone voltage is found to be one of key parameters affecting sensitivity. Optimum probe temperature is found to be more dependent on mobile phase compositions than on the specific target analytes. Aqueous reversed-phase mobile phase requires higher probe temperature than normal phase for better sensitivity. More volatile mobile phase solvents require lower probe temperature for analyte desolvation. APPI offers four to five decades of linear ranges under normal phase condition. Full scan mass spectra of individual lipid standards, custom lipid mixtures and natural fish oil show that APPI spectra are clean and very easy to interpret. APPI also gives stable, reproducible peak responses with good peak shape. Limits of detection (LODs) by FIA (S/N=3) are estimated to be 12pg for EPA methyl ester and monoarachidin, 19pg for diarachidin and 7pg for trielaidin. LODs on-column are estimated to be 94pg for EPA methyl ester, 90pg for monoarachidin and diarachidin and 24pg for trielaidin.
Assuntos
Ácidos Graxos/análise , Glicerídeos/análise , Espectrometria de Massas/métodos , Pressão Atmosférica , Ácido Eicosapentaenoico/análise , Ésteres/análise , Óleos de Peixe/análise , Óleos de Peixe/química , Fotoquímica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solventes/química , Temperatura , Trioleína/análise , VolatilizaçãoRESUMO
Despite the considerable number of in vivo and in vitro studies on the digestive fate of lipophilic nutrients, micronutrients, and bioactives, the effects of the structure and composition of foods on the physicochemical mechanisms of luminal digestion are still poorly understood. Studying them is indeed complex because the number of parameters is high and many of them are interdependent. To solve this problem, an in silico simulation based on a multi-agent system was recently proposed to study the intestinal bioaccessibility of lipophilic nutrients and micronutrients from a single oil droplet. The roles of lipolysis and solubilization in bile salt were included. The effects of several food and digestion parameters were in line with those reported in the experimental literature. The goal of the research reported in this new article was to include more digestion parameters in the simulation in order to make it more realistic against complex cases. This was done in one specific digestion condition reflecting in vitro experiments, using droplets of tricaprylin or triolein containing vitamin A. The structure and principles of the original model were kept, with independent local modifications in order to study each factor separately. First, a gastric step was added where lipolysis took place, and only a marginal effect on the following intestinal step was found. Then, the chemical form of vitamin A, either non-hydrolyzed retinyl ester or retinyl ester instantly hydrolyzed into retinol, was investigated by considering different localizations in the droplet, resulting in a higher bioaccessibility for the retinol. The case of a mixture of tricaprylin and triolein indicated an influence of the oil phase viscosity. The consideration of mixed micelles compared to simple bile salt micelles was also investigated, and resulted in a higher vitamin A bioaccessibility, especially with triolein. Finally, a full model including the most influential parameters was tested to simulate the digestion of triglyceride-limonene mixtures, giving bioaccessibility trends in very good agreement with the literature.
Assuntos
Biologia Computacional/métodos , Gorduras na Dieta/metabolismo , Digestão , Sistemas Inteligentes , Absorção Intestinal , Modelos Biológicos , Vitamina A/metabolismo , Animais , Ácidos e Sais Biliares/química , Caprilatos/análise , Caprilatos/química , Caprilatos/metabolismo , Fenômenos Químicos , Simulação por Computador , Gorduras na Dieta/análise , Análise de Alimentos , Suco Gástrico/química , Suco Gástrico/enzimologia , Suco Gástrico/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lipólise , Solubilidade , Triglicerídeos/análise , Triglicerídeos/química , Triglicerídeos/metabolismo , Trioleína/análise , Trioleína/química , Trioleína/metabolismo , Viscosidade , Vitamina A/análise , Vitamina A/químicaRESUMO
Patients with exocrine pancreatic insufficiency have steatorrhoea as well as vitamin B12 malassimilation. To investigate whether this is caused by the pancreatic insufficiency per se or whether intestinal bacterial overgrowth contributes to the condition, 10 patients with pancreatic steatorrhoea were studied. Intestinal culture was done. Lipid and vitamin B12 assimilation was estimated from faecal spot tests, using 14C-triolein and 58Co-vitamin B12 as tracers and 51CrCl3 as marker. Out of the 10 patients, 9 had either vitamin B12 malassimilation (n = 8), and/or bacterial overgrowth (n = 5). These 9 patients were retested with pancreatic enzyme therapy, with and without addition of the antibiotics metronidazole and cefalexin. The lipid assimilation was significantly increased by enzyme therapy but did not improve further on additional antibiotic treatment. The vitamin B12 assimilation did not improve significantly on enzyme therapy nor with additional antibiotic treatment.
Assuntos
Gorduras na Dieta/metabolismo , Insuficiência Pancreática Exócrina/metabolismo , Vitamina B 12/metabolismo , Cefalexina/uso terapêutico , Radioisótopos de Cobalto , Terapia Enzimática , Fezes/química , Fezes/microbiologia , Humanos , Intestinos/microbiologia , Metronidazol/uso terapêutico , Pâncreas/enzimologia , Trioleína/análiseRESUMO
The radioactive triolein test has been compared with two chemical methods for the assessment of fat absorption in a group of inpatients from general medical wards. The special feature of the investigation is the use of a radioactive faecal marker to measure the completeness of faecal collections during the investigation period. Estimations of unabsorbed (131)I triolein and faecal fat measured by the chemical methods were made on the same specimens. The results showed that only 48% of the patients provided a complete collection of faeces (defined as a recovery of more than 90% of the faecal marker). From these patients good correlations were found between the triolein absorption test and the two chemical methods.It is suggested that previous criticism of the radioactive triolein test may have been due to incomplete faecal collections causing false results.
Assuntos
Gorduras/metabolismo , Absorção Intestinal , Radioisótopos do Iodo , Trioleína/metabolismo , Técnicas de Química Analítica , Isótopos do Cromo , Gorduras/análise , Fezes/análise , Humanos , Radioisótopos , Escândio , Trioleína/análiseRESUMO
The processes of chylomicron lipolysis and removal from plasma were investigated by the intra-arterial infusion of doubly labeled artificial chylomicrons in rats. The rate of lipolysis was measured as a delipidation index (DI), which is the glyceryl-tri-9,10(N)-3H oleate (3H-TO) fraction removed from the particle as fatty acids, whereas the cholesteryl(1-14C) oleate (14C-CO) plasma disappearance rate measures the splanchnic organ particle uptake. In the alloxan-diabetic rats, despite a normal DI, the 14C-CO plasma residence time (RT) was longer than in control animals and remained longer after stimulation of the lipoprotein lipase by heparin. DI and 14C-CO removal rate were not significantly altered by insulin administration to glucose-supplemented control rats. Lipolysis was remarkable in propylthiouracil (PTU)-induced hypothyroidism, and yet the 14C-CO removal rate was retarded. In hypothyroidism, heparin enhanced the 14C-CO removal more than in the control group; however, after heparin, the 14C-CO RT still remained higher in the hypothyroid animals as compared with the control group. Hyperthyroidism lowered the DI; nevertheless, the 14C-CO disappearance rate was faster than in controls. In summary, lack or excess of thyroid hormone influences both the chylomicron lipolysis and removal systems, whereas lack of insulin impairs mostly the particle removal from plasma, and excess of insulin has no effect on the chylomicron metabolism.
Assuntos
Quilomícrons/sangue , Insulina/farmacologia , Hormônios Tireóideos/farmacologia , Animais , Ésteres do Colesterol/sangue , Quilomícrons/síntese química , Diabetes Mellitus Experimental/sangue , Heparina/farmacologia , Hipertireoidismo/sangue , Hipotireoidismo/sangue , Lipólise , Masculino , Ratos , Ratos Endogâmicos , Trioleína/análiseRESUMO
Sorption of ethanol and water into stratum corneum, delipidized stratum corneum, and triolein as a simple model lipid was investigated. Optima in ethanol sorption and flux are related to dehydration of keratins. There was no optimum for solubility in triolein; a linear cosolvency is observed with ethanol:triolein mixtures. A model is proposed which qualitatively predicts the key features of ethanol-enhanced skin permeation on the basis of these solubility phenomena and a constant diffusion coefficient.
Assuntos
Etanol/farmacocinética , Absorção Cutânea , Água , Humanos , Técnicas In Vitro , Lipídeos/fisiologia , Masculino , Modelos Biológicos , Solubilidade , Trioleína/análise , ViscosidadeRESUMO
The 14C-triolein breath test, a recognised index of fat absorption, and the p-aminobenzoic acid (PABA) test, a 'tubeless' test of exocrine pancreatic function, have both been widely used in the diagnosis of malabsorption and exocrine pancreatic insufficiency. This study evaluates the potential of a combination of both tests in the investigation of fat absorption and exocrine pancreatic function. Combination of the tests has become technically feasible because of the introduction of high pressure liquid chromatography as the preferred method of analysis for PABA, and use of p-aminosalicylic acid (PAS) as the marker for PABA absorption and metabolism. We studied 25 healthy subjects, 11 patients with exocrine pancreatic disease and 12 patients with gastrointestinal disease. The combined test identified subjects with reduced fat absorption and distinguished subjects with exocrine pancreatic insufficiency from those with an intestinal cause of fat malabsorption. The test could be completed in 7 h and had high patient acceptability. These findings suggest that the combined 14C-triolein breath test and PABA test can be used as a non-invasive, 1-day investigation of fat absorption and exocrine pancreatic function.
Assuntos
Ácido 4-Aminobenzoico , Gorduras na Dieta/metabolismo , Síndromes de Malabsorção/diagnóstico , Trioleína/análise , Adulto , Idoso , Ácido Aminossalicílico , Testes Respiratórios , Dióxido de Carbono/análise , Diarreia/metabolismo , Feminino , Gastroenteropatias/metabolismo , Humanos , Absorção Intestinal , Masculino , Pessoa de Meia-Idade , Pancreatopatias/metabolismoRESUMO
The fatty acid composition of Sapindus mukorossi seed oil was determined by spectrophotometry, urea complexation, and gas liquid chromatography (GLC). The percentages of individual acids were found to be: palmitic, 4.0; stearic, 0.2; arachidic, 4.4; oleic 62.8; linoleic, 4.6; linolenic, 1.6; and eicosenoic, 22.4. Triglyceride composition was calculated from the fatty acid compositions of the native oil and of the monoglycerides produced from it by pancreatic lipase hydrolysis. The oil is composed of 0.1, 2.1, 22.0, and 75.8% trisaturated, monounsaturated disaturatd, diunsaturated monosaturated, and triunsaturated glycerides, respectively. The special characteristic of the Sapindus mukorossi seed oil is its content of 26.3 and 26.7% triolein and eicoseno-di-oleins, respectively.
Assuntos
Óleos/análise , Sementes/análise , Triglicerídeos/análise , Cromatografia Gasosa , Cromatografia em Camada Fina , Ácidos Graxos/análise , Ácidos Graxos Insaturados/análise , Lipase , Pâncreas/enzimologia , Trioleína/análiseRESUMO
Several recent studies have demonstrated that dietary DAG oil rich in 1,3-species suppresses the postprandial increase of serum TAG level and decreases body fat accumulation, compared with TAG oil. To clarify the mechanisms underlying the beneficial effects of DAG, we investigated the metabolic features of DAG in the small intestine with regard to the digestion pathway in the lumen and the TAG-synthesis pathway in the mucosa. When intraduodenally infused as an emulsion, TAG was digested to 1,2-DAG, 2-MAG, and FFA, whereas 1,3-DAG was digested to 1(3)-MAG and FFA. When assessed by the incorporation of [1-14C]linoleic acid in lipids, the mucosal TAG-synthesis was significantly reduced by DAG infusion compared with TAG infusion. However, the mucosal 1,3-DAG synthesis was remarkably increased in the DAG-infused rats. The total amount of mucosal 1,3-DAG was also increased (4.5-fold) after DAG infusion compared with that after TAG infusion. Next, we examined the synthesis pathway of 1,3-DAG. In cultures of the everted intestinal sacs, 1,3-DAG production required the presence of 1-MAG, suggesting that the 1,3-DAG synthesis was due to acylation of 1(3)-MAG in the DAG-infused rats. Furthermore, measurements of DAG acyltransferase activity indicated that 1,3-DAG was little utilized in TAG synthesis. These findings suggest that features of 1,3-DAG digestion and assimilation in the intestine may be responsible for the reduction of the postprandial serum TAG level by dietary DAG.
Assuntos
Diglicerídeos/metabolismo , Absorção Intestinal , Intestino Delgado/metabolismo , Aciltransferases/metabolismo , Animais , Diacilglicerol O-Aciltransferase , Digestão , Diglicerídeos/administração & dosagem , Diglicerídeos/química , Duodeno , Ácidos Graxos/metabolismo , Infusões Parenterais , Mucosa Intestinal/metabolismo , Ácido Linoleico/análise , Lipídeos/análise , Masculino , Micelas , Ratos , Ratos Wistar , Triglicerídeos/biossíntese , Trioleína/análiseRESUMO
Metabolism of carbohydrate and fat was examined in the hatching chick by introduction of 14C labeled oleic acid, triolein, or glucose to the gastrointestinal tract or to the yolk sac. Label in plasma and exhaled air samples were determined over a 12-h period. The activity-time curves could be fitted to double exponential equations, and rate constants for appearance and disappearance of label were calculated. Following injection to the yolk, oleic acid and triolein label showed rapid appearance in the circulation and rapid utilization. The rate of appearance of oleic acid and triolein in the circulation from the gastrointestinal tract was high at hatch and did not change with age. However, the rate constant for disappearance from the plasma increased with age and after 6 d posthatch disappearance curves fluctuated with little decline over 12 h. Following the introduction of labeled lipids more label was found in acylglycerides with time after injection but age had no effect. Lipids introduced via the yolk sac were present in higher proportions in fractions corresponding to low-density lipoprotein (LDL) than lipids introduced via the gastrointestinal tract. Glucose appearance in the circulation from the gastrointestinal tract was low at hatch and increased more than two-fold by 3 d posthatch. The rate constant for disappearance of glucose from the circulation did not change with age. It appears that lipoproteins synthesized maternally or in yolk transport lipids at hatch, but their concentration decreases posthatch, and this could reduce utilization of circulating lipids. Uptake of glucose increases after hatch, thus, allowing glucose to become a major source of energy as the yolk lipids are depleted.
Assuntos
Galinhas/crescimento & desenvolvimento , Galinhas/metabolismo , Glucose/metabolismo , Ácido Oleico/metabolismo , Trioleína/metabolismo , Animais , Glicemia/metabolismo , Dióxido de Carbono/análise , Radioisótopos de Carbono/análise , Digestão , Sistema Digestório/metabolismo , Glucose/administração & dosagem , Cinética , Lipoproteínas/sangue , Masculino , Ácido Oleico/administração & dosagem , Ácido Oleico/sangue , Fatores de Tempo , Trioleína/administração & dosagem , Trioleína/análise , Saco Vitelino/metabolismoRESUMO
A Fourier-transform infrared (FT-IR) spectroscopic method has been developed for assaying the bile salt-stimulated human milk lipase (BSSL, EC3.1) catalyzed hydrolysis of triolein in AOT reversed micelles in iso-octane. At 37 degrees C in 50 mmol dm-3 AOT the molar absorbtivities for the carbonyl stretching frequencies for triolein (at 1751 cm-1) and oleic acid (at 1714 cm-1) were 1646 dm3 mol-1 cm-1 and 743 dm3 mol-1 cm-1, respectively. The rate was linearly dependent upon the concentration of enzyme in the water pool up to 10 mg cm-3 and maximum activity was observed at a ratio (w0) of [H2O]:[AOT] = 16.7. Using these conditions, and in the presence of 10 mmol dm-3 sodium taurocholate (TC), the derived Michaelis-Menten parameters Vmax and Km were 57.5 mumol min-1 mg-1 and 5.53 mmol dm-3, respectively. These results are compared with those obtained in an oil-in-water microemulsion system and are discussed in terms of the relative partitioning of the enzyme and the substrate in the aqueous and oil phases and the interfacial concentration of the substrate in the two systems.
Assuntos
Ácidos e Sais Biliares/farmacologia , Lipase/análise , Micelas , Ácido Dioctil Sulfossuccínico , Emulsões , Feminino , Humanos , Cinética , Leite Humano/enzimologia , Ácidos Oleicos/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos , Trioleína/análise , Água/análiseRESUMO
A novel approach for the determination of pancreatic lipase (EC 3.1.1.3) activity by a spectrophotometric method is described. Enzyme activity is measured in the presence of 1 mmol/l triolein, a concentration much higher than usually employed in turbidimetry. The primary reaction medium is optimized as regards bile salt and colipase concentrations. The released fatty acids are enzymatically determined via a secondary reaction scheme using the constituents of a commercially available kit. The proposed method is easy to perform and may prove useful in determining lipase activity of standard lipase preparations, which is required for indirect assays. In addition to satisfactory precision and linearity as well as close correlation with other lipase assays, the procedure described in the present paper by-passes a number of short-comings (eg uncontrolled increase in absorbance) inherent to the turbidimetric methods.
Assuntos
Lipase/metabolismo , Pâncreas/enzimologia , Espectrofotometria/métodos , Trioleína/análise , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A method is described for construction of a novel amperometric triglyceride (TG) biosensor based on covalent co-immobilization of lipase, glycerol kinase (GK) and glycerol-3-phosphate oxidase (GPO) onto chitosan (CHIT) and zinc oxide nanoparticles (ZnONPs) composite film deposited on the surface of Pt electrode. The enzymes-ZnONPs-CHIT composite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The sensor showed optimum response within 6s at pH 7.5 and temperature of 35°C. The sensor measures current due to electrons generated at 0.4V against Ag/AgCl from H(2)O(2), which is produced from triolein by co-immobilized enzymes. A linear relationship was obtained between a wide triolein concentration range (50-650 mg/dl) and current (mA) under optimum conditions. The biosensor showed high sensitivity, low detection limit (20 mg/dl) and good storage stability (half-life of 7 months at 4°C). The biosensor was unaffected modified by a number of serum substances at their physiological concentrations. The biosensor was evaluated and employed for determination of TG in sera in apparently healthy subjects and persons suffering from hypertriglyceridemia.