RESUMO
This study determined the specific uptake rate of glucose and corn oil substrates used as carbon sources in batch cultures of Gibberella fujikuroi. We tested three biological models of growth rate: Monod, logistic and lag-exponential. With respect to the substrate consumption rate, we tested two models: constant cell yield (CCY) and law of mass action (LMA). The experimental data obtained from the culture with glucose as substrate correlated satisfactorily with the logistic/LMA model, indicating that the cell yield was variable. In the case of corn oil as carbon source, considering total residual lipids as substrate in the culture broth, the model with the best correlation was the lag-exp/CCY model. The quantification by GC of the three main fatty acids (linoleic, oleic and palmitic) in the culture medium showed a cumulative behavior, with a maximum concentration of each acid at 36 h. We established a more explicit mechanism of the consumption of corn oil, consisting of two stages: generation of fatty acids by hydrolysis and consumption by cellular uptake. The kinetic of hydrolysable lipids was of first order. We found that the hydrolysis rate of corn oil is not a limiting factor for the uptake of fatty acids by the microorganism. We also established, based on the analysis of the identical mathematical structure of consumption kinetics, that the uptake of fatty acids is faster than the uptake of glucose.
Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Óleo de Milho/metabolismo , Gibberella/crescimento & desenvolvimento , Glucose/metabolismo , Biomassa , Carbono/metabolismo , Meios de Cultura , Cinética , Lipídeos/química , Modelos LogísticosRESUMO
The aim of this study was to investigate the effects of trans-fatty acids (TFA) on liver and serum TAG regulation in mice fed diets containing different proportions of n-3, n-6 and n-9 unsaturated fatty acids (UFA) from olive (O), maize (C) or rapeseed (R) oils partially substituted or not with TFA (Ot, Ct and Rt, respectively). Male CF1 mice were fed (30 d) one of these diets. The effects of the partial substitution (1 %, w/w) of different UFA with TFA on the activity and expression of hepatic enzymes involved in lipogenesis and fatty acids oxidation were evaluated, as well as their transcription factor expressions. Some of the mechanisms involved in the serum TAG regulation, hepatic VLDL rich in TAG (VLDL-TAG) secretion rate and lipoprotein lipase (LPL) activity were assessed. In liver, TFA induced an increase in TAG content in the Ot and Rt groups, and this effect was associated with an imbalance between lipogenesis and ß-oxidation. In the Ot group, exacerbated lipogenesis may be one of the mechanisms responsible for the liver steatosis induced by TFA, whereas in Rt it has been related to a decreased ß-oxidation, compared with their respective controls. The enhanced hepatic VLDL-TAG secretion in the Ot and Rt groups was compensated with a differential removal of TAG by LPL enzyme in extrahepatic tissues, leading to unchanged serum TAG levels. In brief, the effects of low levels of TFA on liver and serum TAG regulation in mice depend on the dietary proportions of n-3, n-6 and n-9 UFA.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Gorduras Insaturadas na Dieta/metabolismo , Óleos de Plantas/metabolismo , Ácidos Graxos trans/farmacologia , Triglicerídeos/metabolismo , Animais , Óleo de Milho/química , Óleo de Milho/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-6/administração & dosagem , Ácidos Graxos Ômega-6/metabolismo , Fígado Gorduroso/metabolismo , Leucotrienos/metabolismo , Lipogênese , Lipase Lipoproteica/metabolismo , Lipoproteínas VLDL/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Azeite de Oliva/química , Azeite de Oliva/metabolismo , Oxirredução , Óleos de Plantas/química , Óleo de Brassica napus , Triglicerídeos/biossínteseRESUMO
It has been hypothesized that oils containing high levels of omega-3 polyunsaturated fatty acids, such as canola and fish oil, could counteract some of the adverse effects induced by phthalates. In the present study, the influence of different oily vehicles on di-butyl phthalate (DBP)-induced testicular toxicity and lipid profile was investigated. Pregnant Wistar rats were treated by oral gavage from gestation days 13 to 20 with DBP (500 mg/kg/day) diluted in three different vehicles: corn, canola or fish oil. Male fetuses were analyzed on gestation day 20. DBP exposure lowered intratesticular testosterone levels and anogenital distance, regardless of the vehicle used. The percentage of seminiferous cords containing multinucleated gonocytes and cord diameter was increased in DBP-exposed groups, compared with vehicle controls, with no difference between the three DBP-exposed groups. Clustering of Leydig cells was seen in all DBP groups. Lipid profile indicated that administration of canola and fish oil can increase the content of omega-3 fatty acids in rat testis. However, content of omega-3 was diminished in DBP-treated groups. Overall, our results indicate that different oily vehicles did not alter fetal rat testicular toxicity induced by a high DBP dose.
Assuntos
Dibutilftalato/toxicidade , Disruptores Endócrinos/toxicidade , Ácidos Graxos Ômega-3/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Exposição Materna/efeitos adversos , Veículos Farmacêuticos/metabolismo , Testículo/efeitos dos fármacos , Animais , Óleo de Milho/química , Óleo de Milho/metabolismo , Dibutilftalato/administração & dosagem , Disruptores Endócrinos/administração & dosagem , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/toxicidade , Ácidos Graxos Monoinsaturados/química , Ácidos Graxos Monoinsaturados/metabolismo , Ácidos Graxos Ômega-3/química , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Óleos de Peixe/química , Óleos de Peixe/metabolismo , Masculino , Veículos Farmacêuticos/química , Plastificantes/administração & dosagem , Plastificantes/toxicidade , Gravidez , Óleo de Brassica napus , Ratos , Processos de Determinação Sexual/efeitos dos fármacos , Testículo/embriologia , Testículo/metabolismo , Testosterona/metabolismoRESUMO
AIM: Our aim was to investigate the effects of trans-fatty acids (TFA) on liver lipid metabolism in mice fed on experimental diets rich in either oleic or linoleic acid. METHODS: Twenty-two male CF1 mice (22.0 ± 0.1 g) were fed with diets rich in corn oil or olive oil, supplemented or not with TFA (0.75 g TFA/100 g diet), for 4 weeks. Changes in triacylglycerol content, the activity and expression of enzymes involved in lipogenesis and fatty acid oxidation were measured. RESULTS: Supplementation of an olive oil-rich diet with TFA increased liver triacylglycerols, the activity and expression of lipogenic enzymes and sterol regulatory element-binding protein SREBP-1a expression. By contrast, when TFA were added to a corn oil-rich diet, they did not modify these parameters. No significant differences were observed among the experimental groups in the activity and expression of carnitine palmitoyltransferase-Ia, body and liver weights or serum triacylglycerol concentrations. CONCLUSIONS: The effect of TFA on liver fat accumulation depends on the dietary fatty acid composition. Steatosis induced by TFA when included in an olive oil diet (but not in a corn oil diet) was associated with an increased lipogenesis but not with a decreased fatty acid oxidation in animals fed on the olive oil diet. This metabolic change is mediated by SREBP-1a but not by SREBP-1c, and seems to be independent of insulin.
Assuntos
Gorduras na Dieta/metabolismo , Fígado Gorduroso/etiologia , Regulação da Expressão Gênica , Metabolismo dos Lipídeos , Fígado/metabolismo , Ácidos Graxos trans/efeitos adversos , Animais , Óleo de Milho/efeitos adversos , Óleo de Milho/metabolismo , Gorduras na Dieta/efeitos adversos , Fígado Gorduroso/enzimologia , Fígado Gorduroso/metabolismo , Hidrogenação , Ácido Linoleico/efeitos adversos , Ácido Linoleico/metabolismo , Lipogênese , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos , Ácido Oleico/efeitos adversos , Ácido Oleico/metabolismo , Azeite de Oliva , Oxirredução , Óleos de Plantas/efeitos adversos , Óleos de Plantas/metabolismo , Distribuição Aleatória , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/efeitos adversos , Triglicerídeos/metabolismoRESUMO
BACKGROUND: High-fat diets are usually associated with greater weight (W) gain and body fat (BF). However, it is still unclear whether the type and amount of fat consumed influence BF. Additionally, dietary fat intake may also have consequences on skeletal health. OBJECTIVE: To evaluate in healthy growing rats the effects of high-fat diets and type of dietary fat intake (saturated or vegetable oils) on energy and bone metabolism. METHODS: At weaning, male Wistar rats (n = 50) were fed either a control diet (C; fat = 7% w/w) or a high-fat diet (20% w/w) containing either: soybean oil, corn oil (CO), linseed oil (LO), or beef tallow (BT) for 8 weeks. Zoometric parameters, BF, food intake and digestibility, and total and bone alkaline phosphatase (b-AP) were assessed. Total skeleton bone mineral density (BMD) and content (BMC), BMC/W, spine BMD, and bone volume (static-histomorphometry) were measured. RESULTS: Animals fed BT diet achieved lower W versus C. Rats fed high-fat vegetable oil diets showed similar effects on the zoometric parameters but differed in BF. BT showed the lowest lipid digestibility and BMC. In contrast, high vegetable oil diets produced no significant differences in BMC, BMC/W, BMD, spine BMD, and bone volume. Marked differences were observed for LO and BT groups in b-AP and CO and BT groups in bone volume. CONCLUSION: BT diet rich in saturated fatty acids had decreased digestibility and adversely affected energy and bone metabolisms, in growing healthy male rats. There were no changes in zoometric and bone parameters among rats fed high vegetable oil diets.
Assuntos
Desenvolvimento Ósseo , Osso e Ossos/metabolismo , Dieta Hiperlipídica/efeitos adversos , Metabolismo Energético , Gorduras/efeitos adversos , Óleos de Plantas/efeitos adversos , Fosfatase Alcalina/sangue , Animais , Osso e Ossos/química , Osso e Ossos/citologia , Bovinos , Óleo de Milho/efeitos adversos , Óleo de Milho/metabolismo , Digestão , Gorduras/metabolismo , Isoenzimas/sangue , Óleo de Semente do Linho/efeitos adversos , Óleo de Semente do Linho/metabolismo , Masculino , Minerais/análise , Óleos de Plantas/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Óleo de Soja/efeitos adversos , Óleo de Soja/metabolismo , DesmameRESUMO
Twenty-eight Angus (289 +/- 3.8 kg) steers were used in a completely randomized design to evaluate the effect of isocaloric supplementation of 2 different energy sources to steers rotationally grazing tall fescue pastures for 197 d in comparison to positive and negative controls. Steers were supplemented with either corn grain (0.52% BW on a DM basis; PC) or soybean hulls plus corn oil (0.45% BW on a DM basis + 0.10% BW on an as-fed basis; PO) using Calan gates for individual intake measurement. Negative, pasture only (PA), and positive, high-concentrate control diets (85% concentrate:15% roughage on DM basis; C) were also included in the study. Steers on PC, PO, and PA treatments were managed together under a rotational grazing system, whereas C steers were fed a high-concentrate diet for the final 113 d using Calan gates. Forage DMI and apparent DM and NDF digestibility for the grazing treatments were evaluated using Cr(2)O(5) and indigestible NDF as digesta markers. Energy supplementation decreased (P = 0.02) forage DMI (% of BW) with respect to PA, but not (P = 0.58) total DMI. There were no differences (P = 0.53) among grazing treatments on apparent total DM digestibility. However, NDF digestibility was less (P < or = 0.05) in PC than in PO and PA; the latter 2 treatments did not differ (P > 0.05). Overall ADG was greater (P < 0.01) in supplemented, regardless of type, than in nonsupplemented grazing treatments. During the final 113 d, ADG was greater (P < 0.01) in C than in the grazing treatments. Overall supplement conversion did not differ (P = 0.73) between supplement types and was less (P = 0.006) than C. Carcass traits did not differ (P > 0.05) between energy sources. Dressing percentage and HCW were greater (P < 0.01) in supplemented cattle than in PA. Fat thickness and KPH percentage for PA were less (P < 0.05) than for PO but did not differ (P > 0.14) from PC. Marbling score, LM area, and quality grade did not differ (P > 0.05) between grazing treatments. Hot carcass weight for C was heavier (P < 0.001) than for pastured cattle. Quality and yield grades of C carcasses were also greater (P < 0.001) than carcasses from pastured steers. Energy supplementation, regardless of source, to grazing steers increased ADG, dressing percentage, and carcass weight compared with PA steers; however, supplemented steers had less ADG, efficiency, dressing percentage, and carcass weight compared with high-concentrate finished steers.
Assuntos
Composição Corporal/fisiologia , Bovinos/fisiologia , Óleo de Milho/metabolismo , Suplementos Nutricionais , Digestão/fisiologia , Festuca/metabolismo , Zea mays/metabolismo , Ração Animal/análise , Ração Animal/economia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/crescimento & desenvolvimento , Bovinos/metabolismo , Óleo de Milho/administração & dosagem , Masculino , Distribuição Aleatória , Glycine max/metabolismo , Aumento de Peso/fisiologiaRESUMO
Low energy intake is one the most important factors related to nutritional wasting during diarrheal episodes and fat is the macronutrient with the highest energy value. So we intended to seek dietary fat sources, with the highest bioavailability during diarrheal episodes. Three basal (control) and three 42.8 lactose containing diets, used to induce diarrhea, were prepared with corn oil, butterfat or lard. The assay included 48 Sprague-Dawley rats, 28 d of age, initial weights of 65.5 +/- 5.2 g, distributed in 6 groups that received the diets during 15 d. The different types of fat did not affect diet intake, weight gain or fecal losses in rats without diarrhea (control). Low weight gain was found in rats with diarrhea regardless of the type of fat consumed and was related to low diet consumption. Mean fat absorption during diarrhea was as follows: butterfat 84, lard 87 and corn oil 91. The latter was related to lower fecal losses and higher fat absorption during the 15 d study. Considering that the three fat sources evaluated are easily purchased and widely accepted, and that nutritional management of subjects with diarrhea includes the intake of energy dense diets, it seems that the use of corn oil in these formulations could offer greater advantages.
Assuntos
Animais , Masculino , Ratos , Diarreia , Gorduras na Dieta , Absorção Intestinal/fisiologia , Manteiga , Diarreia , Gorduras na Dieta , Lactose , Óleo de Milho/metabolismo , Ratos Sprague-Dawley , SuínosRESUMO
Lipase (Glycerol ester hydrolase EC 3.1.1.3.) from a Brazilian strain of Fusarium solani FSI has been investigated. The effect of different carbon sources and trace elements added to basal medium was observed with the aim of improving enzyme production. Lipase specific activity was highest (0.45 U mg(-1)) for sesame oil. When this medium was supplemented with trace elements using olive oil, corn oil and sesame oil the lipase specific activity increased to 0.86, 1.89 and 1.64 U mg(-1), respectively, after 96 h cultivation without any considerable biomass increase. The Km of this lipase using pNPP (p-nitrophenylpalmitate) as substrate, was 1.8 mM with a Vmax of 1.7 micromol min(-1) mg protein(-1). Lipase activity increased in the presence of increasing concentrations of hexane and toluene. In contrast, incubation of this enzyme with water-soluble solvents decreased its activity after 10% concentration (v/v) of the solvent. The lipase activity was stable below 35 degrees C but above this temperature activity losses were observed.
Assuntos
Fermentação , Fusarium/enzimologia , Indústrias , Lipase/química , Reatores Biológicos , Óleo de Milho/metabolismo , Hexanos/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Lipase/metabolismo , Azeite de Oliva , Palmitatos/metabolismo , Óleos de Plantas/metabolismo , Óleo de Gergelim/metabolismo , Temperatura , Fatores de Tempo , Tolueno/metabolismoRESUMO
Low energy intake is one the most important factors related to nutritional wasting during diarrheal episodes and fat is the macronutrient with the highest energy value. So we intended to seek dietary fat sources, with the highest bioavailability during diarrheal episodes. Three basal (control) and three 42.8% lactose containing diets, used to induce diarrhea, were prepared with corn oil, butterfat or lard. The assay included 48 Sprague-Dawley rats, 28 d of age, initial weights of 65.5 +/- 5.2 g, distributed in 6 groups that received the diets during 15 d. The different types of fat did not affect diet intake, weight gain or fecal losses in rats without diarrhea (control). Low weight gain was found in rats with diarrhea regardless of the type of fat consumed and was related to low diet consumption. Mean fat absorption during diarrhea was as follows: butterfat 84%, lard 87% and corn oil 91%. The latter was related to lower fecal losses and higher fat absorption during the 15 d study. Considering that the three fat sources evaluated are easily purchased and widely accepted, and that nutritional management of subjects with diarrhea includes the intake of energy dense diets, it seems that the use of corn oil in these formulations could offer greater advantages.
Assuntos
Diarreia/metabolismo , Gorduras na Dieta/metabolismo , Animais , Manteiga , Óleo de Milho/metabolismo , Diarreia/induzido quimicamente , Diarreia/dietoterapia , Gorduras na Dieta/uso terapêutico , Absorção Intestinal/fisiologia , Lactose , Masculino , Ratos , Ratos Sprague-Dawley , SuínosRESUMO
Se evaluó el efecto de la ingestión de aceites de maíz, oliva o pescado, y de un suplemento de vitaminas antioxidantes, sobre la composición relativa en ácidos grasos de fosfolípidos hepáticos. Ratas macho Sprague Dawley se alimentaron durante 20 días con dietas semipurificadas que contienen 15 por ciento de aceite, sin o con suplementación vitamínica (50 mg/100 g dl alfa-tocoferilacetato y 3 mg/100 g ß-caroteno) (n= 6 animales por grupo). Al cabo del tratamiento dietario, se analizó el perfil de ácidos grasos de fosfatidilcolina (FC), fosfatidilserina + fosfatidinositol (FS + FI) y fosfatidiletanolamina (FE), observándose diferencia significativa en la proporción relativa de algunos ácidos grasos entre los distintos grupos experimentales. En general, los fosfolípidos de ratas alimentadas con aceite de oliva exhibieron mayor proporción de ácido oleico; la ingestión de aceite de maíz incrementó los niveles de ácido linoleico, y el aceite de pescado disminuyó la proporción de ácidos araquidónico y docosatetraenoico, a la vez que aumentó el contenido de ácidos eicosapentaenoico y docosahexaenoico en los fosfolípidos analizados. Con la ingestión de aceite de maíz con suplemento vitamínico aumentó el contenido de ácido oleico en FE, en tanto que con aceite de pescado con suplemento vitamínico aumentó la proporción de ácido oleico y disminuyó la de ácido araquidónico en FC. Los resultados demuestran que la composición relativa en ácidos grasos de fosfolípidos hepáticos es susceptible de ser modificada por el tipo de aceite ingerido en la dieta y, dentro de ciertos límites, por el consumo de suplementos de vitaminas antioxidantes
Assuntos
Animais , Ratos , Óleo de Milho/metabolismo , Ácidos Graxos Insaturados/química , Antioxidantes/metabolismo , Óleos de Peixe/metabolismo , Dieta Aterogênica , Vitaminas na Dieta/metabolismo , Alimentos Fortificados , Fosfolipídeos/química , Fígado/metabolismoRESUMO
Se estudió el efecto de la administración de aceite de maíz con la dieta sobre el metabolismo de los ácidos grasos esenciales (AGE) en lactantes normales y desnutridos alimentados solamente con leche de vaca desde el nacimiento. Se seleccionó también un grupo de lactantes alimentados con leche materna. Se usó como parámetro bioquímico para evaluar las condiciones en que se encontraban los AGE la composición en ácidos grasos de los fosfolípidos del plasma. Se observó un cuadro consistente con una carencia en AGE tanto en lactantes normales como desnutridos alimentados con leche de vaca, es decir, una disminución de la proporción de los ácidos grasos de la serie n6 y un aumento de los ácidos grasos saturados. Calculando la relación precursor-productos de los ácidos polietilénicos se observó una alteración del metabolismo del ácido linoleico. La administración del aceite de maíz restauró el perfil de los ácidos grasos a valores normales aun en los lactantes desnutridos a pesar de que el síndrome clínico de la desnutrición no había sido corregido
Assuntos
Recém-Nascido , Lactente , Humanos , Masculino , Feminino , Ácidos Graxos Essenciais/metabolismo , Desnutrição Proteico-Calórica/metabolismo , Leite/química , Óleo de Milho/metabolismo , Fosfolipídeos/metabolismo , Ácidos Graxos Essenciais/sangue , Ácidos Linoleicos/metabolismo , Cromatografia Gasosa , Alimentos Fortificados , Leite Humano/química , Óleo de Milho/análise , Fosfolipídeos/sangueRESUMO
Se estudió el efecto de la administración de aceite de maíz con la dieta sobre el metabolismo de los ácidos grasos esenciales (AGE) en lactantes normales y desnutridos alimentados solamente con leche de vaca desde el nacimiento. Se seleccionó también un grupo de lactantes alimentados con leche materna. Se usó como parámetro bioquímico para evaluar las condiciones en que se encontraban los AGE la composición en ácidos grasos de los fosfolípidos del plasma. Se observó un cuadro consistente con una carencia en AGE tanto en lactantes normales como desnutridos alimentados con leche de vaca, es decir, una disminución de la proporción de los ácidos grasos de la serie n6 y un aumento de los ácidos grasos saturados. Calculando la relación precursor-productos de los ácidos polietilénicos se observó una alteración del metabolismo del ácido linoleico. La administración del aceite de maíz restauró el perfil de los ácidos grasos a valores normales aun en los lactantes desnutridos a pesar de que el síndrome clínico de la desnutrición no había sido corregido (AU)
Assuntos
Recém-Nascido , Lactente , Estudo Comparativo , Humanos , Masculino , Feminino , Leite/química , Fosfolipídeos/metabolismo , Ácidos Graxos Essenciais/metabolismo , Desnutrição Proteico-Calórica/metabolismo , Óleo de Milho/metabolismo , Óleo de Milho/análise , Fosfolipídeos/sangue , Ácidos Graxos Essenciais/sangue , Ácidos Linoleicos/metabolismo , Alimentos Fortificados , Cromatografia Gasosa , Leite Humano/químicaRESUMO
Los aceites poseen una composición acil grasa característica, responsable de muchos de sus efectos biológicos, que pueden modificarse por la ingestión concomitante de colesterol. En el estudio se evaluó el efecto de la ingestión de aceites de maíz, avellana y pescado, y la suplementación con colesterol, sobre los niveles de lípidos plasmáticos y hepáticos. Ratas macho se alimentaron con dieta que contenía 15 por ciento de aceite, sin/con 1 por ciento colesterol, durante 20 días. El grupo con avellanas exhibió la mayor concentración plasmática de colesterol, p<0,001, en tanto que el grupo con aceite de pescado presentó los niveles más bajos, p<0,001. El grupo con maíz/colesterol exhibió menos concentración de HDL, p<0,001, la cual aumentó en el grupo con aceite de pescado/colesterol. El peso del hígado fue mayor en el grupo con maíz/colesterol, p<0,001. El colesterol indujo un incremento de los lípidos hepáticos en los grupos con aceites vegetales. Los lípidos hepáticos fueron más bajos al ingerir aceite marino/colesterol, p<0,001. Los resultados indican que el aceite de pescado indujo los niveles más bajos de lípidos en plasma, en tanto que el de avellana es hipercolesterolémico, mostrando estrecha relación entre las grasas dietarias (ácidos grasos y colesterol) y los lípidos plasmáticos y hepáticos