RESUMO

The influence of feeding a low protein diet to rat dams during gestation and lactation on lipid metabolism in pups was studied. Wistar rats were fed 5, 10, 15 and 25% dietary protein during gestation and lactation. Pup growth was monitored until weaning, and brain weight, protein concentration, proteolipid concentration and total lipid phosphorus concentration of brain were analyzed. The levels of fatty acids in dam milk as well as in pup liver phospholipids and brain prosphatidylcholine and phosphatidylethanolamine were determined. The progressive deprivation of maternal dietary protein produced a reduction in the total saturated fatty acid concentration of dam milk and an increment in the concentration of nonmetabolized linoleic acid. Pup body and brain weights as well as proteolipid, protein and total lipid phosphorus concentrations in brain were reduced in proportion to the degree of dietary protein deficiency. The products:precursor ratio of (n-6) fatty acids in liver phospholipids revealed an impairment in the elongation-desaturation pathway due to maternal protein deficiency. Both (n-6) and (n-3) polyunsaturated fatty acids within brain phosphatidylethanolamine were decreased by reduced maternal dietary protein intake, whereas only the linoleic acid-derived products were similarly affected in the corresponding phosphatidylcholine fraction. These results demonstrate the widespread and profound deleterious effects of low protein levels of maternal diet on the growth rate, brain development and fatty acid metabolism in rat pups.

Assuntos

Encéfalo/crescimento & desenvolvimento , Ácidos Graxos Essenciais/metabolismo , Lactação/fisiologia , Complicações na Gravidez/fisiopatologia , Desnutrição Proteico-Calórica/fisiopatologia , Análise de Variância , Animais , Animais Lactentes/crescimento & desenvolvimento , Química Encefálica , Dieta com Restrição de Proteínas , Desenvolvimento Embrionário e Fetal/fisiologia , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/metabolismo , Feminino , Fígado/química , Fígado/metabolismo , Leite/química , Tamanho do Órgão/fisiologia , Fosfatidilcolinas/análise , Fosfatidiletanolaminas/análise , Gravidez , Ratos , Ratos Wistar , Aumento de Peso/fisiologia

RESUMO

The effect of corn oil diet administration on the essential fatty acids (EFAs) profiles was evaluated in plasma phospholipids from normal and malnourished cow's milk fed infants nursing infants. A control group of only breast-fed was also selected for this study. The fatty acid composition was determined by gas-liquid chromatography and used as biochemical variable for evaluating EFA status. A fall in the proportion of fatty acids concomitant with an increase in the saturated fatty acids, consistent with a pattern of essential fatty acid deficiency (EFAD) was observed in the cow's milk fed infants, either normal or malnourished (Table 2). The corn oil administration was capable of restoring the fatty acid profile to normal values, similar to the values of the control group of breast-fed infants, even in malnourished infants, although during the 15 days test they did not correct their clinical syndrome of malnutrition (Table 3). Calculation of the product-precursor of the linoleic acid provided evidence for the positive effect of the corn oil administration.

Assuntos

Óleo de Milho/farmacologia , Ácidos Graxos Essenciais/análise , Fosfolipídeos/sangue , Desnutrição Proteico-Calórica/metabolismo , Animais , Feminino , Alimentos Fortificados , Humanos , Lactente , Recém-Nascido , Ácidos Linoleicos/metabolismo , Masculino , Leite/química , Leite Humano/química

RESUMO

The effect of corn oil diet administration on the essential fatty acids (EFAs) profiles was evaluated in plasma phospholipids from normal and malnourished cows milk fed infants nursing infants. A control group of only breast-fed was also selected for this study. The fatty acid composition was determined by gas-liquid chromatography and used as biochemical variable for evaluating EFA status. A fall in the proportion of fatty acids concomitant with an increase in the saturated fatty acids, consistent with a pattern of essential fatty acid deficiency (EFAD) was observed in the cows milk fed infants, either normal or malnourished (Table 2). The corn oil administration was capable of restoring the fatty acid profile to normal values, similar to the values of the control group of breast-fed infants, even in malnourished infants, although during the 15 days test they did not correct their clinical syndrome of malnutrition (Table 3). Calculation of the product-precursor of the linoleic acid provided evidence for the positive effect of the corn oil administration.

RESUMO

The effect of a low protein diet during pregnancy and lactation on the fatty acid composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from brains of ten-day-old rats was studied. The results indicated that partial deprivation of protein during early development was associated with an increase in the fatty acids of the n-9 family in PC. The fatty acids of the linoleic acid series decreased in PE but were not modified in PC. These minor changes did not affect the double bond index values either in PC or in PE. The effect of protein depletion on the in vivo metabolic transformation of intracraneally injected [1-14C]linoleic and [1-14C]alpha-linolenic acids was also studied. The percentage distribution of the labeled precursors and their derivatives among PC and PE differed from that of mass distribution. These results indicate that the direct uptake of polyunsaturated fatty acids from the blood and/or the low turnover rate of these acids incorporated into PC and PE might be involved in maintaining the fatty acid pattern of these brain lipids.

Assuntos

Encéfalo/metabolismo , Ácidos Linoleicos/metabolismo , Ácidos Linolênicos/metabolismo , Complicações na Gravidez , Deficiência de Proteína/metabolismo , Envelhecimento/metabolismo , Animais , Animais Recém-Nascidos/metabolismo , Animais Lactentes/metabolismo , Embrião de Mamíferos/metabolismo , Ácidos Graxos/análise , Feminino , Injeções Intraventriculares , Ácido Linoleico , Masculino , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Gravidez , Ratos , Ácido alfa-Linolênico

RESUMO

The effects of the n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the growth of a human lung mucoepidermoid carcinoma (HLMC) in athymic mice were studied. The mice were divided into three groups which were given either a control chow diet (C), a chow diet supplemented with EPA/DHA (P) (25 or 50 mg of free n-3 fatty acids/g of pellet/day), or chow diet supplemented with palmitic acid (S) (isocaloric with P). Two independent experimental schedules were followed: i) host mice bearing either tumors that were allowed to reach 4000 mm3, or only 35 mm3, were fed C, P or S for 21 or 41 days; ii) animals were fed C, P and S for 9 days before tumor implant and were maintained on these diets throughout tumor growth. Food consumption, mouse weight and liver/body weight ratio showed no significant differences between supplemented diets and chow. Tumor growth was markedly inhibited (45%) in both experiments by the EPA/DHA supplemented diet. In Experiment 2, only 60% of mice fed diet P had tumors. The fatty acid composition of neutral and polar lipids of host liver and tumor reflected the dietary intake of n-3 fatty acids; the content of arachidonic acid was reduced by 50%, and EPA/DHA was increased 3- to 5-fold. Tumor prostaglandin E2 levels were reduced 7.4-fold in the P group. The reduced PGE2 content may be a factor in tumor growth inhibition.

Assuntos

Carcinoma/etiologia , Dinoprostona/metabolismo , Ácidos Graxos Ômega-3/farmacologia , Óleos de Peixe/farmacologia , Neoplasias Pulmonares/etiologia , Animais , Ácido Araquidônico/metabolismo , Gorduras na Dieta/farmacologia , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Ácidos Graxos/metabolismo , Fígado/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus

RESUMO

The influence of severe protein-calorie malnutrition on essential fatty acid (EFA) status was evaluated in nursing infants aged 2-5 mo. A control group of the same age and with normal weight-for-height was also selected for this study. The fatty acid pattern of total phospholipids from plasma and red blood cells (RBCs) was determined and then used as a biochemical variable for evaluating EFA status. A sharp fall in the relative percentage of n-6 (omega-6) fatty acids concomitant with an increase in the n-9 fatty acids in plasma and RBC phospholipids was observed. These results are consistent with the picture of EFA deficiency and showed that the deficiency state is well correlated with the severity of malnutrition. Calculation of the product-precursor ratio of polyunsaturated fatty acids derived from linoleic acid (18:2n-6) in RBC phospholipids provides evidence for an impairment in the elongation-desaturation pathway promoted by the protein-calorie malnutrition.

Assuntos

Aleitamento Materno , Ácidos Graxos Essenciais/deficiência , Desnutrição Proteico-Calórica/metabolismo , Eritrócitos/metabolismo , Ácidos Graxos Essenciais/sangue , Ácidos Graxos Insaturados/sangue , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fosfolipídeos/sangue

RESUMO

The capacity to synthesize both prostaglandins E1 (PGE1) and E2 (PGE2) has been determined in human lung mucoepidermoid carcinoma homogenates when [14C]-fatty acid precursors were added to the incubation medium. Only 10% of the total radioactivity recovered in PGs was found in PGF1 alpha and PGF2 alpha. The experiments were principally focused to inhibit the PGE2 synthesis either with pure eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids or with mixtures of both n-3 fatty acids obtained from fish oil. The results demonstrated that significant inhibitions were found when using 25 microM or a higher concentration of pure EPA or DHA in the incubation medium; however, 5 microM of mixtures of different EPA/DHA ratio caused the same inhibition. The results suggest that EPA and DHA, when added together, may enforce their inhibitory effect on PGE2 synthesis.

Assuntos

Carcinoma/metabolismo , Dinoprostona/biossíntese , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Neoplasias Pulmonares/metabolismo , Animais , Óleos de Peixe/farmacologia , Humanos , Técnicas In Vitro , Camundongos , Camundongos Nus , Transplante de Neoplasias

RESUMO

Since tumor cells show abnormal fatty acid composition, it is likely that their desaturase systems were affected to some extent. Although desaturase activities in experimental tumors have been evaluated, to our knowledge, fatty acid desaturases in human neoplasms and particularly in human tumors grown in nude mice have not been assessed yet. We have therefore, chosen a rapidly growing human lung mucoepidermoid carcinoma (HLMC) grown in nude mice to study microsomal fatty acid desaturation and chain elongation activities. Tumor microsomal proteins were incubated with unlabeled malonyl-CoA and one of the following fatty acids: [1-14C]palmitic (16:0), [1-14C]linoleic (18:2), alpha-[1-14C]linolenic (alpha-18:3), and unlabeled gamma-linolenic (gamma-18:3) plus [2-14C]malonyl-CoA. Data show that HLMC microsomes were capable to desaturate 16:0, alpha-18:3, and dihomogammalinolenic acids (20:3) by delta 9, delta 6 and delta 5 desaturase, respectively; however, delta 6 desaturase activity on [14C]18:2 was not detected. The microsomal elongation system was active in all fatty acid series tested except for 18:2. These findings show that the undetectable activity for 18:2 desaturation is not exclusively found in experimental tumors.

Assuntos

Carcinoma/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Ácidos Graxos Insaturados/metabolismo , Neoplasias Pulmonares/metabolismo , Microssomos/metabolismo , Animais , Radioisótopos de Carbono , Linhagem Celular , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Transplante Heterólogo

RESUMO

The contribution of the acyl specificity of post heparin lipolytic enzymes to changes in the plasma free fatty acid (FFA) pattern during very low density lipoproteins (VLDL) lipolysis, was studied. The effect of these changes in the 3H-choline incorporation into platelet phosphatidylcholine (PC) during incubation, was also investigated. "In vitro" experiments with post heparin plasma and isolated VLDL showed an increase of 61.1 in the percentage of linoleic acid (C 18:2) concomitant with a decrease of 57.1% in the relative concentration of stearic acid (C 18:0) during VLDL triacylglycerol lipolysis. Similarly, a decrease of 39.2% in the plasma concentration of C 18:0 and an increase of 29.4% in the C 18:2 and 9.6% in the oleic acid (C 18:1) concentration were observed after intravenous injection of low doses of heparin. The plasma FFA compositional changes that occur during "in vitro" VLDL lipolysis accelerate not only the incorporation of labeled choline but also the incorporation of C 18:2 into platelet PC. It is suggested that the above observed changes on platelet response are due to the increase in the C 18:2 concentration during incubation.

Assuntos

Plaquetas/metabolismo , Ácidos Graxos não Esterificados/sangue , Heparina/farmacologia , Lipólise/efeitos dos fármacos , Lipoproteínas VLDL/sangue , Fosfatidilcolinas/sangue , Adulto , Plaquetas/efeitos dos fármacos , Colina/sangue , Humanos , Técnicas In Vitro , Cinética , Fosfatidilcolinas/biossíntese , Valores de Referência

RESUMO

Tumor lipids were studied in the experimental model Human Lung Carcinoma/nude mice as well as the effect of this human neoplasm on the host liver lipid metabolism. Fatty acid profiles from tumoral lipids revealed the loss of specificity for fatty acid composition in triglycerides. Host liver fatty acid composition and cholesterol metabolism were affected by the implanted human lung tissue. A noticeable increase ratio between saturated/unsaturated fatty acids was observed in host liver fatty acid phospholipids (1.17 +/- 0.17) in comparison to control liver (0.84 +/- 0.04). Cholesterol synthesis was assessed "in vivo" by means of [14C]acetate incorporation. The specific radioactivity of [14C] cholesterol was increased by a factor of about 6 in host liver as compared with control liver. This observation along with the marked decrease in the cholesterol content of host liver and the hypocholesterolemia detected in the host mice led us to suggest an increase in the liver cholesterol catabolism promoted by the presence of the tumor.

Assuntos

Metabolismo dos Lipídeos , Neoplasias Hepáticas/metabolismo , Fígado/metabolismo , Animais , Colesterol/metabolismo , Modelos Animais de Doenças , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Feminino , Humanos , Neoplasias Hepáticas/análise , Camundongos , Camundongos Nus , Transplante de Neoplasias , Fosfolipídeos/metabolismo , Transplante Heterólogo , Triglicerídeos/metabolismo

RESUMO

Fatty acid patterns of major classes of lipids of serum were measured in forty Argentine children ages 2 to 24 months admitted to the hospital with chronic malnutrition. A normal control group of 48 children from the same population was also examined. Serum lipids were extracted and separated into phospholipids, cholesteryl esters, triglycerides, and free fatty acids. These were converted to methyl esters which were analyzed by gas chromatography. In chronic malnutrition, the fatty acid patterns of phospholipids and cholesteryl esters indicated changes characteristic of essential fatty acid deficiency of moderate degree. The total omega 6 acids were found to be highly significantly diminished from normal, and the ratio of 20:3 omega 9/20:4 omega 6 was highly significantly increased. Decreased proportions of omega 6 metabolites suggested impaired desaturase activity, and elevated ratios of 22:4 omega 6/20:4 omega 6 and 20:2 omega 6/18:2 omega 6 suggested increased chain elongation in chronic malnutrition.

Assuntos

Ácidos Graxos Essenciais/deficiência , Lipídeos/sangue , Desnutrição Proteico-Calórica/complicações , Argentina , Pré-Escolar , Ésteres do Colesterol/sangue , Ácidos Graxos/sangue , Feminino , Humanos , Lactente , Transtornos da Nutrição do Lactente/complicações , Masculino , Fosfolipídeos/sangue , Desnutrição Proteico-Calórica/sangue , Triglicerídeos/sangue

RESUMO

Pregnant rats were kept throughout gestation on a control diet (i.e., 25% protein), on a low protein diet (i.e., 5% protein) or on a fat-free diet. At 20-21 days of gestation, the rate of 9-, 6-, and 5-desaturation was measured, using microsomes from maternal and fetal livers and placenta microsomes. The effect of protein malnutrition was more evident upon Δ6-desaturase activity from maternal liver, while a less severe reduction in the activities of Δ9- and Δ5-desaturases was observed. No measurable activities of Δ5- and Δ6-desaturases were observed in fetal liver and placenta, while a low activity of Δ9-desaturase was detected in both tissues from the three groups under study. We concluded that Δ6-desaturation is greatly affected by maternal protein deprivation, and this fact could affect the normal supply of polyunsaturated fatty acids for the normal fetus growth and tissue development.