RESUMO
Metabolic syndrome has become a global health challenge and was recently reported to be positively correlated with increased sucrose consumption. Mechanistic analyses of excess sucrose-induced progression of metabolic syndrome have been focused mainly on abnormal hepatic lipogenesis, and the exact contribution of excess sucrose to metabolic disorders remains controversial. Considering that carbohydrate and lipid metabolisms exhibit clear circadian rhythms, here we investigated the possible contribution of diurnal oscillations to responses of hepatic lipid metabolism to excess sucrose. We found that excess sucrose dose-dependently promotes fatty liver and hyperlipidemia in in rats fed a high-sucrose diet (HSD). We observed that excess sucrose enhances the oscillation amplitudes of the expression of clock genes along with the levels of hepatic lipid and carbohydrate metabolism-related mRNAs that increase lipogenesis. We did not observe similar changes in the levels of the transcription factors regulating the expression of these genes. This suggested that the excess sucrose-induced, circadian rhythm-dependent amplification of lipogenesis is post-transcriptionally regulated via the stability of metabolic gene transcripts. Of note, our findings also provide evidence that fructose causes some of the HSD-induced, circadian rhythm-dependent alterations in lipogenic gene expression. Our discovery of HSD-induced circadian rhythm-dependent alterations in lipogenesis at the post-transcriptional level may inform future studies investigating the complex relationships among sucrose uptake, circadian rhythm, and metabolic enzyme expression. Our findings could contribute to the design of chrono-nutritional interventions to prevent or manage the development of fatty liver and hyperlipidemia in sucrose-induced metabolic syndrome.
Assuntos
Ritmo Circadiano , Sacarose Alimentar/efeitos adversos , Fígado Gorduroso/genética , Fígado/fisiopatologia , Síndrome Metabólica/genética , Animais , Sacarose Alimentar/metabolismo , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Humanos , Lipogênese , Fígado/metabolismo , Masculino , Síndrome Metabólica/etiologia , Síndrome Metabólica/metabolismo , Síndrome Metabólica/fisiopatologia , Ratos , Ratos WistarRESUMO
We have shown that intake of sesame seed and its lignan increases vitamin E concentrations and decreases urinary excretion levels of vitamin E metabolites in male Wistar rats, suggesting inhibition of vitamin E catabolism by sesame lignan. The aim of this study was to examine whether dietary sesame seed also increased vitamin K concentrations, because its metabolic pathway is similar to that of vitamin E. To test the effect of sesame lignan on vitamin K concentrations, male Wistar rats were fed a control diet or a diet with 0.2% sesamin (a sesame lignan) for 7 d in experiment 1. Liver phylloquinone (PK), menaquinone-4 (MK-4), and γ-tocopherol were greater in rats fed sesamin than in control rats. To test the effect of sesame seed on vitamin K concentrations, male Wistar rats were fed a control diet or a diet with 1, 5, or 10% sesame seed for 3 d in experiment 2. Liver and kidney PK and γ-tocopherol but not MK-4 were greater in rats fed sesame seed than in control rats, although differences in dietary amounts of sesame seed did not affect the PK concentrations. For further confirmation of the effect of sesame seed, male Wistar rats were fed a control diet or a diet with 20% sesame seed for 40 d in experiment 3. Kidney, heart, lung, testis, and brain PK and brain MK-4 were greater in rats fed sesame seed than in control rats. The present study revealed for the first time, to our knowledge, that dietary sesame seed and sesame lignan increase not only vitamin E but also vitamin K concentrations in rat tissues.
Assuntos
Dieta , Dioxóis/administração & dosagem , Lignanas/administração & dosagem , Sesamum/química , Vitamina K 1/análise , gama-Tocoferol/análise , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Dioxóis/química , Coração/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismo , Lignanas/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Ratos , Ratos Wistar , Sementes/química , Testículo/efeitos dos fármacos , Testículo/metabolismo , Vitamina K 1/metabolismo , Vitamina K 2/análogos & derivados , Vitamina K 2/análise , Vitamina K 2/metabolismo , gama-Tocoferol/metabolismoRESUMO
Recent reports have associated the use of social networking sites (SNS) with the drive for thinness in young women; however, its influence on their actual body shape and eating behaviors (EB) remains unclear. We aimed to examine the effect of SNS use on body mass index (BMI), body image (BI), and EB in young women. Participants included 196 healthy women (20-29 years) who answered questions about their SNS use, height, weight, BI and EB via a web-based survey. First, the correlation between time spent on SNS and each variable was determined. Participants were then divided into quartiles according to the duration of daily SNS use as long (≥3 h, n = 52) and short (<1 h, n = 54), and the data were then compared between the groups. Correlation analysis showed that the longer the duration of daily SNS use, the significantly lower the BMI, the use of nutrition labels, and the frequency of consumption of milk and dairy products. The long group had significantly lower BMI and ideal BI than the short group. The results suggest that spending more time on SNS in young women may be associated with thinner actual and ideal body shapes and poorer access to health information and healthy foods.
Assuntos
Imagem Corporal , População do Leste Asiático , Comportamento Alimentar , Uso da Internet , Rede Social , Magreza , Feminino , Humanos , Imagem Corporal/psicologia , Índice de Massa Corporal , População do Leste Asiático/psicologia , Comportamento Alimentar/psicologia , Somatotipos , Adulto Jovem , Adulto , Aparência Física , Magreza/psicologia , Inquéritos e Questionários , Acesso a Alimentos Saudáveis , Informação de Saúde ao Consumidor , Fatores de TempoRESUMO
Skipping breakfast is an irregular feeding behavior, typically in young people. In our previous study, we established a 4 h-delayed feeding protocol for rats as a breakfast-skipping model and showed that the 4 h-delayed feeding of a high-fat diet led to body weight gain in rats. Excess sucrose induces metabolic syndrome and fatty liver. Recently, excess sucrose intake has received increased attention. Young people generally consume more sugar than adults do. In the present study, we investigated whether a 4 h-delayed feeding promoted high-sucrose diet-induced abnormalities in lipid metabolism, such as fatty liver and obesity in rats. The 4 h-delayed feeding rats showed increased body weight gain, although it did not induce fatty liver and hyperlipidemia compared to normal feeding rats. Serum insulin concentration during the feeding period was higher than in the control rats, suggesting that slight insulin resistance was induced by the 4 h-delayed feeding. The surge in body temperature was also delayed by 4 h in response to the 4 h-delayed feeding. This delay would result in less energy expenditure to increase body weight. The oscillations of hepatic lipid and glucose metabolism-related gene expression were delayed by almost 2-4 h, and the clock genes were delayed by approximately 2 h. The 4 h-delayed feeding induced weight gain by affecting body temperature, insulin resistance, and circadian oscillation of lipid metabolism-related genes in rats fed a high-sucrose diet, suggesting that a high sucrose intake with breakfast skipping leads to obesity.
Assuntos
Fígado Gorduroso , Resistência à Insulina , Ratos , Animais , Ritmo Circadiano , Sacarose/efeitos adversos , Sacarose/metabolismo , Temperatura Corporal , Aumento de Peso , Metabolismo dos Lipídeos , Fígado/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/metabolismo , Peso Corporal , LipídeosRESUMO
Development of an accurate and efficient dietary method is required for national nutrition surveys. Some countries conduct dietary surveys and combine 24-h dietary records or 24-h dietary recalls with dietary questionnaires. This scoping review aimed to summarize studies that used results from national surveys that combined detailed dietary surveys (dietary records or 24-h dietary recall) and dietary questionnaires and identify the purpose of combining the two methods. The PubMed database and manual searches were used for the literature review. We extracted 58 articles from 16 national nutrition surveys from 14 countries. Most studies used 24-h dietary recall for detailed dietary surveys and the food frequency questionnaire (FFQ) or food propensity questionnaire (FPQ) for questionnaire surveys. Among 37 studies from eight countries, the purpose of combining the two dietary survey methods was to estimate energy and nutrient intakes from detailed dietary surveys and habitual food intake from questionnaires. These findings are useful as a reference when introducing new dietary survey methods in future national nutrition surveys.
Assuntos
Dieta , Ingestão de Alimentos , Registros de Dieta , Inquéritos e Questionários , Inquéritos Nutricionais , Rememoração Mental , Reprodutibilidade dos Testes , Inquéritos sobre Dietas , Ingestão de EnergiaRESUMO
For athletes, it is important to acquire lean body mass (LBM) involving the skeletal muscle mass during their growth periods; however, the influence of chronotype on LBM gain remains unclear. We therefore aimed to investigate whether chronotype, sleep-wake cycle on weekdays (SWC-W), and their interaction contribute to LBM gain among adolescent male athletes in a 4-month intervention study. The participants were 45 male high-school baseball players. The intervention, including exercise menu (running and muscle strength training) and nutritional education, was conducted during a 4-month period of season-off training. The chronotype, body composition, lifestyle, and dietary intake were investigated before intervention (baseline) and after 4 months. Among the participants [Morningness (n = 14), Eveningness (n = 15), Intermediate (n = 16); ME score based on the Morningness/Eveningness Scale for Children (MES-C)], the midpoint of sleep on weekdays (MSW) was calculated in the "Morningness" and "Eveningness" participants, respectively. They were divided into 4 groups based on a match/mismatch with the chronotype: Type M-match (n = 8), Type M-mismatch (n = 6), Type E-match (n = 7), and Type E-mismatch (n = 8) groups. The data were compared among the 4 groups. Moreover, multiple regression analysis was conducted using an increase (kg) LBM gain as a response variable. When comparing the data between the "Morningness" and "Eveningness" participants, there were no differences in nutrient intake, the duration of training, or each parameter of body composition (per body weight) at baseline or after 4 months. There were also no differences in the rates of change in the body weight or each parameter of body composition. In groups in which the chronotype was consistent with the SWC-W (the Type M-match and Type E-match groups), the LBM gain were slightly greater than in the Type M-mismatch and Type E-mismatch groups (Type M-match: 3.5 ± 2.0 kg, Type M-mismatch: 1.6 ± 1.7 kg, Type E-match: 3.4 ± 2.2 kg, and Type E-mismatch: 1.2 ± 1.8 kg, p = .057). Multiple regression analysis revealed that an extent of the LBM gain was associated with a match between the chronotype and SWC-W (ß = 0.37, p = .030), independent of a long duration of training (ß = 0.52, p = .004). The results suggested that training-related LBM gain is associated with interactions between the chronotype and SWC-W in adolescent male athletes.Abbreviations: LBM: Lean body mass; SWC-W: Sleep-wake cycle on weekdays; ME score: Morningness-eveningness score; MES-C: Morningness/Eveningness Scale for Children; MSW: Midpoint of sleep on weekdays; MSF: Midpoint of sleep on free days; MSFsc: Midpoint of sleep on free days corrected for sleep debt accumulated through weekdays.
Assuntos
Beisebol , Ritmo Circadiano , Adolescente , Composição Corporal , Peso Corporal , Criança , Ritmo Circadiano/fisiologia , Humanos , Masculino , Sono/fisiologia , Inquéritos e QuestionáriosRESUMO
Background: To investigate whether shifted timing of eating, breakfast skipping, induces alterations in the circadian clock and abnormal lipid metabolism, we have established a delayed meal timing (DMT) protocol for rats, which started eating food 4 h delay. In the present study, control and DMT rats were fed a high-cholesterol diet during zeitgeber time (ZT) 12-24 and ZT 16-4, respectively. The DMT protocol increased the hepatic lipids and epididymal adipose tissue weight without changes in food intake and body weight. The surge in body temperature was delayed by 4 h in the DMT group, suggesting that energy expenditure was decreased in response to DMT. The peaks of the diurnal rhythm of serum non-esterified fatty acids and insulin were delayed by 2 and 4 h due to DMT, respectively. The oscillation peaks of hepatic de novo fatty acid synthesis gene expression was delayed by 4 h in response to DMT, whereas the peak of hepatic clock genes were 2 h delayed or not by DMT. Although metabolic oscillation is considered to be controlled by clock genes, the disintegration rhythms between the clock genes and lipid metabolism-related genes were not observed in rats fed a high-fat diet in our previous study. These data suggest that the circadian rhythm of de novo fatty acid metabolism is regulated by timing of eating, but is not directly controlled by clock genes. The present study suggests that breakfast skipping would complicate fatty liver and body fat accumulation.
RESUMO
Excess sucrose intake has been found to be a major factor in the development of metabolic syndrome, especially in promoting nonalcoholic fatty liver disease. The excess fructose is believed to targets the liver to promote de novo lipogenesis, as described in major biochemistry textbooks. On the contrary, in this study, we explored the possible involvement of gut microbiota in excess sucrose-induced lipid metabolic disorders, to validate a novel mechanism by which excess sucrose causes hepatic lipid metabolic disorders via alterations to the gut microbial community structure. Wistar male rats were fed either a control starch diet or a high-sucrose diet for 4 weeks. Half of the rats in each group were treated with an antibiotic cocktail delivered via drinking water for the entire experimental period. After 4 weeks, rats fed with the high-sucrose diet showed symptoms of fatty liver and hyperlipidemia. The architecture of cecal microbiota was altered in rats fed with high-sucrose diet as compared to the control group, with traits including increased ratios of the phyla Bacteroidetes/Firmicutes, reduced α-diversity, and diurnal oscillations changes. Antibiotic administration rescued high-sucrose diet-induced lipid accumulation in the both blood and liver. Levels of two microbial metabolites, formate and butyrate, were reduced in rats fed with the high-sucrose diet. These volatile short-chain fatty acids might be responsible for the sucrose-induced fatty liver and hyperlipidemia. Our results indicate that changes in the gut microbiota induced by a high-sucrose diet would promote the development of nonalcoholic fatty liver disease via its metabolites, such as short-chain fatty acids.
Assuntos
Sacarose Alimentar/efeitos adversos , Disbiose/induzido quimicamente , Microbioma Gastrointestinal/efeitos dos fármacos , Hiperlipidemias/induzido quimicamente , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , DNA Bacteriano/genética , Sacarose Alimentar/administração & dosagem , Regulação da Expressão Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , RatosRESUMO
Using rats, we previously found that vitamin C deficiency increases serum levels of interleukin-6 (IL-6) and glucocorticoid, and changes the gene expression of acute phase proteins (APP) in the liver. However, it remains unclear how vitamin C deficiency causes these inflammation-like responses. In this study, we investigated the possibility that changes in gut microbiota are involved in the induction of APP gene expression by vitamin C deficiency. ODS rats that cannot genetically synthesize vitamin C were divided into 4 groups based on the presence or absence of vitamin C or antibiotics and were raised for 15 d. Neomycin, vancomycin, and ampicillin were used as antibiotics, and 300 mg L-ascorbic acid/kg was added to the AIN93G diet. Vitamin C deficiency affected neither the wet tissue weights nor relative abundance of bacteria in the cecal contents. Antibiotic administration increased wet weights of the cecum, cecal contents, and colon, changed the relative abundance of some bacteria in the cecal contents, and decreased serum IL-6 level. However, antibiotic administration had no effect on serum concentrations of corticosterone and α1-acid glycoprotein (AGP), vitamin C concentration in the liver, and mRNA levels of haptoglobin and AGP in the liver. Therefore, disturbance of gut microbiota did not attenuate the increase in glucocorticoid level and induction of APP gene expression due to vitamin C deficiency. This suggests that gut microbiota is not involved in the inflammation-like responses caused by vitamin C deficiency.
Assuntos
Proteínas de Fase Aguda/metabolismo , Deficiência de Ácido Ascórbico/metabolismo , Microbioma Gastrointestinal/fisiologia , Proteínas de Fase Aguda/análise , Animais , Antibacterianos/farmacologia , Ácido Ascórbico/análise , Ácido Ascórbico/metabolismo , Corticosterona/sangue , Corticosterona/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Inflamação/metabolismo , Interleucina-6/sangue , Interleucina-6/metabolismo , Fígado/química , Fígado/metabolismo , Masculino , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , RatosRESUMO
Excessive sucrose intake, known as fructose toxicity, leads to fatty liver, hyperlipidemia, and metabolic syndrome. Circadian disorders also contribute to metabolic syndrome. Here, we investigated the effect of excessive sucrose intake on circadian rhythms of the small intestine, the main location of sucrose absorption, to elucidate a mechanism of sucrose-induced abnormal lipid metabolism. Male Wistar rats were fed control starch or high-sucrose diets for 4 weeks. High-sucrose diet-induced fatty liver and hypertriglyceridemia in rats. Amplitudes of PER1/2 expression oscillations in the small intestine were reduced by excessive sucrose, while gene expression of GLUT5 and gluconeogenic enzymes was enhanced. These changes would contribute to interfering in lipid homeostasis as well as adaptive responses to control fructose toxicity in rats.
Assuntos
Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/fisiologia , Sacarose Alimentar/farmacologia , Intestino Delgado/efeitos dos fármacos , Animais , Peso Corporal/fisiologia , Dieta/efeitos adversos , Sacarose Alimentar/metabolismo , Intestino Delgado/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Síndrome Metabólica/metabolismo , Ratos WistarRESUMO
The etiology of metabolic syndrome involves several complicated factors. One of the main factors contributing to metabolic syndrome has been proposed to be excessive intake of sucrose, which disturbs hepatic lipid metabolism, resulting in fatty liver. However, the mechanism by which sucrose induces fatty liver remains to be elucidated. Considering feeding behavior important for metabolism, we investigated whether time-restricted feeding of high sucrose diet (HSD), only in the active phase (the dark phase of the daily light/dark cycle), would ameliorate adverse effects of sucrose on lipid homeostasis in rats. Male Wistar rats, fed either an ad libitum (ad lib.) or time-restricted control starch diet (CD) or HSD were investigated. Rats fed ad lib. (CD and HSD) completed approximately 20% of food intake in the daytime. Time-restricted feeding did not significantly suppress total food intake of rats. However, time-restricted feeding of HSD significantly suppressed the increased plasma triglyceride levels. Moreover, time-restricted feeding also ameliorated HSD-induced liver lipid accumulation, whereas circadian oscillations of liver clock gene or transcriptional factor gene expression for lipid metabolism were not altered significantly. These results demonstrated that restricting sucrose intake only during the active phase in rats ameliorates the abnormal lipid metabolism caused by excess sucrose intake.
Assuntos
Carboidratos da Dieta/efeitos adversos , Fígado Gorduroso , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Síndrome Metabólica , Sacarose/efeitos adversos , Animais , Ritmo Circadiano/efeitos dos fármacos , Carboidratos da Dieta/farmacologia , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Fígado Gorduroso/fisiopatologia , Comportamento Alimentar/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/patologia , Masculino , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Síndrome Metabólica/fisiopatologia , Ratos , Ratos Wistar , Sacarose/farmacologia , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacosRESUMO
The circadian clock is closely related to human health, such as metabolic syndrome and cardiovascular disease. Our previous study revealed that irregular feeding induced abnormal lipid metabolism with disruption of the hepatic circadian clock. We hypothesized that breakfast skipping induces lipid abnormalities, such as adiposity, by altering the hepatic circadian oscillation of clock and lipid metabolism-related genes. Here, we established a delayed first active-phase meal (DFAM) protocol as a breakfast-skipping model. Briefly, rats were fed a high-fat diet during zeitgeber time (ZT) 12-24 in a control group and ZT 16-4 in the DFAM group. The DFAM group showed increased body weight gain and perirenal adipose tissue weight without a change in total food intake. The circadian oscillations of hepatic clock and de novo fatty acid synthesis genes were delayed by 2-4 h because of DFAM. The peaks of serum insulin, a synchronizer for the liver clock, bile acids, and non-esterified fatty acid (NEFA) were delayed by 4-6 h because of DFAM. Moreover, DFAM delayed the surge in body temperature by 4 h and may have contributed to the increase in body weight gain and adipose tissue weight because of decreased energy expenditure. These data indicated a potential molecular mechanism by which breakfast skipping induces abnormal lipid metabolism, which is related to the altered circadian oscillation of hepatic gene expression. The results also suggested that the delayed peaks of serum NEFA, bile acids, and insulin entrain the circadian rhythm of hepatic clock and lipid metabolism-related genes.
Assuntos
Peso Corporal/fisiologia , Ritmo Circadiano/fisiologia , Dieta Hiperlipídica , Comportamento Alimentar/fisiologia , Metabolismo dos Lipídeos/fisiologia , Refeições , Adiposidade/fisiologia , Animais , Ácidos e Sais Biliares/sangue , Glicemia , Ácidos Graxos não Esterificados/sangue , Insulina/sangue , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar , Aumento de PesoRESUMO
We have reported that vitamin E intake lowers phylloquinone (PK) concentration in extrahepatic tissues of rats. In this study, we aimed to clarify the characteristic of the distribution of menaquinone-7 (MK-7), a vitamin K contained in fermented foods, by comparison with other vitamin K distributions and to clarify the effect of vitamin E intake on MK-7 concentration in rats. Rats were fed a vitamin K-free diet (Free group), a diet containing 0.75 mg PK/kg (PK group), a 0.74 mg menaquinone-4 (MK-4)/kg diet (MK-4 group), a 1.08 mg MK-7/kg diet (MK-7 group), or a 0.29 mg menadione (MD)/kg diet (MD group) for 16 wk. MK-7 mainly accumulated in the liver, spleen, and adrenal gland of the MK-7 group, although PK accumulated in the serum and all tissues of the PK group. Conversely, MK-4 was present in all tissues of the PK, MK-4, MK-7, and MD groups. MK-4 concentration in the serum, liver, adipose tissue, and spleen was higher in the MK-4 group than in the other groups; however, MK-4 concentration in the kidney, testis, tibia, and brain was lower in the MK-4 group than in the PK, MK-7, and MD groups. Next, vitamin E- and K-deficient rats were orally administered MK-7 with or without α-tocopherol. α-Tocopherol did not affect MK-7 or MK-4 concentration in the serum and various tissues. These results suggested that MK-7 is particularly liable to accumulate in the liver, and MK-7 concentration is not affected by vitamin E intake.
Assuntos
Fígado/efeitos dos fármacos , Estado Nutricional/efeitos dos fármacos , Vitamina K 2/análogos & derivados , alfa-Tocoferol/farmacologia , Animais , Dieta , Alimentos Fermentados , Fígado/metabolismo , Masculino , Ratos Wistar , Distribuição Tecidual , Vitamina K 1/metabolismo , Vitamina K 1/farmacocinética , Vitamina K 2/metabolismo , Vitamina K 2/farmacocinética , Vitamina K 3/metabolismo , Vitamina K 3/farmacocinética , Deficiência de Vitamina K/metabolismoRESUMO
Previous studies have shown that α-tocopherol intake lowers phylloquinone (PK) concentration in some extrahepatic tissues in rats. The study's aim was to clarify the effect of α-tocopherol intake on vitamin K concentration in bone, as well as the physiological action of vitamin K. Male Wistar rats were divided into 4 groups. Over a 3-mo period, the K-free group was fed a vitamin K-free diet with 50 mg RRR-α-tocopherol/kg, the E-free group was fed a diet containing 0.75 mg PK/kg without vitamin E, the control group was fed a diet containing 0.75 mg PK/kg with 50 mg RRR-α-tocopherol/kg, and the E-excess group was fed a diet containing 0.75 mg PK/kg with 500 mg RRR-α-tocopherol/kg. PK concentration in the liver was higher in E-excess rats than in E-free rats, was lower in the tibias of control rats than in those of E-free rats, and was lower in E-excess rats than in control rats. Menaquinone-4 (MK-4) concentration in the liver was higher in E-excess rats than in E-free and control rats. However, MK-4 concentrations in the tibias of E-free, control, and E-excess rats were almost the same. Blood coagulation activity was lower in K-free rats than in the other rats but was not affected by the level of α-tocopherol intake. Additionally, dietary intake of PK and α-tocopherol did not affect uncarboxylated-osteocalcin concentration in the serum, femur density, or expression of the genes related to bone resorption and formation in the femur. These results suggest that α-tocopherol intake decreases PK concentration in bone but does not affect bone metabolism in rats.
Assuntos
Desenvolvimento Ósseo , Osso e Ossos/metabolismo , Metabolismo Energético , Regulação da Expressão Gênica no Desenvolvimento , Vitamina K 1/antagonistas & inibidores , Deficiência de Vitamina K/etiologia , alfa-Tocoferol/intoxicação , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Densidade Óssea , Osso e Ossos/química , Dieta/efeitos adversos , Suplementos Nutricionais/intoxicação , Fígado/metabolismo , Masculino , Especificidade de Órgãos , Osteocalcina/sangue , Ratos Wistar , Organismos Livres de Patógenos Específicos , Tíbia , Vitamina K 1/metabolismo , Vitamina K 1/uso terapêutico , Vitamina K 2/análogos & derivados , Vitamina K 2/metabolismo , Deficiência de Vitamina K/metabolismo , Deficiência de Vitamina K/fisiopatologia , Deficiência de Vitamina K/terapia , Sangramento por Deficiência de Vitamina K/etiologia , Sangramento por Deficiência de Vitamina K/prevenção & controle , Aumento de PesoRESUMO
SCOPE: The effects of vitamin E on vitamin K metabolism were elucidated by comparing the effect of tocopherol intake on vitamin K concentrations in rats fed phylloquinone (PK) or menaquinone (MK)-4. METHODS AND RESULTS: Initially, the dietary effect of RRR-α-tocopherol, but not RRR-γ-tocopherol, in decreasing extrahepatic PK concentrations was confirmed. Subsequently, rats were fed a PK or MK-4-containing diet (0.75 mg/kg) with RRR-α-tocopherol (0, 10, 50, or 500 mg/kg) for 6 weeks. In rats fed PK, α-tocopherol consumption decreased PK in kidney, lung, heart, muscle, testis, and brain but not in serum and liver. However, in rats fed MK-4, α-tocopherol consumption did not decrease MK-4 in serum and tissues. Finally, vitamin K- and E-depleted rats were administered PK or MK-4 (0.2 mg) with RRR-α-tocopherol (0, 1, or 10 mg) by gavage. After PK administration, α-tocopherol was observed to decrease PK in kidney, adrenal gland, lung, testis, and brain but not in serum and liver, whereas, after MK-4 administration, α-tocopherol did not affect MK-4 in serum and tissues. CONCLUSION: Excess α-tocopherol decreased extrahepatic PK in rats fed PK but not MK-4 in rats fed MK-4.
Assuntos
Regulação para Baixo , Vitamina K 1/antagonistas & inibidores , Deficiência de Vitamina K/induzido quimicamente , alfa-Tocoferol/intoxicação , Animais , Suplementos Nutricionais , Masculino , Especificidade de Órgãos , Ratos Wistar , Organismos Livres de Patógenos Específicos , Deficiência de Vitamina E/sangue , Deficiência de Vitamina E/induzido quimicamente , Deficiência de Vitamina E/dietoterapia , Deficiência de Vitamina E/metabolismo , Vitamina K 1/administração & dosagem , Vitamina K 1/metabolismo , Vitamina K 1/uso terapêutico , Vitamina K 2/administração & dosagem , Vitamina K 2/análogos & derivados , Vitamina K 2/sangue , Vitamina K 2/metabolismo , Vitamina K 2/uso terapêutico , Deficiência de Vitamina K/sangue , Deficiência de Vitamina K/dietoterapia , Deficiência de Vitamina K/metabolismo , alfa-Tocoferol/administração & dosagem , alfa-Tocoferol/antagonistas & inibidores , alfa-Tocoferol/metabolismo , gama-Tocoferol/administração & dosagem , gama-Tocoferol/metabolismoRESUMO
From an enzyme kinetic study using rat liver microsomes, α-tocopherol has been suggested to accelerate the other vitamin E catabolism by stimulating vitamin E ω-hydroxylation, the late limiting reaction of the vitamin E catabolic pathway. To test the effect of α-tocopherol on catabolism of the other vitamin E isoforms in vivo, we determined whether α-tocopherol accelerates depletion of γ-tocopherol and tocotrienol and excretion of their metabolites in rats. Male Wistar rats were fed a γ-tocopherol-rich diet for 6 weeks followed by a γ-tocopherol-free diet with or without α-tocopherol for 7 days. Intake of γ-tocopherol-free diets lowered γ-tocopherol concentrations in serum, liver, adrenal gland, small intestine, and heart, but there was no effect of dietary α-tocopherol on γ-tocopherol concentrations. The level of urinary excretion of γ-tocopherol metabolite was not affected by dietary α-tocopherol. Next, the effect of α-tocopherol on tocotrienol depletion was examined using rats fed a tocotrienol-rich diet for 6 weeks. Subsequent intake of a tocotrienol-free diet with or without α-tocopherol for 7 days depleted concentrations of α- and γ-tocotrienol in serum and tissues, which was accompanied by a decrease in the excretion of γ-tocotrienol metabolite. However, neither the tocotrienol concentration nor γ-tocotrienol metabolite excretion was affected by dietary α-tocopherol. These data showed that dietary α-tocopherol did not accelerate the depletion of γ-tocopherol and tocotrienol and their metabolite excretions, suggesting that the positive effect of α-tocopherol on vitamin E ω-hydroxylase is not sufficient to affect the other isoform concentrations in tissues.