Search

Obesogenic diets are known to induce obesity and changes in food intake in experimental animals. Obesity negatively affects the peripheral metabolism and neural aspects, such as changes in eating behavior. In obese animals, dopamine (DA) receptor levels are reduced. DA is one of the main peptides involved in the motivation and pleasure of eating. A combination of naltrexone/bupropion (NB) has shown promise in controlling metabolic alterations, but there are few studies on how they modulate dopaminergic expression. NB, in addition to reducing food intake and body weight, can modify tyrosine hydroxylase (Th) and DA receptor D2 (Drd2) levels in the mesolimbic areas of rats submitted to a high-fat diet (HF). The study evaluated the effect of NB on food intake, body weight, and expression levels of Th, Drd1a, and Drd2, in the nucleus accumbens and striatum of rats fed on HF diet. Wistar rats were grouped according to diet: standard (n = 20) and HF diet (n = 20). The food intake and body weight were analyzed. The gene expression of Th, Drd1a, and Drd2 was evaluated using real-time PCR. NB combination of 1 mg/kg and 20 mg/kg reduced food intake and body weight, increased Drd2 expression in rats on HF diet, and increased Th in rats on both experimental diets. The level of Drd1a was unchanged. We concluded that bodyweight reduction may be associated with decreased food intake in response to the increased Drd2 expression in the mesolimbic areas of rats that received an HF diet.

Objetivo: o objetivo desse trabalho foi de identificar se o desmame precoce é capaz de ocasionar alterações morfológicas no tecido gástrico de ratos wistar. Método: Foram dividimos os filhotes de ratos em dois grupos, Grupo Desmame (n=6) e Grupo Controle (n=6). O Grupo Desmame foi desmamado no 15°dia de vida por separação materna, enquanto o Grupo Controle permaneceu com suas mães amamentando. Com 90 dias, os grupos foram submetidos a eutanásia e em seguida a retirada do estômago para o processamento histológico. As lâminas foram fotomicrografadas e analisadas. Resultado: Os dados mostraram que o desmame precoce aumenta a área da mucosa, aumentando assim a área das glândulas e da muscular da mucosa, com isso aumenta também a acidez estomacal. Também observamos que o desmame diminuiu a área da muscular longitudinal e submucosa, fazendo com que o organismo sofra adaptações para o funcionamento. Mostrando assim os riscos que o desmame precoce pode ocasionar a saúde.

The present study is a systematic review of the literature that aimed to characterize the profile in animal models used to study perinatal protein malnutrition correlating with the cardiovascular system and the implications of malnutrition to the heart. Therefore, an extensive search was conducted in the PubMed, BVS, and SciELO databases, using combinations of the descriptors protein malnutrition, pregnancy, heart, lactation, and cardiovascular system. A total of 247 articles were found, but after excluding duplicities and applying the inclusion/exclusion criteria, only 12 papers remained. The analysis of the results shows that the diet used in the studies has a protein content of between 17 and 22% for the control animals, and of between 0 and 9% for the animals submitted to perinatal protein malnutrition. The main morphofunctional changes observed in the cardiovascular system are related to high blood pressure, increased apoptosis of cardiomyocytes, and reduction in the absolute size of the heart, among other ultrastructural and molecular changes.

Fatty acid (FA) composition is a determinant of the physiological effects of dietary oils. This study investigated the effects of vegetable oil supplementation with different FA compositions on anthropometric and biochemical parameters in obese women on a hypocaloric diet with lifestyle modifications. Seventy-five women (body mass index, BMI, 30&ndash, 39.9kg/m2) were randomized based on 8-week oil supplementation into four experimental groups: the coconut oil group (CoG, n = 18), the safflower oil group (SafG, n = 19), the chia oil group (ChG, n = 19), and the soybean oil placebo group (PG, n = 19). Pre- and post-supplementation weight, anthropometric parameters, and body fat (%BF), and lean mass percentages (%LM) were evaluated, along with biochemical parameters related to lipid and glycidemic profiles. In the anthropometric evaluation, the CoG showed greater weight loss (&Delta, % = &minus, 8.54 &plusmn, 2.38), and reduced BMI (absolute variation, &Delta, abs = &minus, 2.86 &plusmn, 0.79), waist circumference (&Delta, 6.61 &plusmn, 0.85), waist-to-height ratio (&Delta, 0.041 &plusmn, 0.006), conicity index (&Delta, 0.03 &plusmn, 0.016), and %BF (&Delta, 2.78 &plusmn, 0.46), but increased %LM (&Delta, abs = 2.61 &plusmn, 1.40) (p &lt, 0.001). Moreover, the CoG showed a higher reduction in biochemical parameters of glycemia (&Delta, 24.71 &plusmn, 8.13) and glycated hemoglobin (&Delta, 0.86 &plusmn, 0.28) (p &lt, 0.001). The ChG showed a higher reduction in cholesterol (&Delta, 45.36 &plusmn, 0.94), low-density lipoprotein cholesterol (LDLc, &Delta, 42.53 &plusmn, 22.65), and triglycerides (&Delta, 49.74 &plusmn, 26.3), but an increase in high-density lipoprotein cholesterol (HDLc, abs = 3.73 &plusmn, 1.24, p = 0.007). Coconut oil had a more pronounced effect on abdominal adiposity and glycidic profile, whereas chia oil had a higher effect on improving the lipid profile. Indeed, supplementation with different fatty acid compositions resulted in specific responses.

Introdução. A obesidade pode ser considerada um dos principais pro­blemas de saúde pública mundial, com números alarmantes ao redor do mundo e correlação com diversas doenças de curso fatal. Fatores ambientais e vários sistemas fisiológicos estão implicados na causa da doença. Um destes sistemas, o de recompensa alimentar que envolve o neurotransmissor dopamina, é amplamente conhecido na literatu­ra como responsável pela motivação à busca de recompensas naturais (alimentos) e artificiais (drogas). Objetivo. Levantar dados na litera­tura que comprovem o envolvimento da dopamina com a hiperfagia e obesidade. Método. Foi realizada pesquisa em três bases de dados (MedLine, Lilacs e SciELO) com descritores e termos livres relacio­nados ao assunto, no período de maio/2013 a março/2014. Resul­tado. Foram encontrados 391 artigos. Após seleção criteriosa, com base nos critérios de exclusão definidos para este trabalho, apenas 17 artigos foram selecionados para discussão, os quais foram unânimes em apontar mudanças no sistema dopaminérgico em participantes obesos, como alterações na liberação de dopamina e na expressão de seus receptores. Conclusão. Futuros estudos precisam explorar mais esta condição através de desenhos experimentais adequados, seguindo o CONSORT, com grupos-controle e resultados validados interna­cionalmente, na expectativa de controlar os índices de morbi-mortali­dade decorrentes deste transtorno alimentar.

Feeding behavior is controlled by interactions between psychobiological and physiological systems. In rats, there is a sequence in the feeding behavior that is characterized by similar movements at the beginning and end of a meal, known as the behavioral satiety sequence. In the sequence, eating is followed by grooming and other activities, and ends with resting. The objective of this systematic review is to evaluate the use of the behavioral satiety sequence as an experimental model for the study of feeding behavior. A systematic search of the electronic databases MedLine, Lilacs, SciELO, Cochrane Library and PubMed was done from November 2007 to January 2008, using combinations of the keywords "behavioral," "satiety" and "sequence". Ninety articles were found and, of these, fifteen articles were selected for the review. The studies demonstrated the efficacy of using behavioral satiety sequence to evaluate the effects of some types of manipulations on feeding behavior. With this study method it was also possible to observe different factors that can interfere with feeding behavior, such as sedation, malaise or intake inhibition, by increasing satiety. Behavioral satiety sequence offers solid tools for gaining a better understanding of how treatment can influence feeding behavior.O comportamento alimentar é controlado por interações entre sistemas psicobiológicos e fisiológicos. Em ratos, existe uma sequência no comportamento alimentar que é caracterizada por movimentos similares no início e no término de uma refeição, conhecida como sequência comportamental de saciedade. Na sequência, o ato de comer é seguido pela limpeza e outra atividades, terminando com o descanso. O objetivo dessa revisão sistemática é avaliar o uso da sequência comportamental de saciedade como um modelo experimental para o estudo do comportamento alimentar. Uma busca sistemática das bases de dados MedLine, Lilacs, SciELO, Biblioteca Cochrane e PubMed foi realizada, no período de novembro de 2007 a janeiro de 2008, usando combinações das palavras chaves "behavioral", "satiety" e "sequence". Noventa artigos foram encontrados e, desses, quinze artigos foram selecionados para a revisão. Os estudos mostraram a eficácia do uso da sequência comportamental de saciedade para a avaliação dos efeitos de alguns tipos de manipulações sobre o comportamento alimentar. Com esse método de estudo, também é possível observar diversos fatores que podem intervir no comportamento alimentar, assim como sedação, mal-estar ou inibição do consumo por aumento da saciedade. A sequência comportamental de saciedade oferece sólidas ferramentas para obter um entendimento melhor de como um tratamento pode influenciar o comportamento alimentar.

Feeding behavior is controlled by interactions between psychobiological and physiological systems. In rats, there is a sequence in the feeding behavior that is characterized by similar movements at the beginning and end of a meal, known as the behavioral satiety sequence. In the sequence, eating is followed by grooming and other activities, and ends with resting. The objective of this systematic review is to evaluate the use of the behavioral satiety sequence as an experimental model for the study of feeding behavior. A systematic search of the electronic databases MedLine, Lilacs, SciELO, Cochrane Library and PubMed was done from November 2007 to January 2008, using combinations of the keywords "behavioral," "satiety" and "sequence". Ninety articles were found and, of these, fifteen articles were selected for the review. The studies demonstrated the efficacy of using behavioral satiety sequence to evaluate the effects of some types of manipulations on feeding behavior. With this study method it was also possible to observe different factors that can interfere with feeding behavior, such as sedation, malaise or intake inhibition, by increasing satiety. Behavioral satiety sequence offers solid tools for gaining a better understanding of how treatment can influence feeding behavior. O comportamento alimentar é controlado por interações entre sistemas psicobiológicos e fisiológicos. Em ratos, existe uma sequência no comportamento alimentar que é caracterizada por movimentos similares no início e no término de uma refeição, conhecida como sequência comportamental de saciedade. Na sequência, o ato de comer é seguido pela limpeza e outra atividades, terminando com o descanso. O objetivo dessa revisão sistemática é avaliar o uso da sequência comportamental de saciedade como um modelo experimental para o estudo do comportamento alimentar. Uma busca sistemática das bases de dados MedLine, Lilacs, SciELO, Biblioteca Cochrane e PubMed foi realizada, no período de novembro de 2007 a janeiro de 2008, usando combinações das palavras chaves "behavioral", "satiety" e "sequence". Noventa artigos foram encontrados e, desses, quinze artigos foram selecionados para a revisão. Os estudos mostraram a eficácia do uso da sequência comportamental de saciedade para a avaliação dos efeitos de alguns tipos de manipulações sobre o comportamento alimentar. Com esse método de estudo, também é possível observar diversos fatores que podem intervir no comportamento alimentar, assim como sedação, mal-estar ou inibição do consumo por aumento da saciedade. A sequência comportamental de saciedade oferece sólidas ferramentas para obter um entendimento melhor de como um tratamento pode influenciar o comportamento alimentar.

The objective of this work was to study the effect of early weaning on alimentary preference for the macronutrients protein, carbohydrate and fat in adult rats. Male Wistar rat pups were weaned by separation from the mother at 15 (D15) or 30 (D30) days old. Body weight and food intake were measured every 30 days until pups were 150 days old. At 110 days of age, the alimentary preference was evaluated for 1 h on 3 consecutive days. At 120 days of age, the palatable diet test was conducted during 3 consecutive 24-h periods. Body weight and food intake were not altered, but early weaning in rats induced an alimentary preference to fat and hyperphagia of a palatable diet. In conclusion, early weaning, although did not modify body weight or basal food intake, promoted an increased preference for palatable and fatty foods. This demonstrates that early weaning is not capable of promoting perceptible alterations of alimentary behavior under normal laboratory conditions. However, in the presence of a stimulating factor such as a choice of nutrients or a palatable diet, a possible latent effect on dietary preferences may become apparent. Over the long term, this preference for foods with high caloric density can lead to obesity and metabolic perturbations.

Protein malnutrition during the perinatal period leads to several morphological and physiological changes in the central nervous system whose main purpose is to prepare the body for environmental conditions. Several studies have been developed to explain the effects that malnutrition causes over feeding behavior in adults, and in particular on the role of the serotonergic system in this control. Thus, the objective of this systematic review was to assess emerging literature on the effects of perinatal malnutrition on the control of feeding behavior and the role of the serotonergic system in this control. The articles were researched in the virtual libraries Pubmed, Lilacs and Medline using as keywords: "Protein Malnutrition", "Feeding Behavior", "Serotonin Receptors", "Gestational malnutrition", "Perinatal undernutrition", "Fetal Nutrition Disorders" and "Serotonin". 261 articles in total were found. However, after excluding duplicates and analysis of the criteria for inclusion and exclusion 8 articles remained. Analysis of the articles showed that malnutrition in the perinatal period leads to changes in food preference in rats, in addition to delaying the point of satiety of these animals. It was also found that there is increased protein expression of c-fos groups forebrain neurons, increased expression of 5HT-1A receptors and increase in brain serotonin levels. These findings suggest that changes in eating behavior in malnourished animals can be brought about due to changes in the serotonergic system.

The objective of this work was to study the effect of early weaning on circadian rhythm and the behavioral satiety sequence in adult rats. Male Wistar rat pups were weaned for separation from the mother at 15 (D15), 21 (D21) and 30 (D30) days old. Body weight and food intake was measured every 30 days until pups were 150 days old. At 90 days of age, the circadian rhythm of food intake was evaluated every 4h for three days. Behavioral satiety was evaluated at 35 and 100 days of age. This work demonstrated that body weight and food intake were not altered, but the behavioral satiety sequence demonstrated that the D15 group delayed satiety compared with the D30 group at 100 days of age. In the circadian rhythm of the food intake study, early weaning (D15) changed food intake in the intermediary period of the light phase and in the intermediary period of the dark phase. In conclusion, our study showed that early weaning may alter the feeding behavior mainly in relation to satiety and the circadian rhythm of feeding. It is possible that the presence of other environmental stimuli during early weaning can cause hyperphagia and deregulate the mechanisms of homeostasis and body weight control. This study supports theories that depict insults during early life as determinants of chronic diseases.