Fasting levels of appetite regulating hormones predict caloric intake at breakfast in a group of Chilean adolescents / Los niveles en ayunas de hormonas reguladoras del apetito predicen la ingesta energética en el desayuno en adolescentes

BACKGROUND: Appetite regulation is integral to food intake and is modulated by complex interactions between internal and external stimuli. Hormonal mechanisms which stimulate or inhibit intake have been characterized, but the physiologic effects of serum levels of such hormones in short-term appetite regulation have received little attention. AIM: To evaluate whether fasting levels of orexigenic/anorexigenic hormones were associated with energy intake at breakfast, served soon after drawing a fasting blood sample, in a group of adolescents. MATERIAL AND METHODS: Anthropometry, body composition and fasting blood levels of leptin, insulin, ghrelin, and orexin-A were measured in 655 Chilean adolescents aged 16.8 ± 0.3 years (52% males). Energy intake was measured at a semi-standardized breakfast. Associations between hormone levels and energy intake were studied using multivariate linear models. RESULTS: Thirty nine percent of participants were overweight/ obese. After an overnight fast, median values for leptin, insulin, ghrelin and orexin-A were 7.3 ng/mL, 6.7 IU/dL, 200.8 pg/mL, and 16.1 pg/mL, respectively. Participants ate on average 637 ± 239 calories at breakfast. In multivariable models, insulin levels were inversely and independently associated with caloric intake at breakfast (β = −18.65; p < 0.05), whereas leptin, ghrelin and orexin-A levels were positively and independently associated with intake: β= 5.56, β = 0.34 and β = 8.40, respectively, p < 0.05. CONCLUSIONS: Fasting leptin, ghrelin and orexin-A were positively associated with energy intake during breakfast provided soon after the blood draw. Insulin was negatively associated with energy intake. Modifiable factors influencing levels of appetite regulating hormones could be a potential target for influencing food intake.

ANTECEDENTES: La regulación del apetito es parte integral de la ingesta alimentaria y es modulada por complejas interacciones entre estímulos internos y externos. Se han caracterizado los mecanismos hormonales que estimulan o inhiben la ingesta, pero los efectos fisiológicos de los niveles séricos de tales hormonas en la regulación del apetito a corto plazo han recibido poca atención. OBJETIVO: Evaluar si los niveles en ayunas de hormonas orexigénicas/ anorexigénicas se asocian con la ingesta energética en el desayuno, entregado inmediatamente después de una muestra de sangre en ayunas, en un grupo de adolescentes. MATERIAL Y MÉTODO: Se efectuaron mediciones antropométricas, composición corporal y medición de niveles en ayunas de leptina, insulina, grelina y orexina-A en 655 adolescentes de 16,8 ± 0,26 años. La ingesta energética se midió en un desayuno semiestandarizado. Se estudiaron las asociaciones entre los niveles hormonales y la ingesta energética mediante modelos lineales multivariados. RESULTADOS: Los valores de leptina, insulina, grelina y orexina-A fueron 7,3 ng/mL, 6,7 UI/dL, 200,8 pg/mL y 16,1 pg/mL respectivamente. Los participantes comieron un promedio de 637 ± 239 calorías en el desayuno. Los niveles de insulina se asociaron inversa e independientemente con la ingesta del desayuno (β = −18,65; p < 0,05), mientras que los niveles de leptina, grelina y orexina-A se asociaron positiva e independientemente con la ingesta: β = 5,65; β = 0,34; β = 8,40, (p < 0,05). CONCLUSIONES: La leptina, grelina y orexina-A en ayunas se asociaron positivamente con la ingesta de energía durante el desayuno proporcionado poco después de la muestra de sangre. La insulina se asoció negativamente con la ingesta de energía. Los factores modificables que influyen en las hormonas reguladoras del apetito podrían ser un objetivo potencial para influir en la ingesta de alimentos.

Deseo intenso por alimentos apetecibles: validación y estandarización del Food Craving Questionnaire-Trait en México / Intense craving for appetizing foods: validation and standardization of the Food Cravings Questionnaire-Trait in Mexico

Resumen Introducción: El food craving o “ansia por comer” es una respuesta motivacional y fisiológica por comer alimentos específicos, principalmente con alto contenido calórico. Para evaluarlo se usa, entre otros, el Food Craving Questionnaire Trait, estructurado multidimensionalmente y validado en diversos países, el cual ha mostrado ser sensible y adaptable a los cambios contextuales-culturales. Objetivos: Validar y estandarizar el Food Craving Questionnaire-Trait en adultos de la Ciudad de México. Método: Estudio no experimental, transversal y aleatorizado de 1059 sujetos de uno y otro sexo, entre 18 y 84 años; 71.86 % del sexo femenino. Se examinaron propiedades psicométricas con análisis factoriales exploratorios y confirmatorios. Resultados: Se redujeron los factores del cuestionario y los ítems se reorganizaron de forma diferente al original. El análisis factorial confirmatorio mostró ajuste adecuado y estandarización aceptable de los factores. Se encontró alta consistencia interna para el cuestionario global (a = 0.973 y rho = 0.975) para cada uno de los factores. Conclusión: Este estudio determina la viabilidad del Food Craving Questionnaire para población de la Ciudad de México.

Abstract Introduction: Food craving is a motivational and physiological response for eating specific foods, mainly with high caloric content. To assess food craving, self-reports, inventories and questionnaires are used. The Food Cravings Questionnaire-Trait is multi-dimensionally structured and has been validated in several countries, since it is sensitive and adaptable to contextual-cultural changes. Objectives: To validate and standardize the Food Cravings Questionnaire-Trait in adults of Mexico City. Method: Non-experimental, cross-sectional, randomized study of 1059 subjects of both genders, between 18 and 84 years of age; 71.86 % of the female gender. Psychometric properties were examined with exploratory and confirmatory factor analyses. Results: The domains of the questionnaire were reduced and the items were reorganized differently from the original version. The confirmatory factor analysis showed an adequate fit and acceptable standardization of factors. High internal consistency was found for the global questionnaire (a = 0.973 and rho = 0.975) for each one of the domains. Conclusion: This study determines the viability of the Food Cravings Questionnaire for the population of Mexico City.

Appetite Assessment of Hospitalized Cancer Patients in Brazil - A Validation Study

OBJECTIVES: Appetite loss, a common symptom in cancer patients, contributes to worsened nutritional status. A validated specific tool to assess appetite is clinically useful for diagnosing and identifying symptoms and signs that could be reversed with nutritional and pharmacological therapies. The aim of this study is to produce a Brazilian Portuguese version of the Hill and Blundell visual analog scale (VAS) for appetite and investigate its validity among hospitalized cancer patients. METHODS: The original English VAS version was translated into Brazilian Portuguese in full accordance with the guidelines in the literature and adapted to the Brazilian context by conducting interviews and meetings with an expert committee until the final version was reached. Afterwards, the version was validated in hospitalized cancer patients in a cross-sectional study at São Paulo Cancer Institute (ICESP), where the relationships between breakfast intake (rest-ingestion index) and VAS were compared. The Spearman test was used to verify the correlation between the rest-ingestion index and the VAS ratings. RESULTS: Sixty-four patients with a mean age of 56.1 (±12.3) years answered the Portuguese VAS version, and their breakfast intake was evaluated. The mean rest-ingestion index was 18.8%. The correlations between the rest-ingestion index (food acceptance) and three questions of the Portuguese visual analog scale version were inverse and significant: first question (ρ -0.3028 p=0.0046), second question (ρ -0.2317 p=0.0319) and third question (ρ -0.3049 p=0.0043). CONCLUSION: The "Appetite Assessment Scale of Brazilian Oncology Patients" is a valid instrument to assess appetite in hospitalized cancer patients in Brazil.

Influencia en el balance energético de los factores que regulan el control del apetito y la saciedad a corto plazo / Influence of the regulating factors of short-term control of appetite and satiety on energy balance

Introducción: el mantenimiento de un nivel constante de energía almacenada es gracias a los factores que regulan el apetito y la saciedad, los cuales influyen en el estado del balance energético. Objetivo: describir la influencia en el balance energético de los factores que regulan el control del apetito y la saciedad a corto plazo. Métodos: se realizó una búsqueda en Medline/PubMed, Bireme, ediciones DOYMA y Elsevier, de artículos publicados en inglés y español en el período comprendido entre enero de 1973 y junio de 2016. Los términos de búsqueda fueron food intake, energy balance, regulation, nutritional homeostasis. Desarrollo: la ingesta de alimentos es una conducta humana que resulta de la compleja interacción entre múltiples factores, en que los más importantes son los fisiológicos y, en el plano humoral, está bien establecido el papel de la ghrelina en la iniciación de la ingesta. Al unísono se ponen en marcha diferentes órganos desde este mismo momento para establecer el momento en el que se debe dejar de comer, mecanismo en el cual intervienen hormonas como colecistoquinina, péptido similar al glucagón tipo 1, oxintomodulina, péptido YY, bombesina, enterostatina, amilina y polipéptido pancreático. Consideraciones finales: existen diferentes mecanismos implicados en la regulación del control a corto plazo del apetito y la saciedad, los cuales se encuentran íntimamente relacionados, e influyen y determinan el estado del balance energético(AU)

Introduction: steady level of stored energy is kept thanks to regulating factors of appetite and satiety which also influence on the state of energy balance. Objective: to describe the influence of regulating factors of appetite and satiety at short-term on the energy balance. Methods: a literature search was made in Medline/PubMed, Bireme, DOYMA editions and Elsevier to find English and Spanish articles in the period of January 1973 to June 2016. The search terms were food intake, energy balance, regulation, nutritional homeostasis. Development: food intake is human behavior resulting from the complex interaction of multiple factors, being the most important the physiological ones and at the humoral level, the role of ghrelina in the onset of intake is well-established. At the same time, various organs set in motion to fix the moment when one should stop eating, a mechanism in which several hormones are involved such as cholecystokinin, a peptide similar to type 1 glycagon, oxyntomodulin, peptide YY, bombesin, enterostatin, amyline and pancreatic polypeptide. Final thoughts: there are several mechanisms involved in the regulation of the short-term control of appetite and satiety which are closely related, have an effect on and determine the state of the energy balance(AU)

Participação dos receptores delta e kappa-opioides centrais no controle do apetite por sódio em ratos estimulados a ingerir solução salina hepertônica / Participation of delta receptors and central kappa-opioids in control of the sodium appetite in rats stimulated to saline ingerirsolução hepertônica

Alguns estudos sugerem que as vias opioidérgicas centrais parecem desempenhar um papel regulatório no controle da ingestão de água e sal em mamíferos. As ações dos opioides centrais sobre a regulação do controle hidroeletrolítico são mediadas por vários dos subtipos de receptores opioides. O papel dos receptores delta e kappa-opioides centrais neste processo não está adequadamente elucidado sendo necessário mais estudos que o esclareçam. Objetivo: Este estudo investigou o envolvimento dos receptores delta e kappa-opioides centrais no apetite por sódio em ratos depletados deste íon e em rato ativados centralmente com angiotensina. Material e Métodos: Foram utilizados ratos Wistar (270 ± 20 g), submetidos à cirurgia estereotáxica para implante de cânula guia no ventrículo lateral esquerdo (VL), no órgão subfornical (OSF), no núcleo preóptico mediano (MnPO) e no núcleo basolateral da amígdala (BLA). No protocolo de depleção de sódio os animais foram submetidos à injeção subcutânea de furosemida combinada com dieta hipossódica quatro dias após a cirurgia. Neste modelo de estudo os animais receberam injeção intracerebroventricular (i.c.v.) do antagonista delta-opioide naltrindole no quinto dia pós-cirúrgico, nas doses de 5, 10 e 20 nmol/2 μL e do antagonista kappa-opioide, norbinaltorfimina, injetado no OSF, MnPO e BLA, nas doses de 0,5, 1,0 e 2,0 nmol/0,2 μL...

Central opioid pathways seem to have an important role on the control of water and salt intake in mammals, and brain opioid peptides may influence hydroelectrolyte balance through a myriad of actions mediated by distinct opioid receptors. The specific role of central delta and kappa-opioid receptors (DOR and KOR) in this process is far from being fully understood. In the present work, we investigated the role of those receptors in the control of water and salt intake, in sodium-depleted rats and rats with activation central angiotensinergic. Method: Wistar male rats (250 ± 20 g) were used in the experiment after stereotaxic cannulation of the VL left, SFO, MnPO and BLA. To study the effect of the blockade of central DOR and KOR on water and salt intake in rats were sodium depleted by the concomitant use of s.c. injections of furosemide and were kept in hypossodic diet, five days after surgery. In the sixth day, they received i.c.v. injections of a selective delta-opioid receptor antagonist (naltrindole) at the doses of 5, 10 and 20 nmol/2 μL and injections in the SFO, MnPO and BLA of a selective kappa-opioid receptor antagonist (norbinaltorphimine) at the doses of 0.5, 1.0 and 2.0 nmol/0.2 μL...

Factores dietéticos y su relación con el apetito en niños menores de dos años con desnutrición leve

La desnutrición está condicionada por una serie de factores, entre ellos los dietéticos que comprenden apetito, conductas y hábitos alimentarios, lo que planteó el siguiente objetivo: describir los factores dietéticos y su relación con el apetito en niños menores de dos años con desnutrición leve. El estudio fue correlacional, la muestra quedo constituida por todos los niños menores de dos años (n=168) con diagnóstico de desnutrición leve primaria que asistieron a la consulta del Centro de Atención Nutricional Infantil Antímano, CANIA, durante el período 2000-2008. Los resultados señalaron: consumo de energía y macronutrientes inferior al requerimiento individual, consumo de hierro <85% del requerimiento según Recommended Dietary Allowances (RDA) en más del 50% de la niños; la frecuencia de consumo semanal para vegetales (57%) y misceláneos (66%) fue inadecuada; más del 60% tuvo un consumo inadecuado de fórmulas lácteas y leche completa, 9% recibió lactancia materna exclusiva durante los 6 primeros meses de vida; 64% no tuvo lugar fijo para alimentarse; en la interacción del niño con el cuidador durante las comidas más de la mitad de los niños se mostraron rebeldes y los cuidadores permisivos. La adecuación de proteínas, frecuencia de consumo de vegetales y leche completa, tipo de preparación, identificación de rechazos y preferencias, lugar y duración de las comidas, interacción del niño y del cuidador durante la alimentación tuvieron asociación significativa con el apetito; si se considera este ultimo como una guía y se actúa para modificar los hábitos y conductas inadecuadas se generaría un impacto sobre el apetito del niño que pudiera mejorar su ingesta de alimentos y prevenir la desnutrición.

Dietary factors and their relation to appetite in children under two years with mild malnutrition. Malnutrition is conditioned by a series of factors, among them the dietary factors, which include appetite, eating behaviors and habits. In order to assess these factors, the following objective was pursued: describe the dietary factors and their relation to appetite in children under two years of age with mild malnutrition. A correlational study was conducted. The sample consisted of all children under two years of age (n=168) diagnosed with primary (mild) malnutrition, who attended consultation at the Centro de Atención Nutricional Infantil Antímano, CANIA, during the period 2000 - 2008. The results showed: intake of energy and macronutrients was lower than the individual requirement; iron intake <85% of the requirement, in accordance with the Recommended Dietary Allowances (RDA) in over 50% of the sample; weekly consumption of vegetables (57%) and miscellaneous (66%) was inadequate; inadequate intake of formula and whole milk in more than 60%; 9% were exclusively breastfed during the first six months; 64% lacked a regular eating place; in child-caregiver interaction during mealtimes, more than half of the children showed rebellious behavior and caregivers were permissive. Protein adequacy, vegetable and whole milk consumption frequency, preparation type, identification of refusals and preferences, place and duration of meals, and child-caregiver interaction at mealtimes were significantly associated with appetite; if we consider this last one as a guide and we try to modify inadequate eating behaviors and habits, we will generate an impact over the child appetite that could improve the food consumption and prevent malnutrition.

La reducción del sueño como factor de riesgo para obesidad / Sleep deprivation as a risk factor for obesity

Nocturnal sleep patterns may be a contributing factor for the epidemic of obesity. Epidemiologic ana experimental studies have reported that sleep restriction is an independent risk factor for weight gain and obesity. Moreover, sleep restriction is significantly associated with incidence and prevalence of obesity and several non-transmissible chronic diseases. Experimental sleep restriction is related to altered plasma leptin and ghrelin concentrations. Both hormones are directly related to appetite and satiety mechanisms. Also, a higher activity of the orexin/hypocretin system has been reported, as well as changes in glucose metabolism and autonomic nervous system. Some studies indicate that these endocrine changes could be associated with a higher diurnal food intake and preference for energy- dense foods. All these changes could result in a positive energy balance, leading to weight gain and a higher obesity risk in the long-term. The present article summarizes the epidemiologic and experimental evidence related to sleep deprivation and higher obesity risk. The possible mechanisms are highlighted.

Changes in sodium appetite evoked by lesions of the commissural nucleus of the tractus solitarius

Ablation of the area postrema/caudal nucleus of the tractus solitarius (NTS) complex increases sodium intake, but the effect of selective lesions of the caudal NTS is not known. We measured depletion-induced sodium intake in rats with electrolytic lesions of the commissural NTS that spared the area postrema. One day after the lesion, rats were depleted of sodium with furosemide (10 mg/kg body weight, sc) and then had access to water and a sodium-deficient diet for 24 h when 1.8 percent NaCl was offered. Water and saline intakes were measured for 2 h. Saline intake was higher in lesioned than in sham-lesioned rats (mean ± SEM: 20 ± 2 vs 11 ± 3 mL/2 h, P < 0.05, N = 6-7). Saline intake remained elevated in lesioned rats when the tests were repeated 6 and 14 days after the lesion, and water intake in these two tests was increased as well. Water intake seemed to be secondary to saline intake both in lesioned and in sham-lesioned rats. A second group of rats was offered 10 percent sucrose for 2 h/day before and 2, 7, and 15 days after lesion. Sucrose intake in lesioned rats was higher than in sham-lesioned rats only 7 days after lesioning. A possible explanation for the increased saline intake in rats with commissural NTS lesions could be a reduced gastrointestinal feedback inhibition. The commissural NTS is probably part of a pathway for inhibitory control of sodium intake that also involves the area postrema and the parabrachial nucleus.

Role of the serotoninergic system in the sodium appetite control

The present article reviews the role of the serotoninergic system in the regulation of the sodium appetite. Data from the peripheral and icv administration of serotoninergic (5-HTergic) agents showed the participation of 5-HT2/3 receptors in the modulation of sodium appetite. These observations were extended with the studies carried out after brain serotonin depletion, lesions of DRN and during blockade of 5-HT2A/2C receptors in lateral parabrachial nucleus (LPBN). Brain serotonin depletion and lesions of DRN increased the sodium appetite response, in basal conditions, after sodium depletion and hypovolemia or after beta-adrenergic stimulation as well. These observations raised the hypothesis that the suppression of ascending pathways from the DRN, possibly, 5-HTergic fibers, modifies the angiotensinergic or sodium sensing mechanisms of the subfornical organ involved in the control of the sodium appetite. 5-HTergic blockade in LPBN induced to similar results, particularly those regarded to the natriorexigenic response evoked by volume depletion or increase of the hypertonic saline ingestion induced by brain angiotensinergic stimulation. In conclusion, many evidences lead to acceptation of an integrated participation resulting of an interaction, between DRN and LPBN, for the sodium appetite control.

Este artigo revisa o papel do sistema serotoninérgico no controle do apetite ao sódio. Dados derivados da administração periférica e icv de agentes serotoninérgicos demonstraram a participação de receptores 5-HT2/3 na modulação do apetite ao sódio. Estas observações foram estendidas com os estudos realizados após a depleção cerebral de serotonina, lesões do NDR e durante o bloqueio 5-HT2A/2C no núcleo parabraquial lateral (NPBL). A depleção cerebral de serotonina e as lesões do NDR aumentaram o apetite ao sódio, em condições basais, após depleção de sódio, durante a hipovolemia ou após a estimulação beta-adrenérgica. Estas evidências suscitaram a hipótese de que a supressão de vias ascendentes do NDR, possivelmente 5-HT, alteram os mecanismos angiotensinérgicos e a atividade dos sensores de sódio do órgão subfornicial envolvidos no controle do apetite ao sódio. O bloqueio serotoninérgico no NPBL induziu a resultados similares, particularmente aqueles relacionados com a resposta natriorexigênica provocada pela depleção de volume ou o aumento da ingestão de salina hipertônica induzida pela estimulação angiotensinérgica cerebral. Em resumo, as evidências convergem para a admissão de uma participação integrada resultante da interação recíproca entre NDR e NPBL objetivando controlar o apetite ao sódio.

Water deprivation and the double- depletion hypothesis: common neural mechanisms underlie thirst and salt appetite

Water deprivation-induced thirst is explained by the double-depletion hypothesis, which predicts that dehydration of the two major body fluid compartments, the extracellular and intracellular compartments, activates signals that combine centrally to induce water intake. However, sodium appetite is also elicited by water deprivation. In this brief review, we stress the importance of the water-depletion and partial extracellular fluid-repletion protocol which permits the distinction between sodium appetite and thirst. Consistent enhancement or a de novo production of sodium intake induced by deactivation of inhibitory nuclei (e.g., lateral parabrachial nucleus) or hormones (oxytocin, atrial natriuretic peptide), in water-deprived, extracellular-dehydrated or, contrary to tradition, intracellular-dehydrated rats, suggests that sodium appetite and thirst share more mechanisms than previously thought. Water deprivation has physiological and health effects in humans that might be related to the salt craving shown by our species.

Matching salt intake to physiological need in rats using foraging protocols

Several studies of the quantitative relationship between sodium need and sodium intake in rats are reviewed. Using acute diuretic treatment 24 h beforehand, intake matches need fairly accurately when intake is spread out in time by using a hypotonic solution of NaCl. In contrast, using a hypertonic solution, intake is typically double the need. Using the same diuretic treatment, although the natriuresis occurs within ~1 h, the appetite appears only slowly over 24 h. Increased plasma levels of aldosterone parallel the increased intake; however, treatment with metyrapone blocks the rise in aldosterone but has no effect on appetite. Satiation of sodium appetite was studied in rats using sodium loss induced by chronic diuretic treatment and daily salt consumption sessions. When a simulated foraging cost was imposed on NaCl access in the form of a progressive ratio lever press task, rats showed satiation for NaCl (break point) after consuming an amount close to their estimated deficit. The chronic diuretic regimen produced hypovolemia and large increases in plasma aldosterone concentration and renin activity. These parameters were reversed to or toward non-depleted control values at the time of behavioral satiation in the progressive ratio protocol. Satiation mechanisms for sodium appetite thus do appear to exist. However, they do not operate quantitatively when concentrated salt is available at no effort, but instead allow overconsumption. There are reasons to believe that such a bias toward overconsumption may have been beneficial over evolutionary time, but such biasing for salt and other commodities is maladaptive in a resource-rich environment.

Efeitos do índice glicêmico no balanço energético / Effects of glycemic index on energy balance

A prevalência da obesidade vem crescendo nas últimas décadas. Associado a este fato, tem-se observado uma mudança no padrão dietético da população em geral, no que diz respeito a um maior consumo de carboidratos. Segundo alguns autores, o índice glicêmico (IG) dos alimentos afeta a composição e o peso corporal. A presente revisão de literatura teve como objetivo avaliar os efeitos do IG sobre apetite, saciedade e composição corporal. A partir das evidências científicas analisadas, foi possível constatar que a maioria dos estudos que atribuem efeitos positivos ao IG é cercada de limitações metodológicas. Estudos bem delineados não observaram benefícios do IG sobre os parâmetros citados acima. Diante disso, conclui-se que o IG apresenta pouca aplicabilidade na prática clínica, como uma ferramenta capaz de controlar a saciedade, reduzir o apetite e, conseqüentemente, a prevalência de obesidade.

The prevalence of obesity has increased over the last decades. Associated to this, there has been observed a chance in the dietetic pattern of the population in general, related to the increase in carbohydrate consumption. According to some authors, the glycemic index (GI) of food may affect body composition and body weight. The purpose of this review was to evaluate the effects of GI on appetite, satiety, and body composition. Based on the scientific evidences reviewed, it was possible to verify that the majority of the studies that observed a positive effect of GI in that matter have a lot of methodological limitations. Well-designed studies have not observed any benefit of GI on these parameters. Therefore, it is concluded that GI has little application in clinical practice, as a useful tool to control satiety, reduce appetite, and consequently, to reduce the prevalence of obesity.

Estudo da participação dos receptores histaminérgicos centrais dos tipos H1 e H2 no controle da ingestão de água / Study of participation of central histaminergic types H1 and H2 in the control of water intake

Diferentes grupos de pesquisa têm se dedicado à investigação dos mecanismos cerebrais de controle da sede. O avanço neste campo da Neurociência tem trazido importantes contribuições para a compreensão da regulação da homeostasia hidrossalina, o que pode levar a futuras aplicações clínicas. Desde a década de 1950 tem sido sugerido que a histamina pode atuar como neuromodulador/neurotransmissor no sistema nervoso central, entretanto sua função ainda não é clara, especialmente no que concerne ao controle da homeostasia hidrossalina. Assim o objetivo do presente trabalho foi investigar o papel das vias histaminérgicas centrais no controle da ingestão hídrica e ingestão de água pós-prandial. Foram utilizados quatro modelos de estudo: ingestão hídrica em animais normoidratados, em animais desidratados por privação hídrica e por sobrecarga de sódio e pós-prandial. No primeiro grupo ratos normoidratados receberam microinjeções bilaterais no núcleo ventromedial hipotalâmico (VMH), de HTMT, agonista específico para os receptores histaminérgicos do tipo H1, nas doses de 100 e 200 nmol e dimaprite agonista para os receptores H2 na dose de 100 nmol. No segundo grupo, animais em privação hídrica por 14 horas "overnight" foram injetados no VMH com mepiramine, antagonista dos receptores histaminérgicos H1, e cimetidine, antagonista específico para os receptores H2 nas doses de 100 e 200 nmol. No terceiro grupo foi realizado em animais sob desidratação osmótica induzida por sobrecarga da salina hipertônica (solução salina 9% num volume de 10% do peso corporal). Nesses três grupos o volume ingerido pelos animais foi monitorado a cada 15 minutos durante 2 horas. No quarto grupo as 18:00 horas foram aplicadas microinjeçóes de mepiramine e cimetidine na dose de 200 nmol para a investigação da ingestão hídrica pós-prandial. A ingestão alimentar e o volume hídrico ingeridos deste grupo foram monitorados a cada 30 minutos durante as primeiras 4 horas do período noturno e ao fim deste período (6:00 h)...

Síndrome X vs síndrome metabólico: entendiendo sus coincidencias y sus diferencias hacia una [quot ]nueva cardiología[quot ] / Syndrome X vs metabolic syndrome

Himsworth in 1939 postulated that Diabetes Mellitus type 2 (DM2) was not only an insulin deficiency state but also a cellular insulin insensitivity disease. Thirty years later, DeFronzo and Reaven demonstrated that insulin resistance (IR) preceded and predisposed for DM2 and atherosclerotic-cardiovascular-disease (ACVD). Reaven was the first to point out the relationship between IR and with hyperglycemia, dyslipidosis, and hypertension as mediators for ACVD, creating the concept of Syndrome X (SX) in 1988. WHO and, thereafter, other medical societies and medical groups, mainly ATP-III, in 2002, based on the difficulty of diagnosing IR in a simple, reliable, and inexpensive way, proposed and published the Metabolic Syndrome (MS) concept, as a group of five variables, i.e., obesity, hyperglycemia, hypertriglyceridemia, low HDL, and hypertension, as an easy clinical approximation to suspect and treat an increased cardiometabolic risk. Nowadays, there are deep and extensive controversies on this issue; however, these controversies do not really exist since all discordant points of view are rather quantitative and not qualitative in nature. This article is aimed at differentiating and harmonizing the complementary concepts of SX and MS, at analyzing why MS is a good [quot ]clinical window[quot ] to look for IR and its underlying manifestations, and finally to accept that the MS concept complements, but does not substitute or antagonize, traditional scales used to asses cardiovascular risk, such as the Framingham scale.

Ghrelin - A Novel Appetite-stimulating Hormone Which Also Affects Gastrointestinal Functions / 대한소화기학회지

Ghrelin, a novel gastrointestinal peptide with 28 amino acids, is secreted from the A-like cells of the gastric fundus. This peptide hormone does not only promote the release of growth hormone, but also stimulates food intake, gastric motility and cardiac output. Increased plasma ghrelin level has been reported in patients with upper gastrointestinal (GI) disease or in their disease animal model, suggesting its important role in the pathogenesis of upper GI disease.

Chronic excitotoxic lesion of the dorsal raphe nucleus induces sodium appetite

We determined if the dorsal raphe nucleus (DRN) exerts tonic control of basal and stimulated sodium and water intake. Male Wistar rats weighing 300-350 g were microinjected with phosphate buffer (PB-DRN, N = 11) or 1 æg/0.2 æl, in a single dose, ibotenic acid (IBO-DRN, N = 9 to 10) through a guide cannula into the DRN and were observed for 21 days in order to measure basal sodium appetite and water intake and in the following situations: furosemide-induced sodium depletion (20 mg/kg, sc, 24 h before the experiment) and a low dose of dietary captopril (1 mg/g chow). From the 6th day after ibotenic acid injection IBO-DRN rats showed an increase in sodium appetite (12.0 ± 2.3 to 22.3 ± 4.6 ml 0.3 M NaCl intake) whereas PB-DRN did not exceed 2 ml (P < 0.001). Water intake was comparable in both groups. In addition to a higher dipsogenic response, sodium-depleted IBO-DRN animals displayed an increase of 0.3 M NaCl intake compared to PB-DRN (37.4 ± 3.8 vs 21.6 ± 3.9 ml 300 min after fluid offer, P < 0.001). Captopril added to chow caused an increase of 0.3 M NaCl intake during the first 2 days (IBO-DRN, 33.8 ± 4.3 and 32.5 ± 3.4 ml on day 1 and day 2, respectively, vs 20.2 ± 2.8 ml on day 0, P < 0.001). These data support the view that DRN, probably via ascending serotonergic system, tonically modulates sodium appetite under basal and sodium depletion conditions and/or after an increase in peripheral or brain angiotensin II.

Determinantes fisiológicos do controle do peso e apetite / Physiological determinants of weight and appetite control

A obesidade é um dos principais problemas de saúde pública da atualidade, apresentando etiologia multifatorial. Entre os determinantes fisiológicos do controle do peso e do apetite, estão fatores neuronais, endócrinos, adipocitários e intestinais. A leptina e a insulina são hormônios secretados em proporção à massa adiposa e atuam perifericamente, estimulando o catabolismo. No sistema nervoso central, a insulina e a leptina interagem com receptores hipotalâmicos, favorecendo a saciedade. Indivíduos obesos têm maiores concentraçäes séricas destes hormônios e apresentam resistência à sua ação. Os peptídeos intestinais, combinados a outros sinais, podem estimular (grelina e orexina) ou inibir (CCK, leptina e oximodulina) a ingestão alimentar. Todos atuam nos centros hipotalâmicos, que são os grandes responsáveis pelo comportamento alimentar.

Representaçöes gustativas no córtex humano, e o controle central do apetite / Taste representation in the human cortex and the central control of appetite

Tem sido estabelecido que o controle da ingestäo de nutrientes e o decorrente estado de equilíbrio homeostático dependem de uma série de sinais periféricos que atuam diretamente sobre o sistema nervoso central, levando a respostas adaptativas apropriadas. Entretanto, em humanos, a crescente incidência de patologias produzidas em grande medida por distúrbios da preferência alimentar, tais como obesidade e anorexia, implica no envolvimento do córtex no controle da ingestäo de alimentos. Estudos recentes fazendo uso da neuroimagem funcional em voluntários humanos revelam que o processamento central da informaçäo gustativa é implementado em humanos em áreas análogas a de outros primatas. As áreas corticais gustativas primárias, localizadas no complexo ínsulo-opercular, respondem eficientemente durante a decodificaçäo de estímulos externos através do isolamento dos sinais que codificam o estado fisiológico do organismo. As áreas específicas do córtex pré-frontal em sua parte ventro-média parecem, por sua vez, integrar informaçöes acerca dos aspectos sensoriais dos estímulos com os sinais de origem periférica que refletem o estado homeoestático do organismo

Under-nutrition in older people: a serious and growing global problem!

Everyone agrees that adequate nutrient intake is important to all living things. Without food or water, life on earth would cease to exist. In the field of medical health, some gains have been made in meeting maternal and child nutritional needs. There is great community awareness regarding the importance of meeting the nutritional needs of the developing foetus and child. Malnutrition secondary to decreased intake in older people and weight loss is also a serious problem with unfortunately, very little notice from the community at large. As one ages, several physiological processes may contribute towards the development of protein energy malnutrition. Under-nutrition in older people is sadly far too common, even in developed countries. It is very likely that the same concerted effort used to address child malnutrition is required to combat under-nutrition in our elders. Protein energy malnutrition in older people comes at a significant cost to the individual, families, communities and the healthcare system. Failure to address this syndrome is not only unethical and unhealthy, but also costly. Vigilance and community awareness is important in ensuring that this important syndrome is detected and managed appropriately. This review mainly attempts to describe the pathophysiology, prevalence and consequences of under-nutrition and aims to highlight the importance of this clinical syndrome and the recent growth in our understanding of the processes behind its development. Some management strategies are also briefly described.