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1.
Chemosphere ; 335: 139010, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37236281

RESUMO

Heavy metals (HMs) and metalloids (Ms) such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) represent serious environmental threats due to their wide abundance and high toxicity. Contamination of water and soils by HMs and Ms from natural or anthropogenic sources is of great concern in agricultural production due to their toxic effects on plants, adversely affecting food safety and plant growth. The uptake of HMs and Ms by Phaseolus vulgaris L. plants depends on several factors including soil properties such as pH, phosphate, and organic matter. High concentrations of HMs and Ms could be toxic to plants due to the increased generation of reactive oxygen species (ROS) such as (O2•-), (•OH), (H2O2), and (1O2), and oxidative stress due to an imbalance between ROS generation and antioxidant enzyme activity. To minimize the effects of ROS, plants have developed a complex defense mechanism based on the activity of antioxidant enzymes such as SOD, CAT, GPX, and phytohormones, especially salicylic acid (SA) that can reduce the toxicity of HMs and Ms. This review focuses on evaluating the accumulation and translocation of As, Cd, Hg, and Pb in Phaseolus vulgaris L. plants and on their possible effects on the growth of Phaseolus vulgaris L. in soil contaminated with these elements. The factors that affect the uptake of HMs and Ms by bean plants, and the defense mechanisms under oxidative stress caused by the presence of As, Cd, Hg, and Pb are also discussed. Furthermore, future research on mitigating HMs and Ms toxicity in Phaseolus vulgaris L. plants is highlighted.


Assuntos
Arsênio , Mercúrio , Metaloides , Metais Pesados , Phaseolus , Poluentes do Solo , Cádmio/toxicidade , Espécies Reativas de Oxigênio/farmacologia , Antioxidantes/farmacologia , Peróxido de Hidrogênio/farmacologia , Chumbo/farmacologia , Poluentes do Solo/análise , Metais Pesados/análise , Arsênio/análise , Mercúrio/toxicidade , Plantas , Solo/química
2.
Mol Metab ; 30: 72-130, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31767182

RESUMO

BACKGROUND: The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent ß-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity. SCOPE OF REVIEW: In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases. MAJOR CONCLUSIONS: Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders.


Assuntos
Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Polipeptídeo Inibidor Gástrico/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Glucose/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Obesidade/metabolismo , Receptores de Glucagon/metabolismo
3.
Obes Rev ; 17(9): 795-809, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27272117

RESUMO

Bariatric surgery is currently the most effective treatment for obesity. Not only do these types of surgeries produce significant weight loss but also they improve insulin sensitivity and whole body metabolic function. The aim of this review is to explore how altered physiology of adipose tissue may contribute to the potent metabolic effects of some of these procedures. This includes specific effects on various fat depots, the function of individual adipocytes and the interaction between adipose tissue and other key metabolic tissues. Besides a dramatic loss of fat mass, bariatric surgery shifts the distribution of fat from visceral to the subcutaneous compartment favoring metabolic improvement. The sensitivity towards lipolysis controlled by insulin and catecholamines is improved, adipokine secretion is altered and local adipose inflammation as well as systemic inflammatory markers decreases. Some of these changes have been shown to be weight loss independent, and novel hypothesis for these effects includes include changes in bile acid metabolism, gut microbiota and central regulation of metabolism. In conclusion bariatric surgery is capable of improving aspects of adipose tissue function and do so in some cases in ways that are not entirely explained by the potent effect of surgery. © 2016 World Obesity.


Assuntos
Tecido Adiposo/fisiologia , Cirurgia Bariátrica , Obesidade/cirurgia , Adipócitos/metabolismo , Adipocinas/sangue , Adipocinas/metabolismo , Animais , Catecolaminas/sangue , Modelos Animais de Doenças , Humanos , Inflamação , Insulina/sangue , Resistência à Insulina
4.
Int J Obes (Lond) ; 39(8): 1310-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25869599

RESUMO

BACKGROUND/OBJECTIVES: Mounting evidence supports a link between circadian disruption and metabolic disease. Humans with circadian disruption (for example, night-shift workers) have an increased risk of obesity and cardiometabolic diseases compared with the non-disrupted population. However, it is unclear whether the obesity and obesity-related disorders associated with circadian disruption respond to therapeutic treatments as well as individuals with other types of obesity. SUBJECTS/METHODS: Here, we test the effectiveness of the commonly used bariatric surgical procedure, Vertical Sleeve Gastrectomy (VSG), in mouse models of genetic and environmental circadian disruption. RESULTS: VSG led to a reduction in body weight and fat mass in both Clock(Δ19) mutant and constant-light mouse models (P<0.05), resulting in an overall metabolic improvement independent of circadian disruption. Interestingly, the decrease in body weight occurred without altering diurnal feeding or activity patterns (P>0.05). Within circadian-disrupted models, VSG also led to improved glucose tolerance and lipid handling (P<0.05). CONCLUSIONS: Together these data demonstrate that VSG is an effective treatment for the obesity associated with circadian disruption, and that the potent effects of bariatric surgery are orthogonal to circadian biology. However, as the effects of bariatric surgery are independent of circadian disruption, VSG cannot be considered a cure for circadian disruption. These data have important implications for circadian-disrupted obese patients. Moreover, these results reveal new information about the metabolic pathways governing the effects of bariatric surgery as well as of circadian disruption.


Assuntos
Gastrectomia , Obesidade/metabolismo , Privação do Sono/metabolismo , Animais , Ritmo Circadiano , Modelos Animais de Doenças , Metabolismo Energético , Camundongos , Privação do Sono/fisiopatologia , Redução de Peso
5.
Int J Obes (Lond) ; 38(2): 192-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23736358

RESUMO

BACKGROUND: Obesity has a complicated metabolic pathology, and defining the underlying mechanisms of obesity requires integrative studies with molecular end points. Real-time quantitative PCR (RT-qPCR) is a powerful tool that has been widely utilized. However, the importance of using carefully validated reference genes in RT-qPCR seems to have been overlooked in obesity-related research. The objective of this study was to select a set of reference genes with stable expressions to be used for RT-qPCR normalization in rats under fasted vs re-fed and chow vs high-fat diet (HFD) conditions. DESIGN: Male long-Evans rats were treated under four conditions: chow/fasted, chow/re-fed, HFD/fasted and HFD/re-fed. Expression stabilities of 13 candidate reference genes were evaluated in the rat hypothalamus, duodenum, jejunum and ileum using the ReFinder software program. The optimal number of reference genes needed for RT-qPCR analyses was determined using geNorm. RESULTS: Using geNorm analysis, we found that it was sufficient to use the two most stably expressed genes as references in RT-qPCR analyses for each tissue under specific experimental conditions. B2M and RPLP0 in the hypothalamus, RPS18 and HMBS in the duodenum, RPLP2 and RPLP0 in the jejunum and RPS18 and YWHAZ in the ileum were the most suitable pairs for a normalization study when the four aforementioned experimental conditions were considered. CONCLUSIONS: Our study demonstrates that gene expression levels of reference genes commonly used in obesity-related studies, such as ACTB or RPS18, are altered by changes in acute or chronic energy status. These findings underline the importance of using reference genes that are stable in expression across experimental conditions when studying the rat hypothalamus and intestine, because these tissues have an integral role in the regulation of energy homeostasis. It is our hope that this study will raise awareness among obesity researchers on the essential need for reference gene validation in gene expression studies.


Assuntos
Hipotálamo/metabolismo , Mucosa Intestinal/metabolismo , Obesidade/genética , Proteínas Ribossômicas/metabolismo , Animais , Dieta Hiperlipídica , Jejum , Perfilação da Expressão Gênica , Marcadores Genéticos , Masculino , Obesidade/metabolismo , Ratos , Ratos Long-Evans , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Ribossômicas/genética
6.
Int J Obes (Lond) ; 37(2): 288-95, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22334194

RESUMO

OBJECTIVE: Diets high in fat are implicated in the development and maintenance of obesity, and obese individuals display greater preferences for high-fat foods than do their lean counterparts. Weight-reduction bariatric surgery is associated with changes in food choice. In particular, after Roux-en-Y gastric bypass (RYGB), humans and rodents select or prefer foods that are lower in fat content. We asked whether a bariatric surgical procedure limited to the stomach, vertical sleeve gastrectomy (VSG), causes a similar reduction of fat intake/preference. RESEARCH DESIGN AND METHODS: Rats received VSG or Sham surgery or remained surgically naïve, and were assessed for food preference using three diet-choice paradigms. Using progressive-ratio (PR) and conditioned taste aversion paradigms, we further asked whether surgically induced changes in food choice are secondary to changes in the reward value of food and/or to the formation of a food aversion. Finally, food choice was compared between VSG- and RYGB-operated rats. RESULTS: VSG rats decreased their intake of dietary fat, and shifted their preference toward lower caloric-density foods. This change in food choice was not associated with changes in motivated responding on a PR schedule for either a fat or a carbohydrate food reinforcer. When VSG and RYGB were compared directly, both procedures caused comparable changes in food choice. The conditioned taste aversion paradigm revealed that VSG rats form an aversion to an intra-gastric oil administration whereas RYGB rats do not. CONCLUSIONS: VSG and RYGB, two anatomically distinct bariatric procedures, produce similar changes in food choice.


Assuntos
Gorduras na Dieta/metabolismo , Preferências Alimentares , Derivação Gástrica , Gastroplastia , Obesidade/cirurgia , Animais , Peso Corporal , Comportamento de Escolha , Metabolismo Energético , Masculino , Condicionamento Físico Animal , Ratos , Ratos Long-Evans , Recompensa , Paladar
7.
Nutr Diabetes ; 2: e27, 2012 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-23169552

RESUMO

OBJECTIVES: Because females have blunted counterregulatory responses to hypoglycemia relative to males, we hypothesized that females would have greater sensitivity to changes in lipid availability. DESIGN AND SUBJECTS: To assess this, we examined the feeding response to glucoprivation (2-deoxyglucose; 2DG) and lipoprivation (mercaptoacetate; MA) in age-matched male and female Long-Evans rats. RESULTS: Males versus females had significantly greater food intake after 250 mg kg(-1) of 2DG, but there were no sex differences with the 750 mg kg(-1) dose of 2DG. Glucose responses to 250 mg kg(-1) of 2DG were also significantly greater in males versus females. In contrast, females had a significant increase in food intake with all doses of MA versus saline, and had significantly greater food intake compared with males at the lowest and highest doses of MA with a trend towards significance with the intermediate dose. To determine whether estradiol (E2) is the mechanism underlying this sexual dimorphism, ovariectomized females were injected with vehicle or 2 µg of E2 every fourth day to mimic the variations in across the estrous cycle. Ovariectomized females significantly increased feeding and glucose after 250 mg kg(-1) of 2DG over intact females and E2 had no effect on these responses. Although the feeding response to 2DG was not different, the glucose response to 2DG was still significantly greater in males versus ovariectomies females. However, ovariectomized females also did not increase food intake after MA, regardless of E2 treatment. CONCLUSIONS: These data collectively suggest that males are relatively more sensitive to glucose deprivation and females are relatively more sensitive to lipid deprivation. Further, these data rule out a role for cyclic changes in E2 in these sex differences.

8.
Aviat Space Environ Med ; 72(8): 733-8, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11506235

RESUMO

BACKGROUND: Previous research has found that exercise exacerbated acute mountain sickness (AMS) in men. PURPOSE: The current study tested this relationship in women taking oral contraceptives. METHODS: We studied seven women at 428 mmHg for 10 h; once while at rest (R) and once while performing intermittent exercise (EX). RESULTS: AMS scores had a slight increase at 9 vs. 0 h at altitude in both trials (p < 0.05). Resting measurements of ventilation (VE), arterial oxygen saturation (SPO2), end tidal O2 (PETO2), and end tidal CO2 (PETCO2) were not different over time or between trials (p > 0.05). While fluid intake did not change, urine output increased during the 0-3 h period, regardless of trial, and returned to baseline values by the 6-9 h period (218 +/- 37 vs. 121 +/- 22 ml x h(-1); p < 0.05). During exercise, SPO2 significantly dropped compared with similar time points in R (73.1 +/- 1.1 vs. 85.7 +/- 1.8%; p < 0.05). Despite exercise-induced desaturation, the AMS scores were not significantly different between R and EX. CONCLUSION: These results suggest that oral contraceptives may cause a compensation for the physiological responses to exercise critical for the development of AMS.


Assuntos
Doença da Altitude/fisiopatologia , Anticoncepcionais Orais/farmacologia , Exercício Físico/fisiologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Adulto , Doença da Altitude/induzido quimicamente , Anticoncepcionais Orais/efeitos adversos , Feminino , Humanos , Consumo de Oxigênio/efeitos dos fármacos , Ventilação Pulmonar/fisiologia , Respiração/efeitos dos fármacos , Urina , Equilíbrio Hidroeletrolítico/fisiologia
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