RESUMO
Obesity and dyslipidemias are both signs of metabolic syndrome, usually associated with ventricular arrhythmias. Here, we tried to identify cardiac electrical alteration and biomarkers in nonobese rats with metabolic syndrome (MetS), and these findings might lead to more lethal arrhythmias than obese animals. The MetS model was developed in Wistar rats with high-sucrose diet (20%), and after twenty-eight weeks were obtained two subgroups: obese (OMetS) and nonobese (NOMetS). The electrocardiogram was used to measure the ventricular arrhythmias and changes in the heart rate variability. Also, we measured ventricular hypertrophy and its relationship with electrical activity alterations of both ventricles, using micro-electrode and voltage clamp techniques. Also, we observed alterations in the contraction force of ventricles where a transducer was used to record mechanical and electrical papillary muscle, simultaneously. Despite both subgroups presenting long QT syndrome (0.66 ± 0.05 and 0.66 ± 0.07 ms with respect to the control 0.55 ± 0.1 ms), the changes in the heart rate variability were present only in OMetS, while the NOMetS subgroup presented changes in QT interval variability (NOMetS SD = 1.8, SD2 = 2.8; SD1/SD2 = 0.75). Also, the NOMetS revealed tachycardia (10%; p < 0.05) with changes in action potential duration (63% in the right papillary and 50% in the left papillary) in the ventricular papillary which are correlated with certain alterations in the potassium currents and the force of contraction. The OMetS showed an increase in action potential duration and the force of contraction in both ventricles, which are explained as bradycardia. Our results revealed lethal arrhythmias in both MetS subgroups, irrespectively of the presence of obesity. Consequently, the NOMetS showed mechanical-electrical alterations regarding ventricle hypertrophy that should be at the NOMetS, leading to an increase of CV mortality.
Assuntos
Síndrome Metabólica/complicações , Obesidade/complicações , Disfunção Ventricular/fisiopatologia , Animais , Modelos Animais de Doenças , Síndrome Metabólica/fisiopatologia , Obesidade/fisiopatologia , Ratos , Ratos Wistar/metabolismo , Disfunção Ventricular/etiologiaRESUMO
BACKGROUND: Early postnatal overfeeding (PO) induces long-term overweight and reduces brown adipose tissue (BAT) thermogenesis. Exercise has been suggested as a possible intervention to increase BAT function. In this study, we investigated chronical effects of moderate-intensity exercise in BAT function in postnatal overfed male Wistar rats METHODS: Litters' delivery was on postnatal-day 0 - PN0. At PN2, litters were adjusted to nine (normal litter - NL) or three pups (small litter - SL) per dam. Animals were weaned on PN21 and in PN30 randomly divided into sedentary (NL-Sed and SL-Sed) or exercised (NL-Exe and SL-Exe), N of 14 litters per group. Exercise protocol started (PN30) with an effort test; training sessions were performed three times weekly at 60% of the VO2max achieved in effort test, until PN80. On PN81, a temperature transponder was implanted beneath the interscapular BAT, whose temperature was assessed in periods of lights-on and -off from PN87 to PN90. Sympathetic nerve activation of BAT was registered at PN90. Animals were euthanized at PN91 and tissues collected RESULTS: PO impaired BAT thermogenesis in lights-on (pPO < 0.0001) and -off (pPO < 0.01). Exercise increased BAT temperature in lights-on (pExe < 0.0001). In NL-Exe, increased BAT activity was associated with higher sympathetic activity (pExe < 0.05), ß3-AR (pExe < 0.001), and UCP1 (pExe < 0.001) content. In SL-Exe, increasing BAT thermogenesis is driven by a combination of tissue morphology remodeling (pExe < 0.0001) with greater effect in increasing UCP1 (pExe < 0.001) and increased ß3-AR (pExe < 0.001) content. CONCLUSION: Moderate exercise chronically increased BAT thermogenesis in both, NL and SL groups. In NL-Exe by increasing Sympathetic activity, and in SL-Exe by a combination of increased ß3-AR and UCP1 content with morphologic remodeling of BAT. Chronically increasing BAT thermogenesis in obese subjects may lead to higher overall energy expenditure, favoring the reduction of obesity and related comorbidities.
Assuntos
Tecido Adiposo Marrom/metabolismo , Obesidade/fisiopatologia , Condicionamento Físico Animal/fisiologia , Animais , Brasil , Modelos Animais de Doenças , Camundongos , Obesidade/diagnóstico , Condicionamento Físico Animal/métodos , Ratos Wistar/crescimento & desenvolvimento , Ratos Wistar/metabolismoRESUMO
The consumption of fructose has increased in children and adolescents and is partially responsible for the high incidence of metabolic diseases. The lifestyle during postnatal development can result in altered metabolic programming, thereby impairing the reproductive system and fertility during adulthood. Therefore, the aim of this study was to evaluate the effect of a high-fructose diet in the male reproductive system of pubertal and adult rats. Male Wistar rats (30 d old) were assigned to four different groups: Fr30, which received fructose (20%) in water for 30 d and were euthanized at postnatal day (PND) 60; Re-Fr30, which received fructose (20%) for 30 d and were euthanized at PND 120; and two control groups C30 and Re-C30, which received water ad libitum and were euthanized at PND 60 and 120, respectively. Fructose induced an increase in abnormal seminiferous tubules with epithelial vacuoles, degeneration, and immature cells in the lumen. Moreover, Fr30 rats showed altered spermatogenesis and daily sperm production (DSP), as well as increased serum testosterone concentrations. After discontinuing high-fructose consumption, DSP and sperm number decreased significantly. We observed tissue remodeling in the epididymis, with a reduction in stromal and epithelial compartments that might have influenced sperm motility. Therefore, we concluded that fructose intake in peripubertal rats led to changes in the reproductive system observed both during puberty and adulthood.
Assuntos
Epididimo/patologia , Qualidade dos Alimentos , Xarope de Milho Rico em Frutose/efeitos adversos , Testículo/patologia , Animais , Modelos Animais de Doenças , Epididimo/efeitos dos fármacos , Epididimo/fisiopatologia , Xarope de Milho Rico em Frutose/metabolismo , Masculino , Puberdade/sangue , Puberdade/metabolismo , Ratos Wistar/crescimento & desenvolvimento , Ratos Wistar/metabolismo , Contagem de Espermatozoides/métodos , Contagem de Espermatozoides/estatística & dados numéricos , Testículo/efeitos dos fármacos , Testículo/fisiopatologia , Testosterona/análise , Testosterona/sangueRESUMO
Early weaning (EW) is associated with obesity later in life. Here, using an EW model in rats, we investigated changes in feeding behavior and the dopaminergic and endocannabinoid systems (ECS) in the adult offspring. Lactating Wistar rats were divided into two groups: EW, dams were wrapped with a bandage to interrupt suckling during the last 3 days of breastfeeding; CONT; dams fed the pups throughout the period without hindrances. EW animals were compared with CONT animals of the same sex. At PN175, male and female offspring of both groups could freely self-select between high-fat and high-sugar diets (food challenge test). EW males preferred the high-fat diet at 30 min and more of the high-sugar diet after 12 h compared to CONT males. EW females did not show differences in their preference for the palatable diets compared to CONT females. Total intake of standard diet from PN30-PN180 was higher in both male and female EW animals, indicating hyperphagia. At PN180, EW males showed lower type 2 dopamine receptor (D2r) in the nucleus accumbens (NAc) and dorsal striatum, while EW females had lower tyrosine hydroxylase in the ventral tegmental area and NAc, D1r in the NAc, and D2r in the prefrontal cortex. In the lateral hypothalamus, EW males had lower fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase, whereas EW females showed lower N-arachidonoyl-phosphatidylethanolamine phospholipase-D and increased FAAH. Early weaning altered both the dopaminergic and ECS parameters at adulthood, contributing to the eating behavior changes of the progeny in a sex-dependent manner.
Assuntos
Dopaminérgicos/metabolismo , Endocanabinoides/metabolismo , Preferências Alimentares/psicologia , Fatores de Tempo , Desmame , Análise de Variância , Animais , Modelos Animais de Doenças , Comportamento Alimentar , Ratos , Ratos Wistar/metabolismoRESUMO
Lifestyle and heredity are two different terms but yet closely related components. An evaluation for the time invested in sleep and locomotion behaviors per second in the Wistar rats animal model was carried out. A total of six rats within the same cage were marked by color in a room supported by the days light (12h lighting/12h darkness). These animals were filmed for 18 h daily for ten days (9h lighting, 9h darkness) to estimate the time budget of sleep and locomotion behaviors and the temporal distribution taking into account the nature of this biological models activity. The results obtained reveal sleeping/locomotion cycles respecting the natural photoperiod except for a rat that shows dominance in nocturnal sleep compared to the rest of the rats. These advances support a change in photoperiodic behavior in response to an adaptation to the rhythm imposed by the manipulator. They invite studies on a larger sample to consolidate this behavior controlled by the environment.
Assuntos
Animais , Camundongos , Comportamento Animal/fisiologia , Ratos Wistar/metabolismo , Ritmo Circadiano/fisiologiaRESUMO
Lifestyle and heredity are two different terms but yet closely related components. An evaluation for the time invested in sleep and locomotion behaviors per second in the Wistar rats animal model was carried out. A total of six rats within the same cage were marked by color in a room supported by the days light (12h lighting/12h darkness). These animals were filmed for 18 h daily for ten days (9h lighting, 9h darkness) to estimate the time budget of sleep and locomotion behaviors and the temporal distribution taking into account the nature of this biological models activity. The results obtained reveal sleeping/locomotion cycles respecting the natural photoperiod except for a rat that shows dominance in nocturnal sleep compared to the rest of the rats. These advances support a change in photoperiodic behavior in response to an adaptation to the rhythm imposed by the manipulator. They invite studies on a larger sample to consolidate this behavior controlled by the environment.(AU)
Assuntos
Animais , Camundongos , Ratos Wistar/metabolismo , Ritmo Circadiano/fisiologia , Comportamento Animal/fisiologiaRESUMO
Reserpine (RES) is an irreversible inhibitor of VMAT2 used to study Parkinson's disease (PD) and screening for antiparkinsonian treatments in rodents. Recently, the repeated treatment with a low dose of reserpine was proposed as a model capable of emulating progressive neurochemical, motor and non-motor impairments in PD. Conversely, compared to Wistar rats, Spontaneously Hypertensive Rats (SHR) are resistant to motor changes induced by repeated treatment with a low dose of RES. However, such resistance has not yet been investigated for RES-induced non-motor impairments. We aimed to assess whether SHR would have differential susceptibility to the object recognition deficit induced by repeated low-dose reserpine treatment. We submitted male Wistar and SHR rats to repeated RES treatment (15 s.c. injections of 0.1 mg/kg, every other day) and assessed object memory acquisition and retrieval 48 h after the 6th RES injection (immediately before the appearance of motor impairments). Only RES Wistar rats displayed memory impairment after reserpine treatment. On the other hand, untreated SHR rats displayed object recognition memory deficit, but RES treatment restored such deficits. We also performed immunohistochemistry for tyrosine hydroxylase (TH) and α-synuclein (α-syn) 48 h after the last RES injection. In a different set of animals submitted to the same treatment, we quantified DA, 5-HT and products of lipid peroxidation in the prefrontal cortex (PFC) and hippocampus (HPC). SHR presented increased constitutive levels of DA in the PFC and reduced immunoreactivity to TH in the medial PFC and dorsal HPC. Corroborating the behavioral findings, RES treatment restored those constitutive alterations in SHR. These findings indicate that the neurochemical, molecular and genetic differences in the SHR strain are potentially relevant targets to the study of susceptibility to diseases related to dopaminergic alterations.
Assuntos
Transtornos Cognitivos/induzido quimicamente , Dopamina/metabolismo , Hipocampo , Doença de Parkinson Secundária/induzido quimicamente , Córtex Pré-Frontal , Reconhecimento Psicológico/efeitos dos fármacos , Reserpina/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo , Proteínas Vesiculares de Transporte de Monoamina/antagonistas & inibidores , Animais , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Endogâmicos SHR/metabolismo , Ratos Wistar/metabolismo , Reserpina/administração & dosagem , Transdução de Sinais/efeitos dos fármacosRESUMO
This study aims to evaluate the effect of fenugreek on biochemical parameters, body weight, and the behavior of male Wistar rats. The purpose of administering the aqueous extract of fenugreek seeds (Trigonella foenum-graecum L) for 30 successive days by oral gavage (force-feeding) at a dose of 250g / l of water is intended to assess, on the one hand, the neurobehavioural effects and on the other hand its effect on some biochemical parameters (glycemia and lipid balance) as well as weight. The behavioral tests performed are the Light/Dark Box tests (LDB) and the Elevated Plus Maze test (EPM). This work indicated that the consumption of the aqueous extract of the seeds of fenugreek is beneficial to stimulate appetite and gain weight, thus decreasing the level of total cholesterol, triglycerides, LDL-C, and a significant increase in HDL-C, also a reduction in blood sugar and a decrease in anxiety.
Assuntos
Masculino , Animais , Ratos , Comportamento Animal , Nutrição Enteral/veterinária , Ratos Wistar/crescimento & desenvolvimento , Ratos Wistar/metabolismo , Ratos Wistar/sangue , Trigonella/efeitos adversosRESUMO
This study aims to evaluate the effect of fenugreek on biochemical parameters, body weight, and the behavior of male Wistar rats. The purpose of administering the aqueous extract of fenugreek seeds (Trigonella foenum-graecum L) for 30 successive days by oral gavage (force-feeding) at a dose of 250g / l of water is intended to assess, on the one hand, the neurobehavioural effects and on the other hand its effect on some biochemical parameters (glycemia and lipid balance) as well as weight. The behavioral tests performed are the Light/Dark Box tests (LDB) and the Elevated Plus Maze test (EPM). This work indicated that the consumption of the aqueous extract of the seeds of fenugreek is beneficial to stimulate appetite and gain weight, thus decreasing the level of total cholesterol, triglycerides, LDL-C, and a significant increase in HDL-C, also a reduction in blood sugar and a decrease in anxiety.(AU)
Assuntos
Animais , Masculino , Ratos , Ratos Wistar/sangue , Ratos Wistar/crescimento & desenvolvimento , Ratos Wistar/metabolismo , Trigonella/efeitos adversos , Comportamento Animal , Nutrição Enteral/veterináriaRESUMO
The hypothesis was that maternal intake of the antioxidant alpha-lipoid acid (ALA), during the developmental period of the hypothalamic orexigenic neurons, causes a permanent beneficial effect in offspring metabolism. Pregnant Wistar rats were fed with standard diet (food) + ALA (0.4% wt/wt) from day 14 of gestation to day 20 of lactation (n = 4) or food (n = 4). At 3 months of age, male offspring born from ALA-fed rats or controls (CT) were randomly assigned to be fed with food + 10% fructose solution in drinking water (F) or food + tap water (C), resulting in four groups: ALAF, ALAC, CTF, and CTC (n = 5/group). Food intake and body weight (BW) were measured twice a week for 31 days. Metabolites' levels in blood, mRNA expressions of Npy, Agrp (hypothalamus), Fasn, Srebf1, Ppard, and Pparg (liver), and the antioxidant capacity of the liver were determined. Results significance was set at p < 0.05. Average BW gain, daily BW gain, and intraabdominal fat tissue at necropsy were higher in CTF group followed by CTC, ALAF, and ALAC groups. There were no differences between groups in Kcal intake per day. mRNA expressions of hypothalamic and hepatic genes and plasmatic levels of glucose and triglycerides were higher in CTF group followed by ALAF, CTC, and ALAC groups. Fructose intake affected the oxidative capacity of the liver, but this effect was not observed in the ALAF group. In conclusion, maternal ALA intake protected the adult offspring to develop metabolic symptoms associated with high fructose in the drinking water.