ABSTRACT
Abstract Increased oxygen consumption and activation of specific metabolic pathways during or after physical exercise lead to the formation of reactive oxygen and nitrogen species. An investigation was made into the effects of pequi oil supplementation in protecting liver cells against injury resulting from oxidative stress. The experiments involved 20 male adult Wistar rats ( Rattus norvegicus). The animals were divided into four experimental groups: Group 1: sedentary control group; Group 2: exercise control group; Group 3: supplemented sedentary group; and Group 4: supplemented exercise group. Supplementation consisted of pequi oil administered by oral gavage (400 mg). The animals of the exercised groups were subjected to 20 swimming sessions for 5 weeks (with progressive increase of 10 minutes until exhaustion). Samples were collected from the right hepatic lobe for histopathological analysis and determination of malondialdehyde levels. The histopathological analyses revealed that the animals of the exercised control group had moderate liver damage, while the animals of the supplemented exercised group had slight tissue damage, and the sedentary control and sedentary supplemented groups showed no tissue damage. The malondialdehyde levels showed higher and statistically significant in exercise control group when compared to the other evaluated groups (p<0.05). In conclusion the supplementation with pequi oil had a protective effect on liver cells against damage caused by oxygen free radicals during strenuous exercise, as demonstrated by the indicator of lipid peroxidation.
Resumo Aumento do consumo de oxigênio e ativação de vias metabólicas específicas durante ou após a atividade física conduz para formação de espécies reativas de oxigênio e nitrogênio. Uma investigação foi realizada sobre os efeitos da suplementação com óleo de pequi na proteção das células hepáticas contra lesões resultantes do estresse oxidativo. Na realização dos experimentos foram utilizados 20 ratos machos adultos da linhagem Wistar (Rattus novergicus ). Os animais foram divididos em quatro grupos experimentais: grupo 1: grupo sedentário controle; grupo 2: grupo treinado controle; grupo 3: grupo sedentário suplementado e grupo 4: grupo treinado suplementado. Na suplementação foi utilizado o óleo de pequi ministrado por gavagem oral (400 mg). Os animais dos grupos treinados foram submetidos a 20 sessões de natação por um período de 5 semanas (com aumento progressivo de 10 minutos até a exaustão). Foram retiradas amostras do lobo hepático direito para análises histopatológicas, e dosagem de malondialdeído. As análises histopatológicas revelaram que os animais do grupo treinado controle tiveram danos hepáticos moderados; já os animais do grupo treinado suplementado tiveram danos teciduais leves; os grupos sedentário controle e sedentário suplementado não apresentaram injúrias teciduais. Os níveis de malondialdeído mostraram-se maiores e estatisticamente significativos no grupo treinado controle quando comparados aos outros grupos avaliados (p<0,05). Podemos concluir que a suplementação com óleo de pequi teve efeito protetor nas células hepáticas contra os danos causados pelos radicais livres de oxigênio durante os exercícios exaustivos, conforme demonstrado pelo indicador de peroxidação lipídica.
Subject(s)
Animals , Male , Rats , Swimming/physiology , Plant Oils/pharmacology , Ericales/chemistry , Liver/drug effects , Antioxidants/pharmacology , Rats, WistarABSTRACT
The present study sought to determine cardiovascular effects of aerobic training associated with diminazene aceturate (DIZE), an activator of the angiotensin converting enzyme 2, in spontaneously hypertensive rats (SHRs). Male SHRs (280–350 g) were either subjected to exercise training or not (sedentary group). The trained group was subjected to 8 weeks of aerobic training on a treadmill (five times a week, lasting 60 min at an intensity of 50–60% of maximum aerobic speed). In the last 15 days of the experimental protocol, these groups were redistributed into four groups: i) sedentary SHRs with daily treatment of 1 mg/kg DIZE (S+D1); ii) trained SHRs with daily treatment of 1 mg/kg DIZE (T+D1); iii) sedentary SHRs with daily treatment of vehicle (S+V); and iv) trained SHRs with daily treatment of vehicle (T+V). After treatment, SHRs were anesthetized and subjected to artery and femoral vein cannulation prior to the implantation of ECG electrode. After 24 h, mean arterial pressure (MAP) and heart rate (HR) were recorded; the baroreflex sensitivity and the effect of double autonomic blockade (DAB) were evaluated in non-anesthetized SHRs. DIZE treatment improved baroreflex sensitivity in the T+D1 group as compared with the T+V and S+D1 groups. The intrinsic heart rate (IHR) and MAP were reduced in T+D1 group as compared with T+V and S+D1 groups. Hence, we conclude that the association of exercise training with DIZE treatment improved baroreflex function and cardiovascular regulation.
Subject(s)
Animals , Male , Rats , Baroreflex/drug effects , Diminazene/analogs & derivatives , Hypertension/drug therapy , Peptidyl-Dipeptidase A/pharmacology , Physical Conditioning, Animal/physiology , Blood Pressure/physiology , Diminazene/agonists , Diminazene/pharmacology , Heart Rate/physiology , Hypertension/physiopathology , Rats, Inbred SHR , Signal Transduction/drug effectsABSTRACT
OBJETIVO: Avaliar a influência do uso de contraceptivos orais (CO) sobre os níveis lipídicos, a variabilidade da freqüência cardíaca (VFC) e a capacidade aeróbia em mulheres jovens sedentárias. MATERIAIS E MÉTODOS: Vinte mulheres saudáveis (23,55±1,88 anos), sendo dez que utilizam CO (GT) e dez que não utilizam CO (GC). Protocolos: teste ergoespirométrico (TE), em cicloergômetro para determinar a capacidade aeróbia no limiar de anaerobiose (LA) e no pico do exercício; captação da FC e dos intervalos R-R (iRR) nas posições supina e sentada durante 15 minutos; análise bioquímica de sangue. Os índices dos iRR(ms) foram analisados no domínio do tempo (DT), RMSSD, RMSM e pNN50( por cento) e no domínio da freqüência (DF), usando a transformada rápida de Fourier a partir das bandas de baixa freqüência (BF) e alta freqüência (AF), em unidades normalizadas (un), e a razão a BF/AF. Estatística: Mann-Whitney e Kruskal-Wallis, α=5 por cento. RESULTADOS: Os níveis de triglicérides e de colesterol do GT foram superiores aos do GC (p<0,05). No LA e no pico do exercício, a potência (W), o consumo de oxigênio, a produção de dióxido de carbono, a razão VO2/VCO2, a ventilação pulmonar e a freqüência cardíaca (FC) foram semelhantes (p>0,05) entre os grupos. Os índices da VFC no DT e no DF da posição supina e sentada intergrupos foram semelhantes. CONCLUSÕES: O uso de CO não influenciou na capacidade aeróbia e na modulação autonômica da FC, mas influenciou nos níveis de colesterol total e triglicérides. Estas avaliações são importantes para a determinação de protocolos de treinamento físico na prevenção de doenças cardiovasculares.
OBJECTIVE: To evaluate the influence of oral contraceptive use on lipid levels, heart rate (HR) variability and aerobic capacity among sedentary young women. METHODS: The subjects were 20 healthy women (23.55±1.88 years): ten used oral contraceptives (TG) and ten did not (CG). Ergospirometric test on a cycle ergometer was used to determine the aerobic capacity at the anaerobic threshold and at the exercise peak. In addition, recordings of HR and R-R (iRR) intervals in the supine and seated positions, for 15 minutes, and biochemical blood analysis were performed. The iRR (ms) indices were analyzed in the time domain (TD) for RMSSD, RMSM and pNN50 ( percent), and in the frequency domain (FD) using fast Fourier transforms from low (LF) and high (HF) frequency bands in normalized units, obtaining the LF/HF ratio. Mann-Whitney and Kruskal-Wallis, with α=5 percent, were used for statistical analyses. RESULTS: The triglyceride and cholesterol levels in the TG were greater than those in the CG (p<0.05). At the anaerobic threshold and at the exercise peak, the power (W), oxygen uptake (VO2), carbon dioxide production (VCO2), (VO2/VCO2) ratio, pulmonary ventilation and HR were not significantly different between the groups. The indices for HR variability in the TD and FD for the two groups in the supine and seated positions were also not different. CONCLUSIONS: The use of oral contraceptives did not influence the aerobic capacity or the autonomic modulation of the HR. However, it influenced the total cholesterol and triglyceride levels. These assessments are important for determining protocols for physical training for cardiovascular disease prevention.