RESUMEN
Fundamento: Alta ingestão de lipídeos e colesterol compõe a dieta da sociedade moderna e está envolvida com o desenvolvimento de doenças cardiometabólicas. Entretanto, há lacunas na literatura quanto à existência de modelos de dislipidemias em ratos Wistar. Objetivos: Analisar o perfil cardiometabólico de ratos Wistar alimentados com dieta hiperlipídica e hipercolesterolêmica por seis semanas. Métodos: Ratos Wistar jovens foram alimentados com dieta hiperlipídica e hipercolesterolêmica por seis semanas para induzir a hiperlipidemia. Os ratos foram submetidos à cateterização da artéria carótida para determinar a pressão arterial. Após jejum, amostras de sangue foram coletadas por meio do cateter, e as concentrações de colesterol total, colesterol HDL, triglicerídeos e glicose foram determinadas. Amostras do tecido cardíaco foram removidas para análise histológica, a fim de se verificar a hipertrofia ventricular. Resultados: A ingestão da dieta por seis semanas foi eficaz em induzir alterações cardiometabólicas. O perfil dislipidêmico apresentado pelos ratos Wistar foi acompanhado de hiperinsulinemia, hipertensão moderada e hipertrofia ventricular do coração. Não houve alterações na glicemia. Conclusões: A administração de dieta hiperlipídica e hipercolesterolêmica em ratos Wistar jovens por seis semanas induziram alterações cardiometabólicas tornando-se um modelo eficaz para distúrbios dessa natureza
Background: The diet of modern society is composed by large intakes of lipids and cholesterol, involved in the development of cardiometabolic diseases. However, there are gaps in the literature regarding the existence of dyslipidemia models in Wistar rats. Objectives: To analyze the cardiometabolic profile of Wistar rats on a six-week hyperlipidic, hypercholesterolemic diet. Methods: Young Wistar rats were kept on a hyperlipidic, hypercholesterolemic diet for six weeks to induce hyperlipidemia. The rats underwent catheterization of the carotid artery to determine blood pressure. After fasting, blood samples were drawn through the catheter, and concentrations of total cholesterol, HDL cholesterol, triglycerides and glucose were determined. Cardiac tissue samples were taken for a histological analysis to check for ventricular hypertrophy. Results: The six-week diet was effective in inducing cardiometabolic alterations. The dyslipidemic profile presented by the Wistar rats was accompanied by hyperinsulinemia, moderate hypertension and cardiac ventricular hypertrophy. There were no alterations in glycemia. Conclusion: The six-week hyperlipidic, hypercholesterolemic diet in young Wistar rats induced cardiometabolic alterations, becoming an effective model for disorders of this nature
Asunto(s)
Animales , Ratas , Restricción Calórica , Dieta Alta en Grasa/métodos , Hipercolesterolemia , Hipercolesterolemia/sangre , Ratas Wistar , Presión Arterial , Enfermedades Cardiovasculares/metabolismo , Cateterismo/métodos , Técnicas Histológicas/métodos , Hipertrofia Ventricular Izquierda , Resultado del TratamientoRESUMEN
Aqueous extracts of Croton cajucara bark are used in folk medicine to treat hepatic and gastrointestinal disorders and as a coadjuvant in weight-loss programs. We examined the effect of treating rats for 15 days with a 5% aqueous extract of C. cajucara on body weight and food intake. The epididymal adipose pads were removed and the lipolytic responses of isolated adipocytes to isoprenaline, noradrenaline (norepinephrine), BRL37344 and adrenaline (epinephrine) were analysed in the absence or presence of metoprolol or ICI118,551. Treated rats had a significantly lower weight gain than control rats, with no difference in food and liquid intake, epididymal fat-pad weight or basal glycerol release. The sensitivity of the lipolytic response to isoprenaline and adrenaline was significantly higher in adipocytes from treated rats. The sensitivity to noradrenaline or BRL37344 was unaltered. Metoprolol shifted the dose-response curves to noradrenaline to the right in adipocytes from control and treated rats; the dose-response curve to isoprenaline in adipocytes from control rats was also shifted to the right. In adipocytes from treated rats, the dose-response curve to isoprenaline was unaltered by metoprolol but was shifted to the right by ICI118,551, a beta(2)-adrenoceptor antagonist. We conclude that in adipocytes from treated rats there is an increase in the lipolytic response to non-selective agonists (isoprenaline and adrenaline) mediated by beta(2)-adrenoceptors, with no alteration in the responses mediated by beta(1)-adrenoceptors (noradrenaline) or beta(3)-adrenoceptors (BRL37344). This effect could increase the role of adrenaline as an endogenous stimulator of lipolysis.