A Malária e o Endotélio Vascular

O acometimento do sistema cardiovascular em pacientes com doenças infecciosas e parasitárias pode ocorrer tanto por mecanismos intrínsecos à doença como em decorrência de intervenção medicamentosa. A malária é uma dessas doenças, tendo em vista que a agressão endotelial generalizada que se observa na infecção por Plasmodium pode causar distúrbios circulatórios. O objetivo deste artigo é discutir a relação entre malária e o comprometimento endotelial, em especial suas consequências sobre o sistema cardiovascular, a partir de uma revisão da literatura. Discutem-se as repercussões da agressão endotelial, bem como a interdisciplinaridade que deve nortear a atenção ao paciente malárico cuja infecção aguda pode contribuir para precipitar ou agravar doença cardíaca preexistente.Involvement of the cardiovascular system in patients with infectious and parasitic diseases can result from both intrinsic mechanisms of the disease and drug intervention. Malaria is an example, considering that the endothelial injury by Plasmodium-infected erythrocytes can cause circulatory disorders. This is a literature review aimed at discussing the relationship between malaria and endothelial impairment, especially its effects on the cardiovascular system. We discuss the implications of endothelial aggression and the interdisciplinarity that should guide the malaria patient care, whose acute infection can contribute to precipitate or aggravate a preexisting heart disease

Blockade of renin-angiotensin system attenuates cardiac remodeling in rats undergoing aortic stenosis

OBJETIVO: Avaliar o papel do bloqueador dos receptores AT1 e do inibidor da enzima conversora da angiotensina na remodelação cardíaca induzida por estenose aórtica em ratos. MÉTODOS: Ratos Wistar foram divididos em 4 grupos: controle (C, n=13), estenose aórtica (EAo, n=11), EAo com lisinopril, 20 mg/kg/dia (LIS, n=11) e EAo com losartan, 40 mg/kg/dia (LOS, n=9). Os tratamentos foram iniciados 3 dias antes da cirurgia. Após 6 semanas, os animais foram submetidos ao estudo ecocardiográfico, quantificação da concentração de hidroxiprolina e da área seccional (CSA) miocitária do ventrículo esquerdo (VE). RESULTADOS: A EAo induziu aumento da espessura da parede do VE. Os animais LIS e LOS não apresentaram diferença em relação aos animais controles. Os ratos EAo e LIS apresentaram maiores diâmetros do átrio esquerdo que os ratos controles, enquanto nos animais LOS não houve diferença. Os animais com EAo apresentaram maiores valores da porcentagem de encurtamento que os controle. Esse fato não foi modificado com LIS ou LOS. A CSA dos animais do grupo EAo foi maior que a dos controle. Entretanto, o tratamento com LOS e com LIS atenuou o aumento da área induzida pela EAo. A EAo resultou em aumento na concentração de HOP, enquanto o grupo LOS não apresentou diferença em relação ao grupo controle. CONCLUSÃO: O bloqueio do sistema renina-angiotensina, com bloqueador AT1 e com IECA, pode atenuar o desenvolvimento de hipertrofia cardíaca, porém só o bloqueio dos receptores AT1 atenua a fibrose intersticial do VE.OBJECTIVE: To assess the role of the AT1 receptor blocker and the angiotensin-converting enzyme inhibitor in cardiac remodeling induced by aortic stenosis in rats. METHODS: Wistar rats were divided into the following 4 groups: 1) C - control (n=13); 2) AoS - aortic stenosis (n=11); 3) LIS - AoS treated with lisinopril, 20 mg/kg/day (n=11); and 4) LOS - AoS treated with losartan, 40 mg/kg/day (n=9). The treatments were initiated 3 days before surgery. After 6 weeks, the animals underwent echocardiographic study, and quantification of the hydroxyproline (HOP) concentration and the left ventricular (LV) myocyte cross-sectional area (CSA). RESULTS: Aortic stenosis induced an increase in left ventricular wall thickness. The LIS and LOS groups showed no difference as compared with the control group. The AoS and LIS rats had greater left atrial diameters than the control rats did, while no difference was observed in the LOS animals. The AoS animals had greater values of shortening percentage than control animals did. This fact was modified with neither LIS nor LOS. The cross-sectional area of the animals in the AoS group was greater than that in the control group. However, treatment with LOS and LIS attenuated the AoS-induced increase in area. Aortic stenosis caused an increase in HOP concentration, while the LOS group showed no difference as compared with the control group. CONCLUSION: Blockade of the renin-angiotensin system with AT1 blocker and ACEI may attenuate the development of heart hypertrophy, but only the blockade of AT1 receptors attenuates left ventricular interstitial fibrosis

Extensive impact of saturated fatty acids on metabolic and cardiovascular profile in rats with diet-induced obesity: A canonical analysis

Background: Although hypercaloric interventions are associated with nutritional, endocrine, metabolic, and cardiovascular disorders in obesity experiments, a rational distinction between the effects of excess adiposity and the individual roles of dietary macronutrients in relation to these disturbances has not previously been studied. This investigation analyzed the correlation between ingested macronutrients (including sucrose and saturated and unsaturated fatty acids) plus body adiposity and metabolic, hormonal, and cardiovascular effects in rats with diet-induced obesity. Methods: Normotensive Wistar-Kyoto rats were submitted to Control (CD; 3.2 Kcal/g) and Hypercaloric (HD; 4.6 Kcal/g) diets for 20 weeks followed by nutritional evaluation involving body weight and adiposity measurement. Metabolic and hormonal parameters included glycemia, insulin, insulin resistance, and leptin. Cardiovascular analysis included systolic blood pressure profile, echocardiography, morphometric study of myocardial morphology, and myosin heavy chain (MHC) protein expression. Canonical correlation analysis was used to evaluate the relationships between dietary macronutrients plus adiposity and metabolic, hormonal, and cardiovascular parameters. Results: Although final group body weights did not differ, HD presented higher adiposity than CD. Diet induced hyperglycemia while insulin and leptin levels remained unchanged. In a cardiovascular context, systolic blood pressure increased with time only in HD. Additionally, in vivo echocardiography revealed cardiac hypertrophy and improved systolic performance in HD compared to CD; and while cardiomyocyte size was unchanged by diet, nuclear volume and collagen interstitial fraction both increased in HD. Also HD exhibited higher relative β-MHC content and β/α-MHC ratio than their Control counterparts. Importantly, body adiposity was weakly associated with cardiovascular effects, as saturated fatty acid intake was directly associated with most cardiac remodeling measurements while unsaturated lipid consumption was inversely correlated with these effects. Conclusion: Hypercaloric diet was associated with glycemic metabolism and systolic blood pressure disorders and cardiac remodeling. These effects directly and inversely correlated with saturated and unsaturated lipid consumption, respectively. © 2013 Oliveira Junior et al.; licensee BioMed Central Ltd