Dietary fat and hypertension: a novel approach through the proteolytic regulatory enzymes of the renin-angiotensin-system.
ABSTRACT The role of individual fatty acids in blood pressure regulation is unclear, although it is known that the modifications in the levels of fatty acids in the diet are able to change the entire profile of fatty acids as well as cholesterol levels in cellular membranes. These chemical changes are accompanied by changes in the physiological state of the cellular membranes and have suggested an influence on cellular metabolism and of course, on the regulatory processes. Local and circulating renin-angiotensin-systems (RAS) are examples of systems that may be involved in the pathogenesis of hypertension. Angiotensin II (AngII) has been considered as the main effector peptide of the RAS, but other peptides derived from the metabolism of AngII, as angiotensin III (AngIII) and angiotensin IV (AngIV) have shown to play significant roles. This review will briefly summarize what is known about the effects of fatty acids, cholesterol and other related compounds on the activity of the aminopeptidases involved in the metabolism of Ang II and AngIII. We conclude that these enzyme activities may be modified in different way, and therefore, possible modifications in RAS and in cardiovascular illness may be possible too.
Full-textDOI: · Available from: José Manuel Martínez-Martos, Jan 14, 2015
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ABSTRACT: Hypothesis. Renin-angiotensin system (RAS) has been considered not only as a regulator of systemic volume and electrolyte balance but also has been recently involved in various pathological processes such as cancer. In the etiology of breast cancer, dietary factors have been analyzed and especially the influence of dietary fat has been studied, but the underlying mechanisms remain unclear. In this study, we analyzed RAS-regulating enzymes in serum of rats with N-methyl nitrosourea (NMU)-induced breast cancer fed with different diets. Study Design. Four groups of rats were injected intraperitoneally with 3 doses of 50 mg/kg body weight of NMU at different days after birth and were fed with an AIN-93 commercial diet or AIN-93 diets with 4% fat constituted respectively by extra virgin olive oil, refined sunflower oil, and refined sunflower oil enriched to 50% with oleic acid. Method. After sacrifice, blood and tumor samples were collected by spectrophotometric determinations of RAS-regulating enzymes in plasma and histopathology studies. Results. We show that the type of dietary fat does not influence latency period, incidence of animals with tumors, incidence of mortality, or tumor yield per rat. However, changes were observed in tumor volume and the histopathology. The type of dietary fat also differently modified the enzymes involved in RAS regulation. Conclusions. It might suggest that one of the mechanisms by which dietary fat affects breast cancer is the modification of the RAS system, which may be consider as a new target for integrative therapies. © The Author(s) 2014.Integrative Cancer Therapies 12/2014; 14(2). DOI:10.1177/1534735414562956 · 2.01 Impact Factor
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ABSTRACT: Hypertension is the major risk factor for coronary heart disease, stroke, and renal disease. Also, it is probably the most important risk factor for peripheral vascular disease and vascular dementia. Although hypertension occurs in both men and women, gender differences have been observed. However, whether sex hormones are responsible for the observed gender-associated differences in arterial blood pressure, and which is their mechanism of action, remains unclear. Local and circulating renin-angiotensin systems (RAS) are examples of systems that may be involved in the pathogenesis of hypertension. Classically, angiotensin II (Ang II) has been considered as the effector peptide of the RAS, but Ang II is not the only active peptide. Several of its degradation products, including angiotensin III (Ang III) and angiotensin IV (Ang IV) also possess biological functions. These peptides are formed via the activity of several aminopeptidases. This review will briefly summarize what is known about gender differences in RAS-regulating aminopeptidase activities, their relationship with sex hormones, and their potential role in controlling blood pressure acting through local and circulating RAS.Heart Failure Reviews 10/2008; 13(3):355-65. DOI:10.1007/s10741-008-9082-1 · 3.99 Impact Factor