Few studies have investigated the hemodynamic mechanism whereby primary hyperaldosteronism causes hypertension. The traditional view holds that hyperaldosteronism initiates hypertension by amplifying salt-dependent increases in cardiac output (CO) by promoting increases in sodium retention and blood volume. Systemic vascular resistance (SVR) is said to increase only as a secondary consequence of the increased CO and blood pressure. Recently, we investigated the primary hemodynamic mechanism whereby hyperaldosteronism promotes salt sensitivity and initiation of salt-dependent hypertension. In unilaterally nephrectomized male Sprague-Dawley rats given infusions of aldosterone or vehicle, we found that aldosterone promoted salt sensitivity and initiation of salt-dependent hypertension by amplifying salt-induced increases in SVR while decreasing CO. In addition, we validated mathematical models of human integrative physiology, derived from Guyton's classic 1972 model - Quantitative Cardiovascular Physiology-2005 and HumMod-3.0.4. Neither model accurately predicted the usual changes in sodium balance, CO, and SVR that normally occur in response to clinically realistic increases in salt intake. These results demonstrate significant limitations with the hypotheses inherent in the Guyton models. Together these findings challenge the traditional view of the hemodynamic mechanisms that cause salt-sensitive hypertension in primary aldosteronism. Key words: Aldosterone, Blood pressure, Salt, Sodium, Rat.

• MeSH
• aldosteron krev   metabolismus   MeSH
• hemodynamika * účinky léků   MeSH
• hyperaldosteronismus * patofyziologie   metabolismus   MeSH
• hypertenze * patofyziologie   etiologie   MeSH
• krevní tlak účinky léků   fyziologie   MeSH
• krysa rodu Rattus MeSH
• kuchyňská sůl * škodlivé účinky   MeSH
• modely kardiovaskulární MeSH
• modely nemocí na zvířatech * MeSH
• potkani Sprague-Dawley * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aldosteron MeSH
• kuchyňská sůl * MeSH

Recently, red beetroot has attracted attention as a health-promoting functional food. Studies have shown that beetroot administration can reduce blood pressure and ameliorate parameters of glucose and lipid metabolism; however, mechanisms underlying these beneficial effects of beetroot are not yet fully understood. In the current study, we analysed the effects of beetroot on parameters of glucose and lipid metabolism in two models of metabolic syndrome: (i) transgenic spontaneously hypertensive rats expressing human C-reactive protein (SHR-CRP rats), and (ii) hereditary hypertriglyceridemic (HHTg) rats. Treatment with beetroot juice for 4 weeks was, in both models, associated with amelioration of oxidative stress, reduced circulating lipids, smaller visceral fat depots, and lower ectopic fat accumulation in the liver compared to the respective untreated controls. On the other hand, beetroot treatment had no significant effects on the sensitivity of the muscle and adipose tissue to insulin action in either model. Analyses of hepatic proteome revealed significantly deregulated proteins involved in glycerophospholipid metabolism, mTOR signalling, inflammation, and cytoskeleton rearrangement.

• Klíčová slova
• beetroot, glycerophospholipid metabolism, hereditary hypertriglyceridemic rat, lipids, mTOR signalling, proteomics, spontaneously hypertensive rat,
• Publikační typ
• časopisecké články MeSH

High-salt diets are a major cause of hypertension and cardiovascular (CV) disease. Many governments are interested in using food salt reduction programs to reduce the risk for salt-induced increases in blood pressure and CV events. It is assumed that reducing the salt concentration of processed foods will substantially reduce mean salt intake in the general population. However, contrary to expectations, reducing the sodium density of nearly all foods consumed in England by 21% had little or no effect on salt intake in the general population. This may be due to the fact that in England, as in other countries including the U.S.A., mean salt intake is already close to the lower normal physiologic limit for mean salt intake of free-living populations. Thus, mechanism-based strategies for preventing salt-induced increases in blood pressure that do not solely depend on reducing salt intake merit attention. It is now recognized that the initiation of salt-induced increases in blood pressure often involves a combination of normal increases in sodium balance, blood volume and cardiac output together with abnormal vascular resistance responses to increased salt intake. Therefore, preventing either the normal increases in sodium balance and cardiac output, or the abnormal vascular resistance responses to salt, can prevent salt-induced increases in blood pressure. Suboptimal nutrient intake is a common cause of the hemodynamic disturbances mediating salt-induced hypertension. Accordingly, efforts to identify and correct the nutrient deficiencies that promote salt sensitivity hold promise for decreasing population risk of salt-induced hypertension without requiring reductions in salt intake.

• Klíčová slova
• blood pressure, hypertension, nitrate, salt, sodium, sodium chloride,
• MeSH
• hypertenze * chemicky indukované   prevence a kontrola   MeSH
• kardiovaskulární nemoci * MeSH
• krevní tlak MeSH
• kuchyňská sůl škodlivé účinky   MeSH
• lidé MeSH
• sodík MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kuchyňská sůl MeSH
• sodík MeSH

• MeSH
• chlorid sodný MeSH
• kuchyňská sůl * MeSH
• stravovací zvyklosti * MeSH
• Úřad Spojených států pro potraviny a léky MeSH
• Publikační typ
• práce podpořená grantem MeSH
• úvodníky MeSH
• Geografické názvy
• Spojené státy americké MeSH
• Názvy látek
• chlorid sodný MeSH
• kuchyňská sůl * MeSH

On average, black individuals are widely believed to be more sensitive than white individuals to blood pressure (BP) effects of changes in salt intake. However, few studies have directly compared the BP effects of changing salt intake in black versus white individuals. In this narrative review, we analyze those studies and note that when potassium intake substantially exceeds the recently recommended US dietary goal of 87 mmol/day, black adults do not appear more sensitive than white adults to BP effects of short-term or long-term increases in salt intake (from an intake ≤50 mmol/day up to 150 mmol/day or more). However, with lower potassium intakes, racial differences in salt sensitivity are observed. Mechanistic studies suggest that racial differences in salt sensitivity are related to differences in vascular resistance responses to changes in salt intake mediated by vasodilator and vasoconstrictor pathways. With respect to cause and prevention of racial disparities in salt sensitivity, it is noteworthy that 1) on average, black individuals consume less potassium than white individuals and 2) consuming supplemental potassium bicarbonate, or potassium rich foods can prevent racial disparities in salt sensitivity. However, the new US dietary guidelines reduced the dietary potassium goal well below the amount associated with preventing racial disparities in salt sensitivity. These observations should motivate research on the impact of the new dietary potassium guidelines on racial disparities in salt sensitivity, the risks and benefits of potassium-containing salt substitutes or supplements, and methods for increasing consumption of foods rich in nutrients that protect against salt-induced hypertension.

• Klíčová slova
• hypertension, nitrate, race, salt-sensitive, sodium,
• MeSH
• běloši MeSH
• černoši MeSH
• draslík dietní * MeSH
• hypertenze patofyziologie   MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• rizikové faktory MeSH
• sodík dietní * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• draslík dietní * MeSH
• sodík dietní * MeSH

• MeSH
• chování snižující riziko * MeSH
• dieta s nízkým obsahem soli * MeSH
• hodnocení rizik MeSH
• hypertenze diagnóza   epidemiologie   patofyziologie   prevence a kontrola   MeSH
• krevní tlak * MeSH
• kuchyňská sůl škodlivé účinky   MeSH
• lidé MeSH
• ochranné faktory MeSH
• podpora zdraví MeSH
• rizikové faktory MeSH
• stravovací zvyklosti MeSH
• výživové doporučené dávky MeSH
• zdraví - znalosti, postoje, praxe MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kuchyňská sůl MeSH