Abnormalities of Ion Transport in Hypercholesterolemia and Hypertriglyceridemia: A Link with Essential Hypertension?
Antonio Coca, Ricardo P. Garay in Ionic Transport in Hypertension: New Perspectives, 2019
As the importance of sodium became appreciated for its possible involvement in blood pressure regulation and the development of hypertension, mechanisms of moving sodium and other associated ions in and out of cells were intensively studied. Na-K ouabain-sensitive transport was recognized as the major sodium transporter to maintain proper ionic gradients. Na-K cotransport was later recognized as another transport system that could either remove or increase cellular sodium content depending on the existing gradients that were present. Significant differences were found between hyper- and normotensive patients. In 1980, the first report of a Na-Na transport system measured by using Li for Na-Li countertransport was published showing abnormalities of this system in hypertensive patients. It was later suggested that this system may represent a Na-H antiport system known to be an important sodium transport mechanism that existed in the renal proximal tubules. These transport systems have been described in other chapters and this chapter focuses on the possible modification of the expression of these systems in patients with lipid or lipoprotein abnormalities. Evidence is weighed as to whether dysli-pidemia may be an underlying cause of or an intermediate link between ion transport abnormalities and the development of hypertension. Insulin resistance resulting in hyperinsulinemia has been shown to be closely related to dyslipidemia and hypertension and may have important effects on ion transport. Resistance to cellular membrane uptake of glucose may also be affected by cell membrane lipid or phospholipid content, which affects membrane fluidity and may alter the binding capacity or activity of ion transport proteins.
Sodium
Linda M. Castell, Samantha J. Stear (Nottingham), Louise M. Burke in Nutritional Supplements in Sport, Exercise and Health, 2015
Sodium is a cation with an atomic weight of 23. It is an essential nutrient and although it is commonly found in the diet as sodium chloride (NaCl), many other anions are partnered with it in foods, food ingredients and supplements. An example of these is the use of sodium bicarbonate as a buffer, as described elsewhere in this publication (see section on sodium bicarbonate). Typical daily sodium intake varies greatly between individuals depending on the composition and quantity of food intake, with processed foods (where salt is used as a preservative and flavour enhancer) being a major contributor to intake. Most major health organisations recommend that daily sodium intake for adults should not exceed about 1,500–2,300mg (4–6g/day of salt) because of the association between high intakes and hypertension (EFSA, 2005), although this is more pertinent for those individuals that are ‘salt sensitive’. High blood pressure is strongly associated with cardiovascular disease and may also be linked to other health problems, such as renal disease. Average daily salt intake for adults in Europe is about 8–12g/day for men and 6–10g/day for women, but this varies between countries (EFSA, 2005). Sodium is the main electrolyte in the extracellular fluid, present in concentrations averaging around 140mmol/l, and it can be lost in significant amounts during sweating, with normal sweat sodium concentration in the range of 15–80mmol/l. Therefore, when thermally induced sweating occurs, the typical response is a loss of water in excess of sodium, relative to the extracellular fluid concentration, which causes an increase in the extracellular sodium concentration. (See section on electrolytes elsewhere in this book.)Plasma sodium concentration is a key determinant of plasma osmolality, and therefore of plasma volume, and thus plays a key role in the regulation of body water balance.
Nutrition
Barbara Smith, Linda Field in Nursing Care, 2019
Minerals are inorganic compounds that exist in the body as free ions . A good example is sodium chloride. When sodium chloride enters the body and dissolves in water, it dissociates (splits) into its constituent ions:The plus and minus signs show that the sodium ion (Na+) carries a positive charge and the chloride ion (Cl-) carries a negative charge. There are two categories of minerals: macrominerals and microminerals. Macrominerals are required daily in amounts over 100 mg and include calcium, phosphorus, sodium, potassium, magnesium, chloride and sulphur. Microminerals are needed in daily amounts of less than 100 mg and include iron, zinc, manganese, iodine, fluoride, copper, cobalt, chromium and selenium (Kozier et al., 2004, 2014).
Biodielectric phenomenon for actively differentiating malignant and normal cells: An overview
Published in Electromagnetic Biology and Medicine, 2020
Active research is invested in early diagnosis of malignant cells in order to allow scope for effective treatment. The electrical impedance measurements and the modeling techniques used to perform the calculation for dielectric permittivity, conductivity and relaxation frequency aids in the differentiation of malignant and healthy cells. The literature showed a general trend in data with malignant cells having higher electrical conductivity and lower dielectric permittivity than its surrounding healthier cells. However, the relaxation frequency that correlates with the dielectric loss factor was found twice in magnitude for cancer cells than healthy cells. The water content of a cancer cell is found higher and hence correlates with the shift in the relaxation time. The intracellular sodium ion concentration is also realized to be higher for malignant cells than normal cells and accounts for the depolarized transmembrane potential. Hence, this paper forms the framework for future technological innovation that can be taken into account to actively diagnose cancer cell.
The Effect of pH and Ionic Strength on the Release of Quinine Adsorbed on to an Insoluble Sodium Polyphosphate
Published in Drug Development and Industrial Pharmacy, 1996
Ross A. Kennedy, Peter J. Stewart
The preparation and evaluation of a potential prolonged-release drug delivery system with the model drug quinine HCl adsorbed onto an insoluble sodium polyphosphate (Maddrell's phosphate type II) is described. The delivery system was prepared by equilibration of the drug with a suspension of the polyphosphate and then compressing the dried adsorbed complex into disks. It was shown that the extraction of the drug from the loose powder was enhanced by increasing the sodium ion concentration and by reducing the pH. The effect of sodium ion concentration upon release of the drug from compressed dish depended upon the pH of the dissolution fluid. At low pH, which slowly dissolved the disks, the zero-order release of quinine was reduced as the ionic strength of the dissolution medium was increased. At near-neutral pH, the release of quinine was first-order at sodium concentrations greater than 0.025 M and was zero-order at sodium concentrations lower than 0.025 M. The release was promoted by an increase in the ionic strength.
Key clinical features a general internist needs to know about Brugada syndrome: a case-based discussion
Published in Journal of Community Hospital Internal Medicine Perspectives, 2015
WuQiang Fan, Laura Chachula, Yin Wu, Koroush Khalighi
IntroductionBrugada syndrome (BrS) is an autosomal dominant genetic disorder involving the abnormal function of cardiac voltage-gated sodium ion channels. Sodium channel loss of function can lead to early repolarization and loss of the Phase 2 action potential dome in cardiomyocytes. In BrS, this sodium channelopathy occurs in some, but not all, epicardial cells thus creating 1) juxtaposition of depolarized and repolarized cells in the epicardium and 2) a transmural voltage gradient. Together, these conditions can set up a Phase 2 reentry and resultant malignant cardiac arrhythmia. Of the three types of electrocardiogram (EKG) changes seen in BrS, only the Type 1 EKG is considered diagnostic. In a controlled setting, sodium channel blockers and Brugada EKG leads may be used to unmask this diagnostic EKG finding. Fever and certain medications that interfere with the sodium channel can also trigger these changes, which can be catastrophic. Case reportA 26-year-old white male presented with febrile upper respiratory infection symptoms and had an EKG change, which was initially misinterpreted as an ST elevated myocardial infarction due to ST-T segment elevation in leads V1 and V2. The patient reported past recurrent syncopal episodes leading to a recent suspected diagnosis of BrS. A later episode of febrile illness, triggering a Type 1 EKG pattern, led to a subsequent hospital admission for continuous cardiac monitoring. On that occasion, he was placed on a wearable external defibrillator pending placement of implantable cardioverter defibrillator (ICD) device. ConclusionDue to the gravity of symptoms that can manifest in the BrS patient, it is important to recognize and treat this condition promptly and effectively. BrS patients require admission for continuous cardiac monitoring when febrile and certain medications interfering with the sodium channel should be avoided in this population. Although medications may be used as one treatment modality, definitive therapy is placement of an ICD device.
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