Hypertension calcium salts

The heart may be enlarged with left ventricular hypertrophy, particularly in cases which have exhibited hypertension during life. Metastatic calcification of the valves and of the myocardium may be present, explaining no doubt the cardiac murmurs which may have been detected clinically in such cases. Occasionally, medullary proliferation of large arteries and, in the smaller arteries, fragmentation of the intimal elastic lamina has been reported, in one case with impregnation with calcium salts. Local calcification of the media of the middle cerebral artery has been described. 

Renal effects of hypercalcemia include reduced glomerular filtration rate (GFR), polyuria, nephrocalcinosis, and renal stone disease. Hypercalcemia causes renal vasoconstriction which may contribute to decreased GFR. The hypercalcemia-induced polyuria results from 1) an impairment of active transport of NaCl in the loop of Henle, distal tubule and collecting duct and 2) an inhibition of vasopressin-facilitated absorption of water in the distal nephron. As a direct result of the polyuria, many side effects including polydipsia, thirst, nocturia and dehydration are common. Precipitation of calcium salts within the kidney leads to chronic inflammatory reactions (nephrocalcinosis), fibrosis, renal impairment, nephrolithiasis and urolithiasis. Further renal damage may occur indirectly from hypertension. 

Non-pharmacological life-style modifications, including salt restriction, adequate potassium, calcium and magnesium, weight loss and exercise, should be considered in older patients. These interventions constimte a feasible, effective, and safe nonpharma-cologic treatment of hypertension in older patients. 

The secondary mineralocorticoid activity of glucocorticoids can lead to salt and water retention, which can cause hypertension. Although the detailed mechanisms are as yet uncertain, glucocorticoid-induced hypertension often occurs in elderly patients and is more common in patients with total serum calcium concentrations below the reference range and/or in those with a family history of essential hypertension (SEDA-20, 368 19). 

Elevated blood pressure is usually caused by a combination of several abnormalities (multifactorial). Epidemiologic evidence points to genetic inheritance, psychological stress, and environmental and dietary factors (increased salt and decreased potassium or calcium intake) as perhaps contributing to the development of hypertension. Increase in blood pressure with aging does not occur in populations with low daily sodium intake. Patients with labile hypertension appear more likely than normal controls to have blood pressure elevations after salt loading. 

Essential hypertension is a symptom of modem society, and its treatment accounts for a sizeable portion of global prescriptions. As a result, there is a great interest in reported ethnic and racial differences reported in the literature. The use of appropriate therapy in Black patients has been best studied. As monotherapy, calcium channel blockers and diuretics appear to be most effective in Blacks, whereas P-blockers and ACE inhibitors produce smaller reductions in blood pressure (Kiowiski et al, 1985 Freis, 1986 Hall, 1990). However, this may more reflect the lower plasma renin, salt and water retention and intercellular sodium and calcium in Blacks, compared to other groups (Kiowiski et al., 1988). There are individual exceptions amongst patients and among drugs, even within these classes for example labetalol, a combined a-blockers and P-blockers, can be equally effective in both African-Americans and Caucasians and, as mentioned previously, the Chinese appear twice as sensitive to propranolol as Caucasians (Oster etal., 1987 Zhou etal., 1990). 

Drugs that dilate blood vessels by acting directly on smooth muscle cells through nonautonomic mechanisms are useful in treating many hypertensive patients. Three major mechanisms are utilized by vasodilators release of nitric oxide, opening of potassium channels (which leads to hyperpolarization), and blockade of calcium channels (Table 11-3). Compensatory responses are marked for some vasodilators (especially hydralazine and minoxidil) and include salt retention and tachycardia (Table 11-2). 

Iodine is an essential component of thyroid hormone either low or high intake may lead to thyroid disease. Currently, intake of seaweed, a low-calorie food containing sufficient calcium, potassium, iron and vegetable fibers, has been recommended for the prevention of ischemic heart diseases, cerebrovascular diseases, dys-hpidemia, diabetes mellitus, hypertension, metabofic syndrome and obesity, as well as for osteoporosis and iron-deficiency anemia (Mizukami et ai, 1993). Besides, salt has been iodized, and as a result, iodine intake has increased throughout the world (Zhao et ai, 1998). 

The derivatives of l,4-dUiydro-2,6-dimethylpyridines (1,4-DHP) are used for treatment of hypertension and regulation of blood pressure, acting as calcium channel modulators. The widely prescribed drugs are amlodipine (administered as a salt, the racemate) and felodipine (free base form). These two compounds, like most 1,4-DHPs, occur as R- and S-enantiomers because of an asymmetric substitution of ester groups (the chiral center is atom C4). Amlodipine besylate and felodipine have been studied by C CP MAS NMR and C1 NQR followed by DFT calculations. The methods did not differentiate between S- and R-enantiomers because of the symmetry of the 4-aryl ring comprising one (amlodipine) or two (felodipine) chlorine atoms oriented in a perpendicular fashion. 

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