Международный неврологический журнал 6 (60) 2013

Trace elements, including selenium, play a very important role in maintaining human health. Indispensability of selenium for humans is set in 1979 during the examination of patients with juvenile cardiomyopathy, which is endemic in some regions of China. Animal protein is the primary resource for obtaining food selenium, which is 66% of the total revenues of selenium from food in Western Europe. Daily recommended use rate of selenium is 55 micrograms. In many regions of the world, including Western Europe, the concentration of selenium in the soil is less than 0,5 p.p.m., which increased risk of health problems.

Number of selenium in the body of an adult is very different in different countries due to the uneven geographical distribution of selenium in the soil, and therefore its contents in the diet. The total amount of selenium in the adult body is 13 to 20,3 mg in the U.S. but is only about 6,6 mg in Germany, at 5,2 mg in Poland and from 3 to 6,1 mg in New Zealand (Zachara and others . 2001). Under conditions of normal dietary receipt largest concentration of selenium was found in the kidneys, then the liver, spleen, pancreas, heart, brain, lungs, bones and skeletal muscles. Considering the total body weight, 25-50% of selenium was found in skeletal muscles, 16% in the bones, 7-10% in blood and 4% in the kidneys (Zachara and others. 2001). If selenium is lacking in the diet and serum the brain showing the greatest priority in the accumulation of this element (Prohaska and Ganther 1976). Even with long-term selenium depletion within six generations, which led to a decrease in the concentration of selenium in the liver, skeletal muscle and blood of experimental animals to below 1% of normal, the brain of these animals contained selenium at 60% of the selenium in the brain of control animals (Behne et al., 2000). The concentration of selenium in the human body changes with age. In healthy elderly selenium levels in the blood correlated negatively with age (Berr at al., 1993), and also is observed in patients with dementia (Ceballos-Picot et al. 1996). Selenoprotein P is the major source of extracellular selenium, accounting for up to 60-70 μg / L in blood serum. Selenoprotein P is a reliable marker of selenium food deficiency. Selenoprotein P containing about 50% and 60% human serum selenium and rats respectively (Read et al. 1990; Saito and Takahashi 2002). Selenoprotein P has been identified as the most effective donor of selenium in cell culture (Saito and Takahashi 2002). This supply function of selenium may explain the life supporting function that has selenoprotein P. Was described the relationship between selenoprotein P and motor coordination in mice (Schomburg at al. 2003, Hill et al. 2003).

Level of selenium and risk of diseases.

Known and there is no doubt among researchers that reducing of the concentration of selenium in serum of the patients significantly increases their mortality rate (Bleys J et al., 2008).

In studies of scientists from the Institute of Johns Hopkins University in Baltimore (Ray A.L. et al., 2006) also was found that the greater level of selenium in blood serum causes less mortality (relative risk 0,71). Prospective study found that serum selenium levels inversely associated with risk of progression of atherosclerosis, coronary heart disease, coronary artery disease and mortality due to cardiovascular disease (Eaton C.B. et al., 2007). Meta-analysis of 16 case-control studies found a decrease in the relative risk of coronary artery disease (up to 0,43) in subjects with higher concentration of selenium in serum but not found significant reduction of risk due to use of selenium in 6 randomized trials (Flores-Mateo G. et al. 2006). In 2006, researchers at the University of New York also published data analysis of randomized clinical trials. Was not found effect of use of selenium at a dose of 200 mg daily in the prevention of cardiovascular disease in patients who at baseline did not had them (Stranges S. et al., 2006). The researchers concluded about the ineffectiveness of use of selenium for primary prevention of cardiovascular disease. These findings can be explained to some extent by other results obtained by American researchers, the authors found that increased concentration of selenium in serum was correlated with increased risk of hypertension - in the regression model the prevalence of hypertension increased with increasing selenium concentrations up to 160 μg / L (Laclaustra M. et al. 2009). The authors from Europe concluded that selenium deficiency may be a risk factor for hypertension in European men (Tim S. et al. 2007). American researchers found of the relationship between selenium levels and the level of serum lipids (Joachim Bleys at al., 2008).

Japanese scientists (Koyama H. et al., 2009) have established predictive value for the development of cerebrovascular diseases not only the general level of selenium but selenoprotein P.

Treatment of diseases of the brain with selenium.

Pre-treatment of animals with selenium and melatonin can completely protect against depletion of dopamine in the striatum induced by the action of methamphetamine (Imam et al. 2001). Parkinson's disease, which is induced by this substance in rats has been advised due to selenium dose-dependent regulation of antioxidant status and decreased loss of dopamine. Selenium may be beneficial in slowing the progression of neurodegeneration in parkinsonism (Zafar at.al. 2003).

Promising results were obtained in a recent pilot study that was conducted by Turkish scientists (Kocaogullar Y. at al., 2010), who found that the intraperitoneal use of selenium prevents occurrence of vasospasm in animals with experimental subarachnoid hemorrhage (P <0.001).

Conclusions:

1. The problem of evaluation of effect selenium on the occurrence and course of cardiovascular and cerebrovascular diseases is extremely relevant and requires further researches.

2. The use of selenium in patients with cerebrovascular disease expediently and safely.

3. Most effective in terms of preventing the development of hypertension and stroke is the use of selenium in order to maintain its concentration in serum ranging from 110μg / L to 115μg / L, it is very important to maintain the level of selenoprotein P in serum at 63,0 μg / L.