The objective of this study was to evaluate the effect of diet and 677 C®T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene on plasma homocyst(e)ine concentrations in an adolescent population (113 males, age: 14.2±2.4 years; 202 females, age: 14.9±2.1 years) from a region characterized by high cardiovascular mortality. Homocyst(e)ine levels did not differ between males and females (9.4±3.5 and 8.9±3.1 mmol/l, respectively). The homozygosity for the 677 C®T MTHFR mutation was found in 4.6 % of subjects. No differences in homocyst(e)ine levels were found between MTHFR genotypes. Analysis of the diet composition which was performed on a 24-hour daily recall basis and a food frequency questionnaire showed a low daily intake of vitamin B6 (males: 1.13 mg/66 % RDA; females: 0.92 mg/61 % RDA). Daily folic acid intake was 0.21 g/105 % RDA in males and 0.23 g/115 % RDA in females. The results of our study show that the high homocyst(e)ine levels in the adolescent population were not affected by the 677 C®T MTHFR mutation. We conclude that an insufficient dietary intake of vitamin B6 and folic acid is responsible for this finding. This is in accord with the recommendation that the dietary allowances for folate should be reset to the originally prescribed levels of 0.4 g/day which should be sufficient to control the homocysteine levels., K. Rašlová, A. Bederová, J. Gašparovič, P. Blažíček, B. Smolková., and Obsahuje bibliografii
a1_The decreased oxidizability of plasma lipoproteins is related to the increased vitamin E intake and its association with a relatively lower incidence of coronary heart disease has been proposed. We investigated the effect of the in vivo vitamin E supplementation on the oxidizability of serum lipids in patients with ischemic heart disease and a moderate hypercholesterolemia. Thirty-two patients (16 males and 16 postmenopausal women) participated in this placebo-controlled, randomized trial. They were treated with 400 mg vitamin E/day for 6 weeks. The copper-induced serum lipid oxidizability ex vivo was assessed by measuring conjugated diene formation at 245 nm. We also measured vitamin E, malondialdehyde (MDA) and uric acid concentrations in the plasma. Because of observed significant differences in parameters of serum lipid oxidizability (lag time and maximal rate of oxidation), plasma a-tocopherol and MDA levels between male patients and postmenopausal women supplemented with vitamin E, the results were compared between both genders. Six weeks of vitamin E supplementation significantly increased plasma vitamin E levels (by 87 %) in male patients but in postmenopausal women only by 34 %. Concomitantly with increased plasma levels of vitamin E the decrease in plasma MDA levels was observed in male patients (decrease by 20 %; p=0.008), but in postmenopausal women the decrease did not attain statistical significance. Plasma uric acid levels were not apparently changed in placebo or vitamin E supplemented groups of patients. The changes in ex vivo serum lipid oxidizability after vitamin E, supplementation have shown a significantly prolonged lag time (by 11 %; p=0.048) and lowered rate of lipid oxidation (by 21 %; p=0.004) in male patients in comparison with postmenopausal women., a2_Linear regression analysis revealed a significant correlation between plasma vitamin E levels and the lag time (r=0.77; p=0.03) and the maximal rate of serum lipid oxidation (r=-0.70; p=0.05) in male patients. However, in postmenopausal women the correlations were not significant. We conclude that 400 mg vitamin E/day supplementation in patients with ischemic heart disease and a moderate hypercholesterolemia influenced favorably ex vivo serum lipid oxidation of male patients when compared with postmenopausal women. The observed differences between both genders could be useful in the selection of the effective vitamin E doses in the prevention of coronary heart disease., A. Nagyová, V. Mongiellová, Z. Krivošíková, P. Blažíček, V. Spustová, M. Gajdoš, R. Dzúrik., and Obsahuje bibliografii
The aim of our study was to characterize resistance to ischemia/reperfusion (I/R) injury in Langendorff-perfused rat hearts and effectivity of ischemic preconditioning (PC) under condition of simulated acute hyperglycemia (SAHG) by perfusion of the hearts with Krebs-Henseleit (KH) solution with elevated glucose concentration (22 mmol/l). I/R injury was induced by 30- min coronary occlusion followed by 120-min reperfusion and PC by two cycles of 5-min occlusion/5-min reperfusion, prior to I/R. The severity of I/R injury was characterized by determination of the size of infarction (IS, expressed in % of area at risk size) and the amount of heart-type fatty acid binding protein (h-FABP, a marker of cell injury) released from the hearts to the effluent. Significantly smaller IS (8.8±1 %) and lower total amount of released h-FABP (1808±660 pmol) in PC group compared with IS 17.1±1.2 % (p<0.01) and amount of h-FABP (8803±2415 pmol, p<0.05) in the non-PC control hearts perfused with standard KH solution (glucose 11 mmol/l) confirmed protective effects of PC. In contrast, in SAHG groups, PC enhanced IS (21.4±2.2 vs. 14.3±1.3 %, p<0.05) and increased total amount of h-FABP (5541±229 vs. 3458±283 pmol, p<0.05) compared with respective non-PC controls. Results suggest that PC has negative effect on resistance of the hearts to I/R injury under conditions of elevated glucose in vitro., M. Zálešák, P. Blažíček, D. Pancza, V. Ledvényiová, M. Barteková, M. Nemčeková, S. Čarnická, A. Ziegelhöffer, T. Ravingerová., and Obsahuje bibliografii