To check the proposed hypothesis that the relative content of individual polyunsaturated fatty acids (PUFAs)--substrates and inhibitors of prostanoid synthesis--in plasma can be regarded as a ...quantitative risk factor of blood clotting, a test was conducted on free fatty acids content in blood plasma of healthy people (group 0) and patients with heart ischemia before (group 1) and after (group 2) they were treated for a month with a food additive called "Eiconol," enriched with PUFA omega 3. Different proportions of PUFAs have been calculated in all cases, accounting for the contribution of each acid to the process of primary clotting. Comparison of PUFA rations among the three groups showed significant differences of means between groups 0 and 1 and also group 1 and 2 for 6 out of 7 proposed coefficients, which disappeared after "Eiconol" treatment (comparison of groups 0 and 2). The results led to the conclusion that out of the proposed PUFA proportions, the coefficients describing the relative content of arachidonic acid in blood plasma may be the most informative for diagnosis and treatment efficiently in evaluation of heart and vascular diseases.
A scheme of interactions of Mg2+ ions and their 1 : 1 complex with PPisub (PPiMg′) with two forms of inorganic pyrophosphatase isolated from beef heart mitochondria has been deduced from the analysis ...of enzyme kinetics at pH varying from 5.6 to 8.5. The scheme implies the existence of two catalytically important metal‐binding sites on the enzyme. The two enzyme forms differ in maximal velocity and affinity for the metal activator. The pH dependence of kinetic parameters suggests that the active form of the substrate is MgP2O2−7. Ca2+ ions strongly inhibit pyrophosphatase activity and the corresponding Hill coefficient is 1.5. Phosphate and ATP are weak inhibitors of pyrophosphatase of the competitive and noncompetitive type respectively. The results show that these forms of mitochondria1 pyrophosphatase are similar to pyrophosphatases isolated from other sources.
The authors examined the ratios of blood free polyunsaturated fatty acids (PUFA), such as 20:3n6, 20:4n6, 20:5n3, and 22:6n3, which are substrates and inhibitors of synthesis of thromboxane A2 and ...prostacyclins that regulate both normal blood fluidity, and platelet adhesion and primary thrombogenesis. The object of the study was plasma from healthy subjects and 4 groups of patients with cardiovascular diseases: 1) large myocardial infarction; 2) resting and exercise-induced angina pectoris; 3) large myocardial infarction; and 4) recurrent myocardial infarction. The levels of plasma free PUFA were measured by gas chromatography. Assessment of the PUFA ratios indicated that the risk for thrombogenesis increased in large and recurrent myocardial infarctions as compared to small myocardial infarction and angina pectoris both by reducing the relative levels of 20:3n6 and, in particular, 20:5n3, substrates of synthesis of only thrombolytics and vasodilators and by more greatly inhibiting the synthesis of prostacyclins than thromboxane with elevated 22:6n3 levels.
A kinetic study of inorganic pyrophosphatase isolated from brewer's yeast was done. It was shown that all three isoenzymes have the same pH-optimum and specificity with respect to substrate and metal ...activator. Statistical treatment of the kinetic data yielded equilibrium and catalytical constants, describing enzyme interaction with the metal activator and substrate. The catalytic properties of all three isoenzymes are similar to those of the baker's yeast pyrophosphatase. The fluoride inhibition pattern for inorganic pyrophosphatase from brewer's yeast is similar to that for the baker's yeast enzyme.
A kinetic study of inorganic pyrophosphatase isolated from brewer's yeast was done. It was shown that all three isoenzymes have the same pH-optimum and specificity with respect to substrate and metal ...activator. Statistical treatment of the kinetic data yielded equilibrium and catalytical constants, describing enzyme interaction with the metal activator and substrate. The catalytic properties of all three isoenzymes are similar to those of the baker's yeast pyrophosphatase. The fluoride inhibition pattern for inorganic pyrophosphatase from brewer's yeast is similar to that for the baker's yeast enzyme.
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