Determination of adenine nucleotides by the modified method of high-performance liquid chromatography.

Adenine nucleotides (ATP, ADP and AMP) play a central role in the regulation of metabolism and energy: they provide the energy balance of the cell, determine its redox state, act as allosteric effectors of a number of enzymes, modulate signaling and transcription factors and activate oxidation or biosynthesis substrates. A large number of methods have been developed to determine the level of ATP, ADP and AMP, but the most universal and effective method for the separation and analysis of complex mixtures is the reversed-phase high-performance liquid chromatography method (RP-HPLC). The aim of this study is to determine the optimal conditions for the qualitative separation and quantitative determination of standard solutions of ATP (1 mmol/l), ADP (0,5 mmol/l) and AMP (0,1 mmol/l) by RP-HPLC. The degree of separation of adenine nucleotides was estimated by the time of peak output in the chromatogram. To achieve the goal, the following tasks were set: assess the effect of the temperature of the analysis on the separation and change of the release time of the analytes in the chromatogram; determine the most optimal composition of the mobile phase for the separation of ATP, ADP and AMP in the chromatogram (the content of the organic solvent in the solution); to identify the effect of pH of the mobile phase on the separation of standard solutions of adenine nucleotides; set the optimal molarity of the mobile phase for the separation of ATP, ADP and AMP in the chromatogram. It was found that the temperature of the analysis does not affect the quality of peak separation, while the composition and pH of the mobile phase have a significant effect on the complete and clear separation of the studied nucleotides in the chromatogram. It was determined that the analysis temperature of 37°C and the mobile phase of 0.05 M KH2PO4 (pH 6.0) are optimal for separating the peaks of adenine nucleotides.

[Annual blood pressure dynamics and weather sensitivity in women]. / Godovaia dinamika arterial'nogo davleniia i meteochuvstvitel'nost' u zhenshchin.

AIM: To study the annual cycle of blood pressure (BP) and weather sensitivity in normotensive women aged 20-59 years. SUBJECTS AND METHODS: The same group of 25 non-smoking women who had been living in the European North of Russia (62° N, 51° E) almost since their birth and were engaged in moderate-intensity mental labor was daily examined. During a year, there were 11823 blood pressure measurements using the Korotkoff technique; heart rate was calculated by palpation. These meteorological parameters were taken at the websites: http://meteo.infospace.ru and ftp://ftp.ngdc.noaa.gov/stp/geomagnetic_data/indices/kp_ap. The statistical significance of differences in the indicators was determined using the Fisher's test and the Newman-Keuls test. The study used a correlation analysis with the calculation of the Spearman's rank correlation coefficient. RESULTS: The maximum systolic and diastolic BP values were revealed in February and January, respectively. The minimum values of systolic BP were detected in July; those of diastolic BP were in August. An individual-based analysis of sensitivity to environmental variations showed that about 88% of the women responded to atmospheric temperature; nearly 44% did to geomagnetic activity; almost 24% were sensitive to relative air humidity, and about 16% of the women were to atmospheric pressure. CONCLUSION: The dynamics of systolic and diastolic BP in the annual cycle of women depends on meteorological factors and suggests that there is a change in the priorities of its control in different periods of a year.