Bìofìzičnij Vìsnik

11-18

Authors: О.V. Vashchenko, L.V. Budianska

Joint action of a number of pharmaceuticals has been studied in multibilayer model membranes of L-α-dipalmitoylphosphatidylcholine. Shift of the main phase transition temperature of the membrane under the pharmaceuticals introduction (∆Tm) was determined by means of differential scanning calorimetry and used as a basic factor of their membranotropic action (MA). Pairs of pharmaceuticals were selected with various character of lipophylicity and MA; cholesterol was used as the membrane compound with the well-known MA. Revelation and identification of the effects of joint action was performed by comparison of ∆Tm values under separate and joint introduction of the pharmaceuticals. Effects of joint action appear similar for hydrophobic azithromycin and hydrophilic succinylcholine in their combinations both with povidone and with cholesterol. Examination of joint action of an active pharmaceutical intgredient (API) and and an excipient allowed us to establish a certain advantage of the API’s MA in the pairs azithromycin-lactose and azithromycin-dimetylsulfoxide, and additivity of the MA in the pair amixin-hypromelose.

27-36

Authors: A. K. Gulevsky, D. V. Tretiak

The molecular-mass distribution of peptides from supernatants, obtained from the tissues of larvae Tenebrio molitor and goldfish Carassius auratus during cold acclimation, has been determined by chromatography. The results showed that peptide spectrum of the supernatants from larvae T. molitor and C. auratus varied during cold acclimation. The supernatants from non-acclimated larvae of T. molitor and deacclimated fish possessed the highest number of peptide fractions. Furthermore, the cold-acclimated larvae of T. molitor had the peptide fractions of the low molecular weight (ca. 5.4×102 ÷22.6×102 Da), and non-acclimated insects had the peptides of the high molecular weight (ca. 46.8×102÷66×102 Da). Next, the organ-specific changes of the peptide composition of the goldfish during winter deacclimation have been revealed. Specifically, the low molecular weight peptides (ca. (14.1 ± 0.3)×102 and (6.75 ± 0.25)×102 Da), have been detected in the C. auratus muscles, and both the high (ca. (67.83 ± 0.21)×102 ( ca. 64.16 ± 0.26)×102 Da) and low (ca. (34.1 ± 1.0)×102 and (14.29 ± 0.15)×102 Da) molecular weight peptides have been detected in the liver. Quantitative and qualitative changes in the peptide spectra from supernatants of the T. molitor and C. auratus during cold acclimation could be one of the mechanisms of their natural adaptation to low temperatures.

43-50

Authors: A.A. Herus, N.A. Gladkovskaya, E.G. Bereznyak, E.V. Dukhopelnikov

The effect of chlorophyllin (Chln) on the DNA-proflavine (Pf) interactions has been investigated by spectrophotometry. The absorption spectra were recorded at different DNA-to-ligand molar ratios. Decomposition of the spectra of the Chln-Pf, Pf-DNA and Chln-Pf-DNA mixtures was performed by the principal component analysis, allowing determining the concentrations of the absorbing particles in solutions. The results indicated that chlorophyllin did not interact with DNA. The Chln-Pf heteroassociation constant (K=9×104 М) was calculated using Scatchard isotherm analysis. Furthermore, Chln showed only the interceptor properties in the ternary Chln-Pf-DNA system. Next, spectrophotometric studies of binary and ternary systems were carried out under heating of the solutions from 20 to 90°C. Temperature dependences of the particle concentrations were obtained for Chln-Pf-DNA system. It appeared that Chln interceptor properties increased with the temperature. This is due to the fact that Pf-DNA binding constant decreased under heating, while Chln-Pf heteroassociation constant did not vary significantly with the temperature.

63-70

Authors: D.F. Astapovich, V.P. Berest, L.V. Batyuk, O.A. Muraveynik

The hemolytic stability of erythrocytes is studied under various pathological conditions, including ischemia and complications after myocardial infarction. A large set of parameters are used to describe hemolysis, among which the duration of stages, the rate of stage, the percentage of hemolysed cells and others. Diagnostic interpretation of such results is difficult and is of little purpose for clinicians. The characteristics of hemolysis often are the kinetic parameters. A method for analyzing the kinetics of hemolysis is proposed, which makes it possible to obtain additional information on the distribution of erythrocytes by their hemolytic resistance. The method is easily implemented and allows obtaining statistically significant results suitable for automated diagnosis. The developed methodology was applied to the analysis of acid hemolysis of healthy volunteers and patients with cardiovascular pathology. The described approach to the analysis of the process of hemolysis of erythrocytes made it possible to reveal changes in the resistance of erythrocytes to acid-induced hemolysis in people with coronary heart disease and to detect a change in the ratio of the number of erythrocytes with different life span in the circulation.