The hERG subtype potassium channel (Kv11.1) is one of the most important and one of the most studied biological targets for the creation of cardioprotective agents. A large number of both blockers and activators/modulators of the hERG channel have been described with biaromatic structure. Substances with an hERG-mechanism are used primarily for the effective regulation of the action potential duration in the heart tissues and for the control of the QT interval on the electrocardiogram. Among the hERG blockers, the most well-known drug is dofetilide, which is used to maintain sinus rhythm in atrial fibrillation. The review presents all currently known ligands of the hERG channel with a biaromatic structure and the data on their biological properties.

The aim of the work is to study the effect of the anxiolytic fabomotizole (15 mg/kg, i.v.) on atrial depolarization in the acute phase of myocardial infarction using the method of synchronous multichannel cardioelectrochronotopography. Synchronous multichannel cardioelectrochronotopography was used to study the sequence of depolarization of the atrial epicardium in outbred rats during the acute phase of myocardial infarction caused by ligation of the anterior branch of the left coronary artery with simultaneous administration of the σ1-receptor agonist fabomotizole. Significant differences in the temporal characteristics of atrial depolarization in the acute phase of myocardial infarction were revealed in control animals and animals treated with fabomotizol. In rats against the background of fabomotizol, changes in the time of the onset of epicardial depolarization, the transition of the excitation wave from the right to the left atrium, and the end of depolarization, compared with the initial state, occur by the 5th minute after the ligation of the coronary vessel; in the process of further development of acute myocardial infarction, changes in time parameters are not observed .In animals of the control group, changes in the time parameters of atrial depolarization after coronary vessel ligation develop by 10 minutes after ligation and continue to change as acute myocardial infarction develops. Anxiolytic fabomotizol in the most acute phase of myocardial infarction changes the time parameters of atrial depolarization, preventing the development of atrial fibrillation.

A validated method for the quantitative determination of venlafaxine, O-desmethylvenlafaxine in human plasma by tandem liquid chromatographymass spectrometry (HPLC/MS/MS) has been proposed. Sample preparation was carried out by liquid-phase extraction with support (SLE, from «supported liquid extraction») using HyperSEP cartridges and washing with 3-methylbutyl ether. The measure of the target analytes was carried on a triple quadrupole mass spectrometer under multiple-reaction monitoring (+MRM) mode with the electrospray ionization. The calibration curves were linear with regression coefficient r² > 0.999. The method validation was showed high sensitivity, specificity, accuracy and reproducibility, as well as stability of analytes after freeze/thaw cycles and storage at –20 °C. The method is developed for using in therapeutic drug monitoring.

Relevance. Evaluation of the effect of drugs on neurotransmitter processes is an important component of pharmacodynamic studies. The quantitative determination of monoamine neurotransmitters in the brain structures of laboratory animals is an urgent task of pharmacology and physiology.

Purpose of the study. Development of a method for the quantitative determination of serotonin, dopamine, norepinephrine, histamine and epinephrine in rat brain homogenates using HPLC-MS/MS.

Methods. The isolation of neurotransmitters from the brain of rats was carried out by homogenizing the biomaterial with acetonitrile and hydrochloric acid. The extraction was purified by liquid-liquid extraction with chloroform and isopropanol. Monoamines were detected using an AB Sciex QTrap 3200MD mass spectrometer, chromatography was performed using an Agilent Technologies 1260 Infinity II HPLC. Methanol and deionized water were used as eluent.

Results. Sample preparation consisted of centrifugation of the resulting homogenate, drying of the supernatant in a stream of nitrogen, dissolution of the precipitate in the mobile phase, and purification of the solution using a mixture of chloroform and isopropanol. An Agilent InfinityLab Poroshell 120 EC-C18 4.6×100 mm, 2.7 μm analytical column was used to separate monoamine neurotransmitters. The total time of the chromatographic analysis was 12 minutes, the retention time of norepinephrine, epinephrine, dopamine, serotonin, histamine was 2.8; 3.2; 5.4; 7.9; and 2.2 minutes, respectively. The analytical range of the technique was 25.0–5000.0 ng/g for epinephrine, histamine, and dopamine; 5.0–5000.0 ng/g for serotonin and 50.0–5000.0 for norepinephrine. To test the technique, we analyzed monoamine neurotransmitters in the striatum of intact Wistar rats.

Conclusion. The developed bioanalytical HPLC-MS/MS method for the quantitative determination of monoamine neurotransmitters in the rat brain fully complies with the validation requirements. The metrological characteristics of the technique make it possible to estimate the content of norepinephrine, epinephrine, dopamine, serotonin, and histamine in the brain structures of rats with high accuracy.

Relevance. Diabetes mellitus is a widespread, socially significant disease. In this regard, it is important to obtain an experimental model that precedes subsequent experiments on pharmacological screening and/or study of the mechanism of action of antidiabetic agents.

The aim of this work was a comparative assessment of the manifestation of hyperglycemia, DNA damage, and morphology of internal organs in BALB/c mice in the modeling of diabetes mellitus by a single administration of streptozotocin at a dose of 200 mg/kg and its fractional, five-day administration at a rate of 40 mg/kg per day.

Methods. Streptozotocin was used as an inducer of diabetes. The drug was administered to mice once at a dose of 200 mg/kg or 5 times daily at a dose of 40 mg/kg. We monitored hyperglycemia, DNA damage in the cells of the brain, liver, kidneys, pancreas and testes, and also assessed the microscopic picture of individual internal organs, including the pancreas.

Results. In both variants of the experiment, the reproduction of pathognomonic signs of diabetes mellitus is traced. They are somewhat more clearly seen in the variant of the experiment with a fractional, five-day administration of streptozotocin in single doses of 40 mg/kg.

The interaction of the neurotrophin BDNF dipeptide mimetic, compound GSB-106, with the tyrosine kinase TrkB receptor specific for the fullsized neurotrophin was studied using surface plasmon resonance. The significant decrease in the binding of BDNF to TrkB, which was preincubated with GSB-106, was shown. The obtained data indicate the interaction of GSB-106 with the TrkB receptor.

To assess the pharmacological safety of the dipeptide mimetic of the 2nd loop of BDNF (compound GTS-201) when co-administered with ethanol, its effect on the alteration in motor activity induced by ethanol during acute and subchronic administration in mice C57Bl/6 and DBA/2 was studied. It was found that GTS-201 at a dose of 5.0 mg / kg, i.p., without affecting spontaneous motor activity per se, after a preliminary acute administration prevented the development of a sedative reaction caused by ethanol (2.0 g/ kg, i.p.) in C57Bl/6 mice. After subchronic administration, GTS-201 is devoid of psychostimulant effect and impact on the formation of ethanol-induced behavioral sensitization in DBA/2 mice. The data obtained indicate the absence of a psychostimulant component and synergism in the pharmacological profile of GTS-201 when used with ethanol at low dose.

Introduction. Telmisartan is widely used in clinical practice during hypertension treatment. It is a specific angiotensin II receptor antagonist (type AT1), effective at oral intake, A bioequivalence study of Telzap^® and Mikardis^® was conducted with 60 volunteers.

Aim. The purpose of the bioequivalence trial was a comparative study of the pharmacokinetics and evidence of the bioequivalence of Mikardis^® (telmisartan, tablets 80 mg, Boehringer Ingelheim International GmbH, Germany) and Telzap^® (telmisartan, tablets 80 mg, Zentiva KS company, Czech Republic) in healthy volunteers after a single administration under fasting.

Materials and methods. To prove bioequivalence, an open label, comparative, randomized, crossover four-period replicate single-center clinical trial was conducted. The concentrations of telmisartan in plasma samples were determined by a validated HPLC-MS/MS method. A pharmacokinetic and statistical analysis was performed and confidence intervals for the pharmacokinetic parameters C_max and AUC_0-72 were calculated.

Results and discussion. It can be concluded that the studied formulations are bioequivalent in terms of pharmacokinetic parameters of test and reference drug. All 90 % confidence intervals of were within the bioequivalence range of 80–125 % for AUC_0-72 and 73,07–136,85 % for C_max.

Conclusion. Thus, according to the criteria used in the study, the formulations are proved to be bioequivalent.

Introduction. A fixed dose combination of telmisartan and hydrochlorothiazide is indicated for treatment of in the treatment of arterial hypertension. The combination of these substances causes an additive effect that helps to reduce blood pressure. A bioequivalence study of Telzap^® Plus compared with MikardisPlus^® was conducted with 63 volunteers.

Aim. The purpose of the bioequivalence trial was a comparative study of the pharmacokinetics and evidence of the bioequivalence of the fixed dose combination drug product Telzap^® Plus (tablets 80 mg + 12,5 mg, Zentiva KS company, Czech Republic) compared with drug products MikardisPlus^® (telmisartan+hydrochlorothiazide, tablets 80 mg + 12,5 mg, Boehringer Ingelheim Pharma GmbH & Co. KG, Germany) in healthy volunteers after a single administration under fasting.

Materials and methods. To prove bioequivalence, an open label, comparative, randomized, crossover fourperiod replicate single-center clinical trial was conducted. The concentrations of hydrochlorothiazide and telmisartan in plasma samples were determined with a validated HPLC-MS/MS method. A pharmacokinetic and statistical analysis was performed and confidence intervals for the pharmacokinetic parameters C_max and AUC_0-72 were calculated.

Results and discussion. It can be concluded that the studied formulations are bioequivalent in terms of pharmacokinetic parameters of hydrochlorothiazide and telmisartan. All 90 % confidence intervals for the estimated pharmacokinetic parameters of hydrochlorothiazide were in the range of 80–125 %, 90 % confidence intervals for telmisartan were within the bioequivalence range of 80–125 % for AUC_0-72, and 79,30–126,11 % for C_max.

Conclusion. Thus, according to the criteria used in the study, the formulations are proved to be bioequivalent.