Aim. A comparative study of the pharmacokinetics and safety of the investigational drug Duonica®, enteric-soluble, film-coated tablets, 10 mg + 10 mg (Valenta Pharm JSC, Russia) and the reference drug Diclectin®, delayed-release tablets, 10 mg + 10 mg (Duchesnay Inc, Canada) was conducted as part of the bioequivalence study in healthy volunteers under fed conditions.

Material and methods. An open-label randomized crossover two-period bioequivalence study was conducted with 28 Caucasian female volunteers. The study participants were randomly divided into two groups of 14 people depending on the order of drug administration during Periods 1 and 2. Participants randomized to the first group received 2 tablets of Diclectin® during Period 1 and 2 tablets of Duonica® during Period 2. Volunteers from the second group took the study drugs in the reverse order. During each study Period, the drugs were administered after a high-calorie breakfast. The analytes studied were doxylamine and pyridoxal-5-phosphate (an active metabolite of pyridoxine). Methods were developed and validated using high-performance liquid chromatography with a triple quadrupole tandem mass spectrometric detector (HPLC-MS/MS) to quantify the analytes. Pharmacokinetic parameters were calculated from the obtained concentration values and statistical analysis was performed. To confirm bioequivalence, 90 % confidence intervals (CI) for the pharmacokinetic parameters AUC and Cmax of the studied analytes were calculated. The safety of the investigational drugs was assessed based on the frequency, severity and type of adverse events.

Results. The 90 % CI values for the ratio of Cmax and AUC(0-t) values for doxylamine were 94.08–113.71 % and 90.63–102.50 %, and for pyridoxal-5-phosphate were 97.34–123.47 % and 90.30–111.03 %, respectively. The obtained CI values were within the limits set by the regulatory requirements and the study protocol (80.00–125.00 %), which allowed us to confirm the bioequivalence of the studied drugs for both components. No adverse events were reported during the study.

Conclusion. The study investigated the pharmacokinetics of drugs containing a fixed combination of doxylamine and pyridoxine under fed conditions. The results obtained confirmed the bioequivalence of the drug Duonica® to the reference drug Diclectin®. Both drugs were well tolerated and no differences in the safety profile of the investigational drugs were observed.

Purpose of the study. Search for an optimal approach to developing a translational model of endothelial dysfunction (ED).

Materials and methods. The experiments were carried out on 58 white male rats, which were randomized into 8 groups: 1st (n = 6) — control for L-methionine (in vitro experiments); 2nd (n = 6) — L-methionine (in vitro experiments); 3rd (n = 6) — control for L-NAME (in vitro experiments); 4th (n = 6) — L-NAME (in vitro experiments); 5th (n = 10) — control for L-methionine (in vivo experiments); 6th (n = 7) — L-methionine (in vivo experiments); 7-a (n = 10) — control for L-NAME (in vivo experiments); 8th (n = 7) — L-NAME (in vivo experiments). In groups 2 and 6, animals were intragastrically administered L-methionine (3 g/kg/day for 7 days), and rats in groups 4 and 8 were administered i.p. with L-NAME (0.025 g/kg/day within 7 days). Control animals received an equivalent volume of solvent. In in vitro experiments, a four-channel myograph (Danish Myo Technology) was used to record the tonic activity of the aortic rings. The contraction strength of the aortic rings caused by norepinephrine (10−7 M) and carbachol (10−5 M) was recorded in isometric mode. In in vivo experiments on anesthetized rats (urethane 1300 mg/kg i.p.), blood microcirculation in the myocardium and skeletal muscle was recorded using laser Doppler flowmetry using a computerized laser analyzer "LAZMA-D" (manufactured by NPP "Lazma", Russia). When assessing microblood flow, the perfusion index (M) was calculated in perfusion units (perf.u.).

Results. In vitro experiments have shown that under conditions of hyperhomocysteinemia caused by L-methionine, the vascular response to norepinephrine remains practically unchanged. At the same time, the vasodilating response to carbachol (10−5 M) statistically significantly decreased by 57 % (p = 0.005). In animals treated with L-NAME, not only did the response to carbochol decrease by 55 % (p = 0.009), but also the vasoconstrictor response to norepinephrine increased by 48 % (p = 0.003). Under conditions of ED caused by both hyperhomocysteinemia and L-NAME, blood microcirculation in the myocardium and skeletal muscle is significantly reduced. It has also been shown that in the conditions of the L-NAME-induced ED model, in contrast to the L-methionine-induced ED model, there is no drop in rat body weight and practically no mortality.

Conclusion. Thus, ED induced by both hyperhomocysteinemia and L-NAME blockade of endothelial nitric oxide synthase is accompanied by similar changes in blood microcirculation in the myocardium and skeletal muscle. However, taking into account the results of in vitro experiments, we can conclude that the model of ED induced by L-NAME seems more promising, under which, in contrast to ED induced by L-methionine, the vasodilatory response of the vessel to carbachol is not only suppressed, but also the vasoconstrictor reaction to norepinephrine is activated.

Relevance. Drug pollution of the environment is a global environmental problem of our time. Increased consumption of medicines directly affects the level of pollution of various ecosystems, including water resources. The insufficient efficiency of existing methods for treating wastewater from drugs leads to drug pollution of water bodies and requires studying the effect of ultra-low doses of drugs on the human body and animals. A non-steroidal antiinflammatory drug, diclofenac, was detected in surface water samples in Kazan at a concentration of 1×10−9 M.

The purpose of this study is to study the presence of specific pharmacological effects of diclofenac detected in water samples in ultra-low doses in experimental models of pathological processes.

Methods. The experiment used 21 male white laboratory mice, which were divided into three groups (each with 7 mice). For 4 days, mice were intragastrically injected with distilled water (control group), diclofenac solution 1×10−6 M (experimental group No. 1), diclofenac solution 1×10−9 M (experimental group No. 2). On the fifth day of the experiment, inflammation was induced by injecting carrageenan lambda (1 %, Sigma) subplantarly into the right hind paw in a volume of 0.05 ml. The amount of edema was determined using an IITC Life Science plethysmometer (USA).

The results of an experimental study of the specific pharmacological activity of diclofenac showed that diclofenac in ultra-low doses of 0.32×10−3 mg per 100.0 g of weight is able to reduce the severity of acute inflammation caused by subplantar injection of carrageenan and to cause NSAID-associated gastropathy in mice.

Conclusion. The obtained data likely indicate a potential risk of adverse effects from drug contamination of the environment with diclofenac, even in ultra-low concentrations.

Purpose of the study. Studying the features of microcirculation, functional state and anatomy of the heart using the “Holiday Heart” syndrome model in rats we developed.

Materials and methods. Experiments were carried out on white outbred male rats. The “Holiday Heart” syndrome was modeled as follows: animals received a 10 % aqueous ethanol solution as the only source of fluid for the first 10 days, then tap water for 10 days, and again a 10 % aqueous ethanol solution for the next 10 days. One day after the end of the repeated intake of alcohol, the animals were taken into the experiment. Animals that received free access to tap water served as control. Some rats in the experimental group (n = 10) had an echocardiogram recorded before the start of the experiment, and on the 31st day of the experiment, after which the level of microcirculation of blood and lymph in the brain and heart was measured using laser Doppler flowmetry. In the remaining animals (n = 10), microcirculation of blood and lymph in the brain and heart was assessed on the 3rd day of alcohol deprivation.

Results. Analysis of the obtained data showed that in the conditions of the “Holiday Heart” syndrome model, significant changes occur in the anatomy, functional activity and geometry of the heart: there is a significant thinning of the anterior wall of the left ventricle heart (LV), an increase in systolic and diastolic volumes and sizes of the LV and a significant (p = 0.0018) decrease in its inotropic function. These changes occur against the background of a significant (p = 0.0081) decrease in the level of blood microcirculation in the myocardium, however, on the 3rd day of deprivation, blood flow in the microvessels of the heart increases statistically significantly (p = 0.0285).

Conclusion. In model experiments reproducing the “Holiday Heart” syndrome, it was shown for the first time that ethanol causes significant changes in the microcirculation, anatomy, functional activity and geometry of the left ventricle of the heart, which, apparently, can play a key role in the formation of myocardial electrical instability pathognomonic for this syndrome.

Relevance. The complexity of diagnosing and treating autism spectrum disorders (ASD) is attributed to their unknown etiology and pathophysiology. The investigation of ASD models induced by sodium valproate (VPA) holds significant importance in the development of effective pharmacological interventions for this disorder.

Objective. The aim of the study was to assess the impact of prenatal and postnatal exposure to VPA on the development of autism-like behavior in Wistar rats for further selection of appropriate therapeutic interventions.

Methods. Offspring of Wistar rats were exposed to VPA on the 12.5th day of prenatal development or postnatally on the 14th day. Evaluation included assessment of social behavior, anxiety, working memory, species-typical defensive behavior, exploratory, and locomotor activity.

Results. Prenatal VPA exposure led to reduced social interaction, increased anxiety, disruption of species-typical defensive behavior, and decreased locomotor activity in male rats. Female rats prenatally exposed to VPA exhibited social deficits, increased anxiety, hypolocomotion, and cognitive impairments, albeit without displaying aversive odor preference. Postnatal VPA exposure in male and female rats did not significantly alter social interaction and species-typical defensive behavior; however, animals exhibited reduced locomotor activity. Postnatally VPA-exposed female rats demonstrated worsened working memory and decreased exploratory behavior.

Conclusion. Both prenatal and postnatal exposure to VPA elicits behavioral disturbances resembling ASD, with gender-specific nuances, which may guide the direction of pharmacological interventions for the disorder.

Purpose of the study. Studying the blood microcirculation characteristics in the brain and heart of rats with ACM.

Materials and methods. The study was carried out on white outbred male rats. The animals were randomized into 2 groups: 1st (n = 7) — control (intact) rats that received a normal diet and free access to water; 2nd (n = 6) — animals that received a normal diet and a 10 % ethanol solution as the only source of liquid. After 24 weeks of alcoholization in animals, the size and inotropic function of the heart were assessed using echocardiography. The next day, in anesthetized rats (urethane 1300 mg/kg i.p.), blood microcirculation in the heart and brain was recorded using a computerized laser analyzer “LAZMA-D” (manufactured by NPP “Lazma”, Russia) using the LDF 3.0.2.396 program. Using spectral wavelet analysis, the amplitudes of endothelial, neurogenic, myogenic, pulse and respiratory oscillations of microblood flow and the shunting index were determined.

Results. According to echocardiography data, in rats that consumed a 10 % ethanol solution for 24 weeks, ACM is formed, which is accompanied by a decrease in blood microcirculation in the brain and myocardium. Thus, if in control animals the indicator of blood microcirculation in the myocardium was 36.60±2.19 perf. u., then in rats with ACM it was equal to 26.88±1.50 perf. u. units (p = 0.004). In the myocardium of rats with ACM, compared with control animals, the amplitude of both active and passive oscillations of microblood flow was significantly greater.

Conclusion. In rats with ACM, the level of blood microcirculation in the heart muscle is significantly reduced, which, according to the results of spectral wavelet analysis, is prognostically unfavorable.

Relevance. Autism spectrum disorder (ASD) is a developmental disorder of the brain with unclear etiology and pathophysiology, characterized by impaired social communication, stereotypic or repetitive behavior, and varying degrees of mental retardation. One of the environmental factors that have an adverse effect on pregnant women and embryo development is propionic acid (PPA), which is a secondary metabolite of the intestinal microbiota and is widely used as a food preservative. Under physiological conditions, PPC modulates cellular signal transduction, neurotransmitter synthesis and release, cellular interactions, gene expression, immune function, and affects mitochondrial and lipid metabolism. Excessive exposure to PPC can have a number of negative consequences on health and behavior, including leading to the development of ASD.

The aim of present research was to assess behavioral characteristics in male and female Wistar rats with ASD caused by prenatal administration of sodium salt of propionic acid at the early perinatal and juvenile stages of development.

Methods. In a model of ASD induced by prenatal administration of propionic acid at a dose of 500 mg/kg, subcutaneously on days 12–16 of gestation, behavior was assessed in the “nesting” and juvenile periods of life in male and female Wistar rats. Physical and neurological development, social behavior (“Maternal scent”, “Paired test”), repetitive behavior (Y-maze, “Auto-grooming”), motor and exploratory activity (“Mink test”) were assessed.

Results. In Wistar rats prenatally treated with propionic acid, there was a slowdown in the formation of a number of reflexes at the stage of early postnatal development, and at a later stage – a decrease in social behavior, increased stereotypy and aggression, hyperlocomotion and low exploratory activity.

Conclusion. The ASD model induced by prenatal administration of PPC is adequate and suitable for studying means of pharmacological correction of ASD.

GIZh-298 pharmacokinetics was studied in rats after different dosage regimens.

The aim of this study was to study GIZh-298 pharmacokinetics after its multiple intragastric administration.

Methods. The study was conducted on outbred male rats. The concentrations of GIZh-298 in the blood plasma were determined by HPLC with mass-spectrometric detection. Pharmacokinetic parameters were evaluated using a model-independent method.

Results. After single and multiple (4 times with a dosage interval of 3 hours) intragastric administrations at 60 mg/kg dose, the test substance in the blood plasma was determined for 4 hours. The mode of administration of GIZh-298 did not affect the value of its half-life and the mean residence time. It has been established that GIZh-298 accumulates in the rats.