Influence of a Nitric Oxide Synthase Inhibitor on the Anxiolytic, Stimulating, and Analgesic Effects of Long-Term Perinatal Caffeine Exposure in Rats.

We studied the effect of inducible NO synthase (iNOS) inhibitor aminoguanidine on the behavioral effects of chronic perinatal caffeine exposure. Administration of caffeine in the prenatal and early postnatal periods led to the development of anxiolytic, stimulating, and analgesic effects. Administration of aminoguanidine attenuated the anxiolytic and stimulating effects and potentiated the analgesic effect of perinatal administration of caffeine. Chronic perinatal administration of caffeine leads to significant changes in the level of anxiety, motor activity, and pain sensitivity, and inhibition of iNOS has a pronounced multidirectional effect on these effects.

Targeted next-generation sequencing of 21 candidate genes in hereditary ovarian cancer patients from the Republic of Bashkortostan.

About 5-10% of all ovarian cancer cases show familial clustering, and some 15-25% of familial ovarian cancer cases are mediated by high-penetrance mutations in the BRCA1 and BRCA2 genes. Only few other genes have been identified for familial ovarian cancer.We conducted targeted next-generation sequencing of the protein coding region of 21 candidate genes, including UTR regions, in genomic DNA samples of 48 patients with familial ovarian cancer from the Republic of Bashkortostan. We identified deleterious variants in BRCA1, BRCA2, CHEK2, MSH6 and NBN in a total of 16 patients (33%). The NBN truncating variant, p.W143X, had not previously been reported. Seven patients (15%) were carriers of the c.5266dupC variant in BRCA1, supporting a Russian origin of this founder allele. An additional 15 variants of uncertain clinical significance were observed. We conclude that our gene panel explains about one-third of familial ovarian cancer risk in the Republic of Bashkortostan.

Features of the Effects of Glutamatergic System Modulators in the Model of Hyperthermal Seizures in Rat Pups.

We studied the effect of lamotrigine, an anticonvulsant inhibiting the presynaptic release of glutamate, and LY341495, an antagonist of metabotropic glutamate 2/3 receptors, on the development of hyperthermic seizures and the content of LPO products in the brain of 8-10-day-old Wistar rats. Rat pups in the early postnatal period demonstrated pronounced seizures in response to thermal exposure, which was accompanied by an increase in the level of LPO products in the cerebral cortex. It was shown that the latency of generalized seizures increased after administration of both lamotrigine and LY341495. The most pronounced effect was observed in animals treated with lamotrigine. Both test substances prevented LPO intensification induced by hyperthermic exposure to varying degrees.

Relationship between Adenosine Deaminase Activity in the Cerebral Cortex and the Stimulating Effect of Caffeine in Adult Wistar Rats of Different Ages.

The aim of this study was to test the hypothesis that the higher the activity of adenosinedeaminase (ADA) in the brain, the greater should be the motor activity of animals, and possibly the stronger the psychostimulant effect of caffeine. We studied the effect of caffeine (10 and 20 mg/kg) on the motor activity and ADA activity in the frontal cortex of the brain in 2- and 5-month-old rats with different levels of spontaneous motor activity. Total motor activity significantly decreased with age, which was accompanied by a decrease in ADA activity. Administration of caffeine in a dose of 10 mg/kg stimulated motor activity in both 2- and 5-month-old animals, while ADA activity decreased in 2-month-old rats and increased in 5-month-old animals. Administration of caffeine in a dose of 20 mg/kg did not change the motor activity, however, in 5-month-old animals it led to an even greater increase in ADA activity. Thus, the age-related decrease in motor activity can be due to a decrease in ADA activity. However, the effect of caffeine on motor activity is not directly related to ADA activity in the cerebral cortex.

The Development of Pathological Dependence after Intermittent Use of Sodium Glutamate, but Not Sucrose or Sodium Chloride Solutions.

The possibility of development of dependence was studied during the intermittent consumption of sucrose, sodium chloride, and sodium glutamate solutions. Rats were allowed to choose and consume solutions of sucrose, sodium chloride, and sodium glutamate for 28 days. On days 29-31 of the experiment, the animals were deprived of the preferred solutions. On days 32-33, the solutions of sucrose, sodium chloride, and sodium glutamate, but not water were provided again. The consumption of sucrose and sodium chloride solutions did not increase, but consumption of 0.5 and 1% sodium glutamate solutions increased after 3-days withdrawal. The consumption of 2% solution of sodium glutamate was the same before and after withdrawal. The observed effects of sodium glutamate deprivation probably indicate the development of pathological glutamate dependence.

Endogenous Opioid Dependence Induced in Rats by Periodic Intake of 5% Ethanol Solution.

We studied the possibility of formation of endogenous opioid dependence in rats during periodic intake of 5% ethanol solution. In the control group, both drinking bottles contained water. In the experimental group, the second bottle was filled with 5% ethanol solution for 12 h per day; in the following 12 h, these rats were deprived of food and ethanol. This regimen was maintained over 8 days. The rats were subdivided into alcohol- and water-preferring subgroups. Ethanol deprivation followed by naloxone injection evoked the signs of opiate withdrawal syndrome in both subgroups. These findings suggest that periodic voluntary intake of a weak ethanol solution over 8 days led to the formation of endogenous opioid dependence in rats irrespective of amount of the consumed alcohol.

Influence of Caffeine Consumption by Pregnant Rats on Behavior and Learning in Their Offspring.

We studied the effect of long-term prenatal administration of caffeine on the behavior and learning of rats in postnatal ontogeny. Experiments were carried out on male rats born by females receiving caffeine solution as the only source of fluid throughout gestation. The control group consisted of pups obtained from females receiving drinking water throughout pregnancy. It was found that long-term caffeine intake by female rats during pregnancy determined increased locomotor activity of the offspring. Rat pups born from mothers treated with caffeine during pregnancy faster reached the underwater platform in the Morris maze, i.e. demonstrated better spatial memory formation than control animals.

Sex differences in cough reflex.

Majority of patients visiting cough clinics are postmenopausal women, who are affected by intractable cough for years. Why the cough reflex becomes exaggerated in women is not known. Basic research excludes females from the studies contributing to the sex bias which may be responsible for lack of understanding of "hypersensitive" cough in women. Biological and behavioural differences between women and men are the factors affecting cough physiology. Gender also shapes the patterns of behaviour and determines the character of environmental exposures which differs between sexes. The article offers an insight into the physiology of the cough, differences in the maturation of it and biological, social and behavioural factors contributing to the sex differences in cough.

Activation of Peripheral κ-Opioid Receptors Normalizes Caffeine Effects Modified in Nicotine-Dependent Rats during Nicotine Withdrawal.

The study examined the effect of peripheral (intragastric) ICI-204,448, an agonist of gastric κ-opioid receptors, on the psychostimulating and anxiolytic effects of caffeine in nicotinedependent rats at the stage of nicotine withdrawal. In these rats, the effects of caffeine (10 mg/kg) were perverted. In nicotine-dependent rats, caffeine produced an anxiolytic effect accompanied by pronounced stimulation of motor activity, in contrast to anxiogenic effect induced by caffeine in intact rats without nicotine dependence. During nicotine withdrawal, nicotine-dependent rats demonstrated enhanced sensitivity to nicotine. Intragastric administration of κ-opioid receptor agonist ICI-204,448 normalized the effect of caffeine in nicotinedependent rats. We have previously demonstrated that activation of peripheral κ-opioid receptors inhibited central κ-opioid activity and eliminated manifestations of nicotine withdrawal syndrome in nicotine-dependent rats, e.g. metabolism activation, stimulation of motor activity, and enhancement of food consumption. In its turn, inhibition of central κ-opioid structures activates the brain adenosine system, which can attenuate the caffeine-induced effects in nicotine-dependent rats.

Anxiolytic, Psychostimulant, and Analgesic Effects of Various Volumes of Ethanol Solution in Different Concentrations, but in the Same Dose.

We studied the effect of ethanol (dose 2 g/kg) in various concentrations (5, 13, and 40%) and different volumes (40, 15.5, and 5 ml/kg) on the level of anxiety, locomotor activity, and pain sensitivity in rats. Administration of 40 ml/kg water to animals was followed by a significant increase in the time spent in the open arms of the elevated plus maze. Administration of water in a volume of 5 or 15.5 ml/kg had little effect on the level of anxiety. The greater was the volume of intragastrically administered ethanol, the stronger was the anxiolytic effect. The psychostimulant and analgesic effects of ethanol were more pronounced after administration of medium volumes and intermediate concentrations of ethanol-containing solutions. Since administration of these solutions cannot produce maximum blood concentration of ethanol, we believe that the observed effects are mainly related to the direct effect of ethanol on the stomach tissue.

The Guinea Pig Sensitized by House Dust Mite: A Model of Experimental Cough Studies.

The guinea pig sensitized by ovalbumin is the most widely used model to study cough experimentally, as the neurophysiology of the vagus nerve in the guinea pig is closest to humans. Nonetheless, the choice of the antigen remains questionable, which influences the translation of results into clinical medicine. The present study seeks to develop an alternative model of cough study using house dust mite sensitization (HDM). Thirty guinea pigs were divided into the HDM group, ovalbumin (OVA) group, and control group based on their cough response to 0.4 M citric acid. In the HDM group animals were sensitized by 0.25 %HDM aerosol, which they inhaled for 5 min over 5 days, followed by inhalation of 0.5 %HDM in the same protocol. Sensitization was confirmed by a skin test. Symptoms of allergic rhinitis were induced by intranasal application of 15 µl 0.5 %HDM and cough challenges with citric acid were performed. Airway resistance was measured in vivo by Pennock's method. We found that both HDM and OVA-sensitized groups showed a significantly enhanced nasal reactivity and cough response compared with controls. The airway resistance data did not show significant differences. We conclude that the HDM cough model replicates functional aspects of the OVA model, which may make it an alternative to the latter. However, the superiority of the HDM model for experimental cough studies remains to be further explored.

Chronic Cough as a Female Gender Issue.

Cough accompanying acute respiratory tract disorders is a self-limiting phenomenon, and it usually does not require sophisticated management. Chronic cough, in contrast, is a bothersome problem, considerably influencing the quality of life of affected individuals. Specialized cough clinics report that substantial proportion of their patients are middle aged-to-postmenopausal females who cough for years in response to otherwise non-tussigenic stimuli, without a clear underlying disease reason. A newly established entity - 'cough hypersensitivity syndrome' explains pathogenesis of this problem. However, the syndrome has not been generally accepted, and the guidelines regarding the diagnostic protocols and treatment are not yet available. The reason why females cough more than males do is unclear, but the analysis of literature and experience with the chronic cough patients allows selecting three main targets of hormonal background which can contribute to the enhanced coughing in females. They are as follows: increased activity of transient receptor potential (TRP) channels expressed on vagal C-fibers mediating cough, laryngeal hypersensitivity and laryngeal dysfunction with paradoxical vocal cord movement, and mast cells which are known to express receptors for female sexual hormones and are frequently found in the bronchoalveolar lavage in chronic cough patients. In this review we analyze the potential contribution of the factors above outlined to excessive cough in female subjects.

[The search for new candidate genes involved in ovarian cancer pathogenesis by exome sequencing].

Ovarian cancer is one of the most insidious of tumors among gynecological cancers in the world. BRCA1 and BRCA2 mutations are associated with high risk of ovarian cancer; however, they are causative only in a fraction of cases. The search for new genes would expand our understanding of the mechanisms underlying malignant ovarian tumors and could help to develop new methods of early diagnosis and treatment of the disease. The present study involved exome sequencing of eight DNA samples extracted from the blood of ovarian cancer patients. As a result of the study, 53057 modifications in one sample were identified on average. Of them, 222 nucleotide sequence modifications in DNA located in exons and splice sites of 203 genes were selected. On the basis of the function of these genes in the cell and their involvement in carcinogenesis, 40 novel candidate genes were selected. These genes are involved in cell cycle control, DNA repair, apoptosis, regulation of cell invasion, proliferation and growth, transcription, and also immune response and might be involved in development of ovarian cancer.

Effect of peptide agonists of peripheral opioid receptors on operant feeding behavior and food motivation in rats.

We studied the effect of intragastric administration of peptide agonists of µ-opioid receptors (DAMGO) and δ-opioid receptors (DADLE) on food consumption and food motivation during operant feeding behavior of different intensity and effectiveness. To obtain one food granule, trained rats should press a lever 1 time (day 1), 2 times (day 2), 4 times (day 3), 8 times (day 4), 16 times (day 5), or 32 times (day 6). Activation of δ-opioid receptors in the stomach was followed by suppression of feeding behavior at low energy expenditure. The level of food motivation under these conditions practically did not differ from the control. Activation of µ-opioid receptors in the stomach suppressed energy-consuming feeding behavior, which was accompanied by an increase in the level of food motivation. It can be hypothesized that protein metabolites exhibiting µ-opioid activity probably provide afferent signals into CNS via the vagus nerve to terminate energy expenditure under adverse conditions (although food motivation is not satisfied). Food motivation under these conditions probably contributes to the behavior aimed towards the search for more available food.

Method for determining the level of food motivation in rats.

A new method for the quantitative evaluation of the level of food motivation was developed. This method takes into account not only the information, but also the energy component of operant feeding behavior of different intensity and effectiveness with a simultaneous study of metabolism by means of indirect calorimetry. Our experiments showed that an increase in the number of lever pressing episodes (from 1 to 8) to obtain one food granule during operant feeding behavior is accompanied by a progressive decrease in the level of food motivation. The level of food motivation remains practically unchanged with an increase in the ratio of pressing episodes to 16 and 32 (despite consumption of food).

Effect of peripheral opioid receptor agonists on depressive activity of ethanol.

We studied the effect of peripheral µ- and κ-opioid receptor agonists (not crossing the bloodbrain barrier) on locomotor activity and metabolism in rats after acute administration of ethanol. Intraperitoneal injection of ethanol in a single dose of 2 g/kg had a strong depressive effect manifested in a decrease in horizontal locomotor activity and suppression of metabolism. µ-Opioid receptor agonist DAMGO and κ-opioid receptor agonist ICI 204,448 partly abolished the effect of ethanol on locomotor activity of rats. ICI 204,448 was most potent in this respect. In contrast to µ-opioid receptor agonist DAMGO, κ-opioid receptor agonist ICI 204,448 prevented metabolism suppression induced by ethanol. Our results indicate that ICI 204,448 significantly inhibits the depressive effect of ethanol. DAMGO showed only partial effectiveness under these experimental conditions.

Effect of prolyl endopeptidase inhibitor benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine on activity of proline-specific peptidases in brain structures of rats with experimental MPTP-induced depressive syndrome.

A noncompetitive synthetic inhibitor of prolyl endopeptidase benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine (1.0 mg/kg intraperitoneally for 2 weeks) prevented the increase in activity of prolyl endopeptidase in the frontal cortex, striatum, and hypothalamus and activation of dipeptidyl peptidase IV in the frontal cortex of rats with experimental dopamine deficiency-dependent depressive syndrome caused by administration of proneurotoxin MPTP (2 weeks). Our results suggest that the antidepressive effect of prolyl endopeptidase inhibitor is at least partly related to prevention of enzyme activation in the frontal cortex. The antistress effect of this substance can be associated with prevention of enzyme activation in the hypothalamus.

Effect of prolyl endopeptidase inhibitor benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine on the course of experimental depressive syndrome in rats.

The effects of noncompetitive prolyl endopeptidase inhibitor benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine were studied in rats with the experimental dopamine deficiency-dependent depressive syndrome induced by systemic injections of a pre-neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin for 14 days. The inhibitor (3.0 mg/kg, i.p., 30 min before pre-neurotoxin injection on days 8-14) alleviated depression symptoms and promoted normalization of behavioral activity after drug withdrawal. The obtained data reflected therapeutic antidepressant properties of inhibitor for prolyl endopeptidase benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine.

Benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine, a prolyl endopeptidase inhibitor, modulates depression-like behavior of rats in forced swimming test and activities of proline-specific peptidases in the brain structures.

High activities of prolyl endopeptidase and dipeptidylpeptidase IV in the striatum and of prolyl endopeptidase in the frontal cortex were recorded in rats with stress-induced depression-like state (behavioral despair) developed in the Porsolt forced swimming test. Acute injection of benzyloxycarbonyl-methionyl-2(S)-cyanopyrrolidine (prolyl endopeptidase noncompetitive synthetic inhibitor) in a dose of 1 mg/kg prevented the development of behavioral despair and the increase of prolyl endopeptidase and dipeptidylpeptidase IV activities in the brain structures. In a dose of 2 mg/kg prolyl endopeptidase inhibitor did not modify the development of behavioral despair, but prevented the increase of prolyl endopeptidase and dipeptidylpeptidase IV activities in the striatum.