Effects of Blockage of Peripheral Choline, Serotonin, and Dopamine Receptors on Heart Rhythm Variability in Rats under Conditions of Stimulation of Neurotransmitter Systems.

Stimulation of the serotoninergic system (5-hydroxytryptophan, 50 mg/kg; fluoxetine, 3 mg/kg) induced a significant increase in HR and a reduction in the amplitude of all waves of the heart rhythm variability. Stimulation of the dopaminergic system (L-DOPA and amantadine, 20 mg/kg each) resulted in a moderate increase in HR and amplitudes of low-frequency (LF) and very-low-frequency (VLF) waves of the heart rhythm variability. Successive blockade of nicotinic (hexamethonium, 7 mg/kg) and muscarinic cholinergic receptors (atropine, 1 mg/kg) leads to a significant decrease in the variability of cardiointervals (almost to complete levelling) both under control conditions and after stimulation of the neurotransmitter systems. Serotonin receptor blockade (promethazine, 2 mg/kg) did not affect HR, but reduced the amplitude of LF- and VLF-waves. Under conditions of serotoninergic system stimulation, the blockade of serotonin receptors was followed by a significant HR acceleration without changes in heart rhythm variability; blockade of dopamine receptors (sulpiride, 1 mg/kg) induced HR acceleration and increase in the amplitude of LF- and VLF-waves; blockade of dopamine receptors under conditions of dopamine system stimulation was followed by a significant increase in HR and a decrease in the amplitude of all waves of the heart rhythm variability. It can be hypothesized that serotonin- and dopaminergic systems affect the heart rhythm via cardiomyocyte receptors and via modulation of activity of the adrenergic and cholinergic systems. The effects of serotonin- and dopaminergic systems can be considered as synergic in the CNS, and antagonistic at the periphery.

[Effects of cytoflavin on neuronal apoptotic processes in the murine cerebral cortex on a model of physiologicaland pathological aging]. / Vliianie tsitoflavina na protsessy apoptoza neironov kory golovnogo mozga u myshei na modeli fiziologicheskogo i patologicheskogo stareniia.

Involutional changes in the cerebral cortex substantially affect the activity of the cortex itself and the function of target organs. This necessitates pharmacological correction of age-related diseases, primarily a high level of cell death. OBJECTIVE: To investigate the role of cytoflavin in mechanisms for the apoptotic regulation of cerebral cortical cells during physiological and pathological aging (in the presence of HER-2/neu overexpression). MATERIAL AND METHODS: HER-2/neu transgenic mice were used; wild-type FVB/N mice served as controls. The levels of apoptosis (TUNEL) and the expression of its associated proteins (p53, CD95, Mcl-1, p-AKT, and p-ERK) (Western blotting) were estimated in the sensorimotor cortex. RESULTS: Activation of fundamental AKT and ERK survival pathways promotes a low level of cell death in young FVB/N mice; the extrinsic receptor mechanism of apoptosis is observed to be initiated by aging. The high p-AKT levels in the cortical cells provide suppressed cell death in transgenic mice regardless of their age. After cytoflavin administration, the old wild-type mice show a lower level of apoptosis in the cortical neurons apparently due to the increased expression of the anti-apoptotic protein Mcl-1, while the old transgenic mice exhibited suppression of the AKT and ERK survival pathways and, accordingly, activation of the extrinsic receptor and p53-dependent apoptosis pathways. CONCLUSION: Thus, cytoflavin exerts a pronounced neuroprotective effect during physiological and accelerated aging, while its effect on the level of neuronal apoptosis is ambiguous and depends on the genetic line of animals. So, this is a moderate stimulation of apoptosis when its level is low in HER-2/neu mice with a high level of carcinogenesis, as well as a decrease in the high level of apoptosis in old wild-type animals, which prevents neurodegeneration.

Effect of Atropine on Adrenergic Responsiveness of Erythrocyte and Heart Rhythm Variability in Outbred Rats with Stimulation of the Central Neurotransmitter Systems.

Single injection of muscarinic cholinoceptor blocker atropine (1 mg/kg) to outbred male rats reduced ß-adrenergic responsiveness of erythrocytes (by 2.2 times) and the content of epinephrine granules on erythrocytes (by 1.5 times), significantly increased HR and rigidity of the heart rhythm, and manifold decreased the power of all spectral components of heart rhythm variability. Stimulation of the central neurotransmitter systems increased ß-adrenergic responsiveness of erythrocytes (by 15-26%), decreased the number of epinephrine granules on erythrocytes (by 25-40%), and increased HR and cardiac rhythm intensity. These changes were most pronounced after stimulation of the serotoninergic system. Administration of atropine against the background of activation of central neurotransmitter systems did not decrease ß-adrenergic responsiveness of erythrocytes (this parameter remained at a stably high level and even increased during stimulation of the dopaminergic system), but decreased the number of epinephrine granules on erythrocytes, increased HR, and dramatically decreased the power of all components of heart rhythm variability spectrum. The response to atropine was maximum against the background of noradrenergic system activation and less pronounced during stimulation of the serotoninergic system. Thus, substances that are complementary to cholinergic receptors modulated adrenergic effect on the properties of red blood cells, which, in turn, can modulate the adrenergic influences on the heart rhythm via the humoral channel of regulation. Stimulation of central neurotransmitter systems that potentiates the growth of visceral adrenergic responsiveness weakens the cholinergic modulation of the adrenergic influences, especially with respect to erythrocyte responsiveness. Hence, changes in the neurotransmitter metabolism in the body can lead to coupled modulation of reception and reactivity to adrenergic- and choline-like regulatory factors at the level of erythrocyte membranes, which can be important for regulation of heart rhythm.

Effect of Noradrenergic Neurotoxin DSP-4 and Maprotiline on Heart Rate Spectral Components in Stressed and Resting Rats.

The effects of intraperitoneal DSP-4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, a noradrenergic neurotoxin) and maprotiline (an inhibitor of norepinephrine reuptake in synapses) on spectral components of heart rhythm variability were examined in outbred male and female rats treated with these agents in daily doses of 10 mg/kg for 3 days. At rest, DSP-4 elevated LF and VLF spectral components in male and female rats. Maprotiline elevated LF and VLF components in males at rest, increased HR and reduced all spectral components in resting females. Stress against the background of DSP-4 treatment sharply increased heart rate and reduced the powers of all spectral components (especially LF and VLF components). In maprotiline-treated rats, stress increased the powers of LF and VLF components. Thus, the central noradrenergic system participates in the formation of LF and VLF spectral components of heart rate variability at rest and especially during stressful stimulation, which can determine the phasic character of changes in the heart rate variability observed in stressed organism.

Effect of Stimulation of Neurotransmitter Systems on Heart Rate Variability and ß-Adrenergic Responsiveness of Erythrocytes in Outbred Rats.

We studied heart rate variability and ß-adrenergic responsiveness of erythrocytes and changes in these parameters in response to single administration of ß-adrenoblocker propranolol (2 mg/kg) in outbred male rats against the background of activation of the noradrenergic, serotonergic, and dopaminergic neurotransmitter systems achieved by 4-fold injections maprotiline (10 mg/kg), 5-hydroxytryptophan (50 mg/kg) combined with fluoxetine (3 mg/kg), and L-DOPA (20 mg/kg) with amantadine (20 mg/kg), respectively. Stimulation of the noradrenergic system moderately enhanced the heart rhythm rigidity and ß-adrenergic responsiveness of erythrocytes. In addition, it markedly augmented the moderating effect of subsequently administered propranolol on LF and VLF components in the heart rate variability and reversed the effect of propranolol on ß-adrenergic responsiveness of erythrocytes. Stimulation of the serotonergic system dramatically decreased all components in the heart rate variability and pronouncedly enhanced ß-adrenergic responsiveness of erythrocytes. Subsequent injection of propranolol slightly restored all components in the heart rate variability and decreased ß-adrenergic responsiveness of erythrocytes to the control level. Stimulation of the dopaminergic system made the heart rate more rigid due to decrease of all components in the heart rate variability; in addition, it slightly but significantly enhanced ß-adrenergic responsiveness of erythrocytes. Subsequent injection of propranolol produced no significant effects on all components in the heart rate variability and on ß-adrenergic responsiveness of erythrocytes. Stimulation of noradrenergic, serotonergic, and dopaminergic neurotransmitter systems produced unidirectional and consorted effects on heart rate variability and ß-adrenergic responsiveness of erythrocytes, although the magnitudes of these effects were different. Probably, the changes in the heart rate variability in rats with stimulated neurotransmitter systems results from modification of the cellular sensitivity in peripheral organs to adrenergic influences. However, the differences in the reactions to ß-adrenoblocker attest to specificity of the mechanisms underlying the changes in membrane reception and adrenergic pathways in every experimental model employed in this study.

Heart Rate Variability in Nonlinear Rats with Different Orientation and Exploratory Activity in the Open Field.

The basic behavioral activity of nonlinear rats was evaluated from the sum of crossed peripheral and central squares and peripheral and central rearing postures in the open fi eld test. This index was low (<20 episodes), intermediate (20-29 episodes), or high (>30 episodes). Male rats with high score of orientation and exploratory activity were characterized by higher indexes of total heart rate variability than rats with low or intermediate activity. Specimens with a greater contribution of VLF waves into the total power spectrum of heart rate variability were shown to dominate among the rats with high behavioral activity. Our results are consistent with the notions of a suprasegmental nature of VLF waves.

[Comparative experimental study of the influence of drugs that improve brain metabolism (angiogen, cytoflavin) on neuronal apoptosis and function of cerebral cortex during aging].

The safety of cortical neurons and their functional activity is essential for organism at all stages of ontogenesis. However, aging changes leading to an increase in apoptosis level may cause considerable damage to cerebral cortex function, including sensorimotor. We have studied the role of exogenous neurometabolites (angiogen, cytoflavin) in apoptosis regulation and correction of age-related motor and behavioral disturbances. To study the regulation of neuronal morphofunctional activity, we used accelerate-senescent transgenic HER2 mice in comparison to wild type FBV mice. Functional changes in cerebral cortex were studied by the Suok test and open field test, the level of neuronal apoptosis was assessed by TUNEL method, the expression of apoptosis-modulating proteins was detected by immunohistochemistry and Western blotting. We have revealed differences in psycho-emotional and locomotor activity of these strains of mice. In addition, results of our study showed morphological differences: increase in the apoptosis level of cortical neurons in aged FBV type mice, but no changes in aged HER2 mice. The investigated drugs induce cell death of cortical neurons in transgenic mice of both ages and in young wild-type mice by p53-dependent pathway. Increased apoptosis in the cortex of old transgenic mice has important clinical implications, because reduced apoptosis during aging is one of the causes of cancer. The treatment of old wild-type animals reduces elevated neuronal apoptosis, which decreases risk of age neurodegeneration. Thus, revealed morphological changes in the cerebral cortex are the basis for involutional disabilities (including reduced locomotor activity and increased anxiety level). The use of angiogen and cytoflavin treatment improves functional activity of the cortex and protects normal structure of nervous tissue.

Pathways of apoptosis regulation in hepatocytes induced by first-line antitubercular drugs.

We studied pathways of apoptosis regulation during experimental hepatopathy caused by treatment with antitubercular drugs and involvement of some hepatoprotectors and immunomodulators in the regulation of hepatocyte apoptosis induced by antitubercular drugs. The intensity of apoptosis and expression of apoptosis-associated molecules were evaluated. It was shown that antitubercular drugs induce apoptosis in hepatocytes by triggering external signaling pathway and p53-dependent signaling pathway and simultaneously reducing the level of anti-apoptotic Bcl-2 protein. Runihol, remaxol, and cycloferon reduced degenerative effects in the liver, though the level of apoptosis remained high. Ademetionine in tablets and reamberin improved the microstructure of the liver by inhibiting both apoptotic pathways induced by the antitubercular drugs; in other words, they have distinct hepatoprotective and apoptosis-protective effects, which is especially important at the late stages of ontogeny.

Age- and sex-related changes in heart rate variability under conditions of blockade or stimulation of peripheral adrenoceptor in outbred rats.

Changes in heart rhythm variability were studied in male and female mature and 5-6-week-old rats under conditions of 7-day administration of ß1-adrenoreceptor blocker atenolol (2.5 mg/kg) and α1-adrenoreceptor agonist phenylephrine (0.3 mg/kg). Atenolol administration to mature rats was followed by a slight deceleration of cardiac rhythm, a tendency to heart rate variability decrease in the HF range, and moderate increase in centralization of regulation. In 6-week-old rats, increased variability of cardiointervals and significant increase of centralization of the heart rhythm regulation due to an increase in the power of low-frequency waves (specifically VLF) were observed. In both mature and young rats, changes of heart rate frequency and variability in response to atenolol administration were more pronounced in females. Phenylephrine administration was followed by a significant heart rate deceleration, increase in cardiointerval variability and centralization of heart rate regulation in mature rats and by a decrease in heart rate variability in all frequency ranges in 6-week-old rats. In mature rats, changes in heart rate frequency and variability produced by phenylephrine administration were more pronounced in males; in young rats, the most strained heart rhythm developed in females.

[Role of hepatoprotectors and immunomodulators in regulation of hepatocyte apoptosis induced by antituberculosis treatment].

UNLABELLED: It was currently shown that hepatopathy due to drug toxicity is associated with increased apoptosis of hepatocytes. Therefore, development of drugs which regulate cell death is of great importance. AIM: To involve some hepatoprotectors (ademethionine, reamberin, remaxol) and immunomodulators (cycloferon) into regulation of apoptosis in experimental models of liver first-line antituberculousis drugs (isoniazid, rifampicin, pyraztinamide). MATERIALS AND METHODS: Levels of apoptoasis (TUNEL), expression of CD95 (receptor of tumor necrosis factor - by immunohistochemistry), expression of caspase-8, caspase-3 and pS3 (Western-blotting) were measured. RESULTS: Exposition offirst-line antituberculousis drugs leads to dysthrophia of liver parenchyma cells with increased apoptosis of hepatocytes and activation of CD95, caspase-8 (external way) and overexpression of p53 and caspase-3. It was found that reamberin, cycloferon and remaxol have hepatoprotective effect improving liver histology; ademethionine administered by intraperitoneal injection showed no positive effects. Reamberin demonstrated apoptosis-inhibiting effect in the experiment whereas other drugs were found to be apoptosis inductors for hepatocytes in toxic hepatopathy. CONCLUSIONS: Legulation of apoptosis by cycloferon and remaxol mediated by external and p53-dependent pathway is confirmed by increased expression of CD95 and p53 protein. Ademethionine might induce apoptosis by the intrinsic pathway.

[Mechanism of hepatocyte apoptosis in experimental toxic liver injury].

One of the causes of drug hepatopathy is hepatocyte apoptosis, the mechanisms of which are still unclear. The experiments were performed in 24 Wistar rats to study the role of hepatoprotectors in the regulation of hepatocyte apoptosis in liver damage induced by administration of antituberculosis drugs (ATD). The level of apoptosis (TUNEL) was evaluated, and the expression of apoptosis-associated molecules was detected by immunohistochemistry and Western blotting. It was shown that a signaling cascade induced by ATD involved the activation of cell surface receptors (CD95) and caspase-8, i.e. apoptosis was mediated by extrinsic pathway. In addition,ATD induced p53 oncosuppressor synthesis with further activation of caspase-3 effector. Runihol administration during ATD treatment administration improved the condition of the liver, despite some apoptosis stimulating effect, mediated by an intrinsic pathway. It was found that runihol blocked both FAS- and p53-dependent pathways. Ademethionine during drug intoxication acts as a hepatoprotector, blocking extrinsic and p53-dependent pathways.

[Influence the water deprivation and alpha-tocopheroli acetates on the expression of apoptosis regulator proteins].

We revealed ontogenetic features in apoptosis level, apoptosis signal proteins expression, antioxidant (alpha-tocoferoli acetate) effects in neurons of magnocellular hypothalamic centers of BALB-c mice. It was obtained that water deprivation stress leads to apoptosis initiation of neurons in both age groups. Stress-protected action of alpha-tocoferoli acetate was more significantly in young mice compared to old ones. In our subsequent work (immunocytochemical reactions) we obtained further regular occurrences. Dehydration leads to increase of proapoptotic protein Bax synthesis in hypothalamic neurosecretory cells in young mice and in age-independent manner, this stress leads to decrease of antiapoptotic proteins Bcl-2 and Mcl-1 synthesis. So, the apoptosis level increases. More significant antiapoptotic action of alpha-tocoferoli acetate in stress condition in young mice is obviously connected with quick reaction of compensatory mechanisms (low expression of proapoptotic proteins p53, Bax and high expression of antiapoptotic protein Bcl-2).

[Phenotropyl succinate as the means for correction of neuroimmune disturbances under conditions of informational-physical stress].

In Wistar rats, psycho-immune-modulating properties of phenotropyl succinate were studied under conditions of informational-physical stress. The effect ofphenotropyl succinate on the organism specific and unspecific resistance was studied. The data obtained indicate the phenotropyl succinate ability to release neuroimmune disturbances developing under conditions of informational-physical stress.

Psychoimmunomodulatory effect of phenotropil in animals with immune stress.

We studied the effect of phenotropil (25 mg/kg intraperitoneally, 5 days) on the immune and psychoemotional state of Wistar rats with LPS-induced immune stress. Hyperactivity of the immune system in animals after treatment with Pseudomonas aeruginosa LPS (100 µg/kg intraperitoneally, 3 days) manifested in a significant increase in the delayed-type hypersensitivity index, antibody titer in the reaction of passive hemagglutination, and phagocytic activity of peripheral blood neutrophils. Locomotor, orientation, and exploratory activities were reduced, while anxiety increased in animals with immune stress. Phenotropil exhibited the psychoimmunomodulatory effect under these conditions, which manifested in prevention of anxiety and fear response, increase in horizontal locomotion and exploratory behavior, and improvement of immunoreactivity.

[Age and sex features of antioxidation protection and free-radical processes in white rats brain].

With the years, the activity of antioxidation enzymes and speeds of its free-radical oxidation in different molecules changes. These changes depend also on an animal sex. The brain tissue is especially subjects to oxidising destruction and has the features of antioxidation protection. Level of free-radical processes and activity of basic components of antioxidation link in the different parts of the central nervous system has been investigated. The young animals demonstrated most sex differences in big hemispheres and in intermediate brain, and in a less degree in the middle brain, cerebellum and oblong brain. Sex differences in spinal cord of young animals were not revealed. In aging of animals of different sex, the level of free-radical processes and activity of enzymatic antioxidants changes with unequal speed, and these changes often have an opposite orientation.

[Immune-regulating effect of phenibut under lipopolysaccharide-induced immune stress conditions].

The immunoregulating effect of phenibut has been demonstrated on the model of immune stress caused by the injection of lipopolysaccharide from Pseudomonas aeruginosa. The degree of expression of the specific (in a delayed-type hypersensitivity reaction and passive hemagglutination) and nonspecific (phagocytic activity of neutrophils) links of immunomodulation was studied. The formation of lipopolysaccharide (LPS) induced immune stress is characterized by the increase of the indicated parameters of immunity. It is found that phenibut (under intraabdominal injection of 25 mg/kg within 5 days) removes the manifestations of hyperreactivity of the cellular link of immunity, and also restores the amount of phagocytic cells, which is evidence of the immunomodulating properties of the drug under conditions of hyperimmunization.

[Changes in the psycho-emotional state under conditions of suppressed immunogenesis, the correction of the disorders with GABA-positive means].

Behaviour and immune responses of rats and mice following cyclophosphamide administration were investigated. The psycho-immunomodulating effect of the GABAergic compounds was revealed. Phenibut (25 mg/kg) and Baclophen (10 mg/kg) restored functional activity of immune system and corrected disturbances of the behavioural responses. The GABAergic agents restored horizontal and direction investigation activities in the rats and mice, decreased grooming and increased number of passages through central zones in the "Suok" test.

Cluster analysis of extracardiac control of the heart rate in random-bred albino rats at rest.

Heart rate variability was examined in random-bred albino rats at rest. The rats were clusterized according to activity of autonomic contour of heart rate control. Combination of factor and cluster analyses enhanced informative value of spectrum parameters of the heart rate variability in nonlinear rats grouped by initial neurovegetative status. The contours of central and autonomic regulation describe the most general features of the control influences that realize modulating influences at the heart level via sympathetic and parasympathetic control pathways. Their activity is comprehensively assessed by the normalized power spectrum of variations in the heart rate.

[Age- and sex-related differences of neuroendocrine center reactions in the hypothalamus on preparation thymalin and alpha-tocopherol acetate].

In experiment the action of Thymalin, alpha-tocopherol and stress on the centers of hypothalamus related to the regulation of the gonadotropic function has been investigated and the age-specific features of such influence as well. The results of experiments indicate the presence of neuron's reaction of the rostra preoptical area and arcuate nucleus for experimental influences. As a stress exposure and alpha-tocopherol injection to the young animals a reduction of neuron's kernels of the arcuate nucleus was observed, a sexual distinction wasn't revealed in the process. The response age-specific feature for alpha-tocopherol injection of the nucleus neuron's rostra preoptical and arcuate area of the hypothalamus of white rats is a reduction in a degree of response. Thymalin reduces a threshold of sensitivity of the neuron's arcuate center to action of stress.

[Age, structural and biochemical characteristics of endometrial secretion in patients with hysteromyoma].

In the given work clinical and laboratory data of 549 patients of different age groups have been analyzed and tested; 194 (35.3%) of them were in reproductive age, 217 (39.5%) in premenopausal age, 138 (25.14%) in meno- and postmenopausal age. The new method of diagnostics of hyperplastic processes of myoendometrium has been worked out and tested; it is based on the comparison of showings of the content of biomolecular peroxide oxidation products in the investigated biological liquids (endometrial washes or menstrual discharges) as well as evaluation of their morphostructural peculiarities.