[Method of complex therapy of chronic cystitis].

AIM: To assess the effectiveness of hydroxyethyldimethyldihydropyrimidine (trade name Xymedone) in the treatment of chronic recurrent cystitis in women. MATERIALS AND METHODS: The study included 30 patients (the main group) with a confirmed diagnosis of chronic cystitis (HC) with a recurrence rate of at least 3 times a year, the average age of the patients was 46.0+/-2.7 years. The control group consisted of 30 age-comparable patients with a similar diagnosis, who underwent standard treatment for this disease. The article presents the results on the effectiveness of the use of hydroxyethyldimethyldihydropyrimidine (Xymedone) in the treatment of HC after anti-inflammatory and local treatment with collargol instillations, and the terms for the regeneration of the bladder mucosa are determined. To patients of the main group Xymedone was prescribed in a dose of 500 mg 3 times a day for 30 days after the completion of local treatment. Control cystoscopy was performed 15 and 30 days after the start of the drug, 3 days after its withdrawal. RESULTS: The planned treatment was completed by all 30 patients of the main group. After 15 days from the date of administration of Xymedone most of patients had no low urinary tract symptoms (LUTS), in comparison with the control group. Cystoscopy performed at this time allowed to establish a positive trend while taking Xymedone in the process of restoring the bladder mucosa after influence of collargol. Hyperemia in the neck and triangle area persisted in most patients, and only in 8 (26.6%) it decreased. Treatment with Xymedone was continued. After 30 days of drug intake laboratory parameters were according to normal values, a significant increase in functional capacity of the bladder (189,5+/-19,8 ml) and volume of urination (147,9+/-26,7 ml.) was detected, the thickness of the bladder wall in a state of filling in the averages was 3.5+/- 0.3 mm, which corresponded to the norm. Cystoscopy, performed 3 days after canceling of the drug, showed a slight hyperemia in the bladder neck area only in one patient. Recurrence of HC in the control group occurred within 6 months after completion of treatment in 15 (51%) women. In the main group there were no relapses during two years of dynamic follow-up. CONCLUSIONS: Hydroxyethyldimethyldihydropyrimidine, included in the therapy of HC, accelerates the regeneration of the bladder mucosa after local treatment of recurrent cystitis and shortens the period of its recovery, significantly lengthens the period of persistent remission.

Influence of the Activation of NMDA Receptors on the Resting Membrane Potential of the Postsynaptic Cell at the Neuromuscular Junction.

Impaired function or insufficient expression of glutamate N-methyl-D-aspartate (NMDA) receptors underlies a number of brain pathologies; these receptors are, therefore, regarded as a pharmacological target for many neuroactive drugs. It was shown that in the CNS, this type of glutamate receptors participate in the processes of neuronal excitation, synaptic plasticity [1, 2], and excitotoxicity in neurodegenerative diseases and are also involved in the pathogenesis of epilepsy and seizures. However, until recently, the presence and activity of NMDA receptors beyond the CNS had never been considered. This research shows that activation of NMDA receptors at the mammalian neuromuscular junction alters the resting membrane potential of the postsynaptic cell evoked by cation entry through the receptor-associated channel.

ATP Reduces the Entry of Calcium Ions into the Nerve Ending by Blocking L-type Calcium Channels.

At neuromuscular junctions, ATP inhibits both the evoked and spontaneous acetylcholine release and inward calcium current operating via presynaptic P2Y receptors. It was shown in the experiments with the frog neuromuscular synapse using specific calcium-sensitive dye Oregon Green Bapta 1 that exogenous ATP reduces the amplitude of calcium transient, which reflects the changes in the entry of calcium ions in response to the nerve pulse. The depressing effect of ATP on the transient was prevented by suramin, the blocker of P2 receptors. Nitrendipine, a specific blocker of L-type calcium channels, per se decreased the calcium transient amplitude and significantly attenuated the effect of ATP on the calcium signal. Contrariwise, the preliminary application of ATP to the neuromuscular junction completely eliminated the depressing effect of nitrendipine on the calcium response. The obtained data suggest that an essential component in the inhibitory action of ATP on the calcium transient amplitude is provided by reduction of the entry of calcium ions into a frog nerve ending via L-type voltage-gated calcium channels.

Involvement of dihydropyridine-sensitive calcium channels in high asynchrony of transmitter release in neuromuscular synapses of newborn rats.

Experiments on neuromuscular synapses of rats at different stages of ontogenesis have been performed. It has been found that one of the reasons of higher asynchrony of the release of single quanta of acetylcholine in the synapses of newborn animals is the activity of the presynaptic dihydropyridine-sensitive calcium channels of the L-type.

Presynaptic nicotinic cholinoreceptors modulate velocity of the action potential propagation along the motor nerve endings at a high-frequency synaptic activity.

Experiments on frog neuromuscular junctions have demonstrated that asynchrony of the acetylcholine quantal release forming the multi-quantal evoked response at high-frequency synaptic activity is caused, in particular, by a decrease in velocity of the action potential propagation along the non-myelinated nerve endings, which is mediated by activation of the α7 and α4ß4 nicotinic cholinoreceptors.

6-Methyluracil derivatives as acetylcholinesterase inhibitors for treatment of Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is the major age-related progressive neurodegenerative disorder. The brain of AD patients suffers from loss of cholinergic neurons and decreased number of synapses [1]. AD is caused by an imbalance between Aß production and clearance, resulting in increased amount of Aß in various forms [2]. Reduction of Aß production and increasing clearance of Aß pathogenic forms are key targets in the development of potential therapeutic agents for AD treatment. Unfortunately, only nosotropic approaches for treatment of AD are currently effective in humans. These approaches mainly focus on the inhibition of brain acetyl-cholinesterase (AChE) to increase lifetime of cerebral acetylcholine [3]. It is important to emphasize that AChE itself promotes the formation of Aß fibrils in vitro and Aß plaques in the cerebral cortex of transgenic mouse models of AD [4]. This property of AChE results from interaction between Aß and the peripheral anionic site of the enzyme (PAS) [5]. Dual binding site inhibitors of both catalytic active site (CAS) and PAS can simultaneously improve cognition and slow down the rate of Aß-induced neural degeneration. Unfortunately, the assortment of AChE PAS ligands is still extremely limited. OBJECTIVE: To study putative advantages of AChE non-charged PAS inhibitors based on 6-methyluracil derivatives for the treatment of Alzheimer's disease. METHODS: In vitro studies. Concentration of drug producing 50% of AChE/BuChE activity inhibition (IC50) was measured using the method of Ellman et al. [6]. Toxicological experiments were performed using IP injection of the different compounds in mice. LD50, dose (in mg/kg) causing lethal effects in 50% of animals was taken as a criterion of toxicity [7]. The ability of compound to block in vitro AChE-induced Aß1-40 aggregation was studied using a thioflavin T (ThT) fluorescent probe [8].In vivo biological assays. For in vivo blood-brain barrier permeation assay brains were removed 30 min after IP injection of LD50 dose of tested compound injection. The inhibitory potency was measured using the method of Ellman.Scopolamine and transgenic models of AD were used to evaluate the influence of compound 35 on spatial memory performance.Water solution of scopolamine was injected to mice (ip) 20 minutes before starting memory test during 14 days [9]. Mice were assigned to 7 groups, including 4 groups receiving injection (ip) of compound in different dosages, donepezil-treated mice (donepezil is conventionally used to treat Alzheimer's disease), positive and negative control groups. Double transgenic (APP/PS1) mice expressing a chimeric mouse/human amyloid precursor protein and a mutant of human presenilin-1 [10] were assigned to 4 groups, including transgenic animals injected (ip) with compound 35 or donepezil solution, positive (transgenes injected with water) and negative (wild-type mice) controls.To evaluate spatial memory performance, mice were trained on a reward alternation task using a conventional T-maze [11]. The criterion for a mouse having learned the rewarded alternation task was 3 consecutive days of at least 5 correct responses out of the 6 free trials.For ß-amyloid peptide load was evaluated quantitatively as a number and summary area of Thioflavine S fluorescent spots in cerebral cortex and hippocampal images using Image J program. Statistical analyses were performed using the Mann-Whitney test. RESULTS: We evaluated the acute toxicity of the most active compounds. The most potent AChE inhibitor compound 35 (IC50 (AChE) = 5 ± 0.5 nM) exhibited the lowest LD50 values (51 mg/kg) and inhibited brain AChE by more than 71 ± 1%. Compound 35 at 10 nM, exhibited a significant (35 ± 9%) inhibitory activity toward human AChE-induced Aß aggregation.Scopolamine injection induced significant decrease in correct choice percentage in T-maze, as well as decrease in percentage of mice reaching criterion for learning the task by day 14. This memory deficit was relieved to some extent either by compound 35 (5 mg/kg) or donepezil (reference compound) treatment (0.75 mg/kg). Interestingly, higher doses of compound 35 (10 and 15 mg/kg) produced less therapeutic effect on spatial memory deficit.Group of APP/PS1 mice showed 3 times lower percentage of reaching behavioral criterion and lower percentage of correct choice in T-maze alternation task comparing to WT mice, whereas compound 35 (5 mg/kg) or Donepezil treatment effectively improved these parameters in APP/PS1 mice.Compound 35 treatment (5 mg/kg) during 14 days significantly reduced percentage of summary area and number of ß-amyloid peptide (ßAP) deposits visualized in sections of cerebral cortex, dentate gyrus, and hippocampal CA3 area in APP/PS1 mice. The most prominent reduction of ßAP load by compound 35 treatment was found in CA3 area and cerebral cortex. Meanwhile, Donepezil treatment (1 mg/kg) during 14 days significantly reduced ßAP load in cerebral cortex but not in dentate gyrus and CA3 area. CONCLUSIONS: Experiments showed that the most potent AChE inhibitor compound 35 (6-methyluracil derivative) permeated the blood-brain barrier, improved working memory in the APP/PS1 transgenic mice and significantly reduced the number and area of Aß plaques in the brain. Thus, compound 35 is a promising candidate as a bi-functional inhibitor of AChE for treatment of AD.

Immunohistochemical evidence of the presence of metabotropic receptors for γ-aminobutyric acid at the rat neuromuscular junctions.

in the synapses of the "fast" (m. EDL) and "slow" (m. soleus) skeletal muscles of the rat GABABR1 and GABABR2 subunits of metabotropic receptors for γ-aminobutyric acid (GABA), located primarily on the motor nerve ending membrane were detected by immunohistochemistry and fluorescence microscopy methods.

Hydrodynamic flow in a synaptic cleft during exocytosis.

It is shown that exocytosis in a chemical synapse may be accompanied by "microjet" formation due to the overpressure that exists in the vesicles. This mechanism may take place either at complete fusion of a vesicle with the presynaptic membrane or in the so-called kiss-and-run mode of neurotransmitter release. A simple hydrodynamic model of the viscous incompressible flow arising in the synaptic cleft is suggested. The occurrence of hydrodynamic flow (microjet) leads to more efficient transport of neurotransmitter than in the case of classical diffusive transport.

Voltage-dependent P/Q-type calcium channels at the frog neuromuscular junction.

It is well known that antagonists of N-type voltage-gated calcium channels inhibit the evoked quantal release of acetylcholine in amphibian neuromuscular synapses. This, however, does not exclude the functional expression of other types of voltage-gated calcium channels in these nerve terminals. Using immunocytochemistry, we detected the expression of the alpha1A subunit of P/Q-type calcium channels (that is otherwise typical of mammalian motor nerve endings) in the frog neuromuscular junction. In addition, we demonstrated that the P/Q-type channel blocker omega-agatoxin IVA (20 nM) reduced the action potential-induced calcium transient and significantly decreased both spontaneous and evoked mediator release. Our data indicates the functional expression of P/Q-type calcium channels in the frog motor nerve ending which participate in acetylcholine release.

Immunocytochemical demonstration of M(1) muscarinic acetylcholine receptors at the presynaptic and postsynaptic membranes of rat diaphragm endplates.

M(1)-muscarinic acetylcholine (ACh) receptors (M(1)R) were directly demonstrated immunocytochemically in electronmicroscopic images of rat diaphragm neuromuscular junctions (NMJ). Specific electron-dense granules were located at presynaptic nerve ending membranes and in the sarcolemma in the depths of postsynaptic folds. This first visualization of M(1)R on both sides of the NMJ is in agreement with previous pharmacological data on the regulatory role of M(1)R in quantal and non-quantal ACh release.