[The neurotoxicity biomarkers as potential indicators of the spinal cord ischemia]. / Biomarkery neirotoksichnosti kak potentsial'nye indikatory ishemii spinnogo mozga.

The study aimed at assessing the level of glutamate receptors antibodies (Abs) in blood serum and cerebrospinal fluid (CSF) of patients with spinal cord ischemia along with traditional diagnostic approaches. MATERIAL AND METHODS: Forty patients with spinal cord ischemia (10 with spinal stroke and 30 with subacute and chronic course of the disease) were enrolled. After exclusion of some participants, 27 patients continued the study. Comparison groups included 30 patients with ischemic stroke and 30 patients with radiculopathy. The control group consisted of 15 healthy volunteers. All participants underwent a neurological examination and spinal cord magnetic resonance imaging (MRI). Abs to glutamate receptors (NR2 subunits of NMDA-receptors, AMPA/kainate receptors) were measured by ELISA. RESULTS: NR2 Abs in patients with spinal cord ischemia were significantly increased in serum (p=0.0001) and CSF (p=0.0005) compared to controls and comparison groups. The NR2 Abs reliably differentiated spinal cord ischemia compared to AMPA/kainate receptors and S100ß protein. On the other hand, increased levels of Abs to the AMPA/kainate have been detected in patients with a more severe impairment associated with extensive white matter damage. CONCLUSION: The results show the potential of the Abs to glutamate receptors assessment in the diagnosis of spinal cord ischemia and severity of the process.

[The biomarkers of cerebral ischemia as a new method for the validation of the efficacy of cytoprotective therapy]. / Biomarkery ishemii golovnogo mozga kak novyi metod dokazatel'stva éffektivnosti neirotsitoprotektorov.

AIM: To study blood plasma concentrations of NR2-peptide in patients with ischemic stroke (IS) to assess its diagnostic value as a biomarker of cerebral ischemia and determine the dynamics of the biomarker during treatment with cortexin. MATERIAL AND METHODS: One hundred and twenty patients, aged from 18 to 70 years, including 36 with transient ischemic attack (TIA) and 84 with IS in the carotid territory (n=70) and vertebral/basilar territory with the Wallenberg-Zakharchenko syndrome (n=14), were enrolled. The National Institute of Health Stroke scale (NIHSS) was used to assess neurological status. Blood plasma concentration of NR2-peptide was measured in all patients at admission and after treatment. All laboratory results were compared with neuroimaging (MRI, CT) data. RESULTS: Concentrations of NR2-peptide detected in all patients were higher than in controls (>1.5 ng/ml), p<0.0001. The direct correlation between NR2-peptide (from 3.38 ng/ml to 15.6 ng/ml) and ischemic lesion (from few to 80 mm) was observed. A decrease in NR2-peptide concentration (from 8.5 to 5,.9 ng/ml, p<0.0001) was noted in patients treated with cortexin after 10-day treatment course. CONCLUSION: NR2-peptide blood assay is a reliable hemotest of brain ischemia. Cortexin has a sufficient therapeutic efficacy.

Intracerebroventricular administration of substance P increases dopamine content in the brain of 6-hydroxydopamine-lesioned rats.

The interactions existing between substance P- and dopamine-positive neurons, notably in the basal ganglia, suggest that substance P may have therapeutic use in treatment of Parkinson's disease characterized by impaired dopaminergic transmission. The effects of intracerebroventricularly administered substance P were tested on the levels of dopamine and its metabolites in the striatum, nucleus accumbens and frontal cortex of 6-hydroxydopamine-lesioned rats. Intracerebroventricular injection of 6-hydroxydopamine decreased the levels of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the brain structures under investigation. Administration of substance P in low dose (0.35 nmol/kg) had no effect on the 6-hydroxydopamine-induced reduction of the dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid contents in the brain. However, treatment with substance P in higher dose (3.5 nmol/kg) increased the concentrations of dopamine and its metabolites in the striatum, nucleus accumbens and frontal cortex relative to saline-treated group. Additionally, 6-hydroxydopamine lesions significantly increased 3,4-dihydroxyphenylacetic acid/dopamine and homovanillic acid/dopamine ratios in the striatum and nucleus accumbens. Substance P (3.5 nmol/kg) partially reversed lesion-induced increases in 3,4-dihydroxyphenylacetic acid/dopamine and homovanillic acid/dopamine ratios in the striatum, but did not alter these ratios in nucleus accumbens. To test whether substance P fragmentation is responsible for this phenomenon, substance P(5-11), which is one of the main substance P fragments in rat CNS, was administered in equimolar dose. Substance P(5-11) was found to have no effect on the content of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the striatum and nucleus accumbens. In the frontal cortex, substance P(5-11) produced decreases in dopamine levels and increases in homovanillic acid/dopamine ratio. The results of this study suggest that substance P helps to restore dopamine deficit in the brain in an animal model of Parkinson's disease, with the positive effects being more prominent on the nigrostriatal than on the mesocorticolimbic dopaminergic system, but substance P(5-11) is not responsible for this effect.

Analysis of L-[3H]-glutamate radioligand binding to plasma membranes of the ampullae of Lorenzini of skates.

Radioligand binding analysis of L-[3H]-glutamate to plasma membranes of the ampullae of Lorenzini in the skate revealed one type of binding site with KD = 286 nM and Bmax = 2.1 pmol mg-1 protein. It was revealed that Na+, K+, Ca2+ and Mg2+ inhibited the L-[3H]-glutamate binding, while Cl- had no effect. The glutamate agonists kainate, quisqualate and N-methyl-D-aspartate (NMDA) were shown to inhibit glutamate binding in a dose-dependent manner. The results obtained confirm the electrophysiological observations suggesting the existence of three types of glutamate receptor at afferent synapses of the ampullae of Lorenzini of skates.

The presence of autoantibodies to N-terminus domain of GluR1 subunit of AMPA receptor in the blood serum of patients with epilepsy.

We have analyzed the serum from patients with refractory epilepsy for the presence of autoreactive antibodies to AMPA glutamate receptor subunits. The presence and the level of autoantibodies were assessed using immunoblot and ELISA with synthetic peptides specific for subregions of AMPA glutamate receptor subunits. Patients with refractory epilepsy exhibited strong immunoreactivity to GluR1 subunit compared to healthy donors and patients with Parkinson's disease and Alzheimer's disease. Weak immunoreactivity to other AMPA glutamate receptor subunits was also detected and the signal was diminished in the raw GluR4>GluR3>GluR2. The occurrence of autoantibodies to specific neurotransmitter subunits in the sera of patients with refractory epilepsy suggest that autoimmune process may underlie this disorder.

Mechanisms of the influences of the central administration of substance P on ethanol consumption in chronically alcoholic rats.

The effects of central administration of substance P (SP) on alcohol consumption and dopamine metabolism in the projections of the mesocorticolimbic and nigrostriatal systems of the brain were studied in chronically alcoholic rats. Rats received 15% ethanol solution for 6 months without choice. Intraventricular administration of SP (1 microg/rat) decreased consumption of 10% ethanol solution by 41% compared with controls in an alcohol free choice test lasting one day. After chronic alcoholism, there was a decrease in the ratio of dihydroxyphenylacetic acid (DOPA) and homovanillic acid (HVA) to dopamine in the nucleus accumbens and striatum in rats subjected to alcoholism, as compared with intact controls. Chronically alcoholic rats treated with SP showed increases in DOPA, HVA, and the DOPA:dopamine and HVA:dopamine ratios in the nucleus accumbens as compared with animals given physiological saline, by 17%, 23%, 9% and 19% respectively. The only increases in the striatum were in the absolute levels of DOPA and HVA, by 28% and 29%, while the ratios of these metabolites to dopamine remained unchanged. Thus, central administration of SP decreased the voluntary consumption of ethanol in the ethanol free choice test and enhanced dopamine metabolism in structures of the mesolimbic and nigrostriatal systems in chronically alcoholic rats.

Receptor binding of glutamate in the striatum of rats differing in learning capacity.

A comparative investigation has been carried out for the first time of the receptor binding of glutamate with synaptic membranes and coarse fractions of the postsynaptic enlargements isolated from the striatum of rats differing in their capacity to develop an alimentary instrumental reflex. It was demonstrated that the number of that glutamate binding sites on the postsynaptic enlargements isolated from the striatum of rats capable of rapidly developing an alimentary instrumental reflex was increased as compared with animals not subjected to training. This relationship is maintained two months after the termination of training.

The effects of substance P after central administration on the activity of the mesolimbic system of the rat brain as studied by microdialysis.

In vivo microdialysis was used to study the effects of substance P on dopamine, dihydroxyphenylacetic acid, and homovanillic acid levels in the nucleus accumbens in rats. Each animal received sequential injections of physiological saline, 0.1 microg of substance P, and 1 microg of substance P into the lateral ventricle over three days. Dialysates showed increases in dopamine levels in response to neuropeptide, by 41% for the 0.1 microg dose and 71% for the 1 microg dose. The dynamics of these changes also depended on the concentration of the agent. Administration of 1 microg of substance P gave a peak dopamine level at 50 min; the neurotransmitter level remained significantly elevated 75 min after dosage with substance P. The dopamine level was increased only at 75 min when the 0.1 microg dose of neuropeptide was used. Changes in metabolite levels were also dose-dependent. After the 1 microg dose, the dihydroxyphenylacetic acid level increased by 28%, while the 0.1 microg dose produced no significant change in the level of this metabolite. The homovanillic acid level did not respond to administration of substance P at either dose. These data support the suggestion that the influence of substance P on the internal compensation system is to a significant extent mediated by dopaminergic mechanisms and provides a possible explanation for the effects of the neuropeptide seen in a conditioned place preference reflex.

[Autoantibodies to glutamate receptor subtypes--markers of functional brain damage: their diagnostic significance for detecting paroxysmal activity and ischemia]. / Autoantitela k podtipam glutamatnykh retseptorov--markery funktsional'nogo porazheniia golovnogo mozga: ikh diagnosticheskoe znachenie dlia vyiavleniia paroksizmal'noi aktivnosti i ishemii.

A new direction in diagnostics and the control of pharmacological treatment of brain disorders is discussed. Problems which are considered in the review have significance for understanding the neurochemical mechanisms of paroxysmal activity and brain ischemic stroke. The identification of autoantibodies for glutamate receptors, thought to be involved in these brain disorders, presents a new approach toward characterization of clinical states of individuals and could have a wide application for control of efficiency of pharmacological treatments.

[Effect of substance P on ethanol consumption in subchronically alcoholized rats in the limited scheduled access paradigm]. / Vliianie substantsii P na potreblenie étanola u subkhronicheski alkogolizirovannykh krys v teste ogranichennogo dostupa k alkogoliu.

The effect of substance P on alcohol intake was studied in rats using a limited scheduled access paradigm. Ascending doses of substance P (100 and 200 micrograms/kg) were administered intraperitoneally to rats approximately 30 minute prior to their 1-hour-per-day access to alcohol. Each dose was administered for 3 successive days, and the effect of substance P was compared to that of saline solution control. Substance P at the dose of 100 micrograms/kg had no effect on alcohol consumption but significantly decreased the alcohol intake at the dose of 200 micrograms/kg. Thus, substance P reduces the alcohol motivation of rats in a limited scheduled access paradigm.

[An analysis of the importance of low-molecular peptides in regulating human motor functions in diseases of the central nervous system]. / Analiz znacheniia nizkomolekuliarnykh peptidov v reguliatsii dvigatel'nykh funktsii cheloveka pri nekotorykh zabolevaniiakh tsentral'noi nervnoi sistemy.

The clinical data obtained on the treatment of motor disorders with intrathecal administration of low-molecular peptides, suggest that the peptides are effective in Parkinsonian disease, extrapyramidal hyperkineses and in spinal cord disturbances.

[The function of glutamate receptors in the membrane vesicules, proteoliposomes and hybrid cells of the neuroblastoma N18Tg2a]. / Funktsii glutamatnykh retseptorov v membrannykh vezikulakh, proteoliposomakh i gibridnykh kletkakh neiroblastomy N18Tg2a.

The transport and selective functions of the glutamate-binding proteins of the rat brain cortex synaptic membranes, were studied. The data on kinetics of absorption of the ions 22Na+, 86Rb+ and 45Ca++ by the membrane vesicles and liposomes containing receptor proteins, are presented. The specific features of the c. n. s. glutamate receptors functioning in the hybrid cells of the neuroblastoma N18Tg2a, are revealed. A selective activation of transport of the 22Na+ ions was found in this kind of model systems in presence of physiological concentrations of L-glutamate. The modelling of the glutamate receptors function depended on composition of lipids, presence of the endogenous peptide agent inhibiting binding of the H3-L-glutamate, and on the degree of the neuroblastoma differentiation. Monoclonal antibodies obtained for the receptor's recognizing areas blocked the functions of the glutamate-binding proteins in all the model systems.

[Neurochemical aspects of therapeutic electric stimulation]. / Neirokhimicheskie aspekty lechebnoi élektricheskoi stimuliatsii.

Comparative analysis of the CSF and blood protein-peptide composition in Parkinsonian patients performed with the aid of indwelled electrodes prior to and after therapeutic electrical stimulation (TES) of the brain subcortical structures, revealed a therapeutic effect in the form of reduced muscular rigidity and a mental activation with a positive emotional response. After the TES the protein content in the biological fluids tended to become normalized and the the range of low-molecular protein-peptide fractions changed. A high-performance liquid chromatography, bidimensional electrophoresis and thin-layer chromatography revealed about 5-6 factors of peptide nature with the molecular mass less than 5000 daltons in the CSF and blood after the TES. These factors were shown to exert a biological effect upon muscle preparation of the leech.

[Levels of autoantibodies to glutamate receptors and immunological blood parameters in patients with epilepsy]. / Uroven' autoantitel k sub''edinitsam glutamatnykh retseptorov i immunologicheskie pokazateli krovi u bol'nykh épilepsiei.

The role of glutamate receptors in the brain spiking activity was evaluated. The electroencephalographic (EEG) spiking activity was monitored and autoreactive antibodies (aAbs) to subunits of glutamate receptors were assessed in the blood serum of epileptic and ischemic stroke patients. We showed that the level of GluR autoantibodies in blood serum of patients correlates to the intensity of the brain paroxysmal activity. These data confirm our previous observations. The level of GluR1 aABs has been proposed as a specific biomarker typical for epilepsy. This approach could be recommended as an additional criterion for diagnostic of nervous diseases such as epilepsy and ischemic stroke.

[Autoantibodies against NMDA-receptors in the blood of patients with acute disorders of cerebral circulation]. / Autoantitela k NMDA-retseptoram v krovi bol'nykh s ostrymi narusheniiami mozgovogo krovoobrashcheniia.

Concentration of autoantibodies to human brain NMDA-receptor in blood serum of patients with acute brain ischemic stroke was significantly higher than in healthy persons and patients with other neurological diseases. Average content of cholesterol, lipid peroxides and glutamate in the serum were close in all patient groups investigated. It was suggested that the content of autoantibodies to human brain NMDA-receptor could be used as biochemical criteria for acute brain stroke patient's condition control and their treatment efficiency.

[Level of autoantibodies to opiate receptors in blood of patients with opiate addiction]. / Issledovanie urovnia autoantitel k opiatnym retseptoram v krovi bol'nykh opiinoi narkomaniei.

The level of autoantibodies to opiate receptors was measured in serum of heroin addicts in withdrawal and in the period of long-term abstinence and in healthy volunteers as well. The level of autoantibodies was assessed with ELISA with synthetic peptide specific for subregions of mu and delta opiate receptors. The scores of the level of autoantibodies higher than 150% of the level noted in healthy volunteers was observed in 56% of heroin addicts. The dependence of autoantibodies level from duration of diseases was shown. Elevated level of opiate receptors autoantibodies were detected in the sera of 71% patients with opiate addiction who had been using heroin more then one year. High levels of opiate receptors autoantibodies were observed more frequently in patients with opiate withdrawal syndrome then in patients with long-term remission. Elevated level autoantibodies to opiate receptors were determined in the blood of 38% opiate abusers with remission for 3-8 months. The level of autoantibodies to opiate receptors may be used for diagnostics of heroin dependence and control of treatment efficiency.

[The pharmacological characteristics, immunochemical identification and study of the location of quisqualate receptors in the rat and human brains]. / Farmakologicheskaia kharakteristika, immunokhimicheskaia identifikatsiia i issledovanie lokalizatsii kviskvalatnykh retseptorov golovnogo mozga krysy i cheloveka.

The kinetics of [3H]-L-glutamate binding to brain synaptic membranes (SM) and to glutamate-binding proteins (GBP) was determined with agonist and monoclonal antibodies (MAbs). It was revealed, that rat and human brain GBP have individual protein components with M(r) from 14 to 92 kDa. Quisqualate inhibited [3H]-L-glutamate binding to solubilized and to purified 68 kDa protein component. MAbs have the most activity, and NMDA was failure. It has been shown that 68 kDa component antigen determinants are similar to those of bovine, frog and rat brain synaptic membranes. Anti-GBP monoclonal antibodies blocked functional non-NMDA receptors in isolated frog spinal cord. Immunocytochemistry was done on rat and human brain sections. Distribution of quisqualate receptors was determined with light and electron microscopy. Some properties of vertebrate CNS non-NMDA receptors are discussed.

[Role and place of biochemical markers in diagnosis of cerebral ischemic stroke].

In recent years neurologists pay special attention to biochemical markers of instrumental diagnosis of brain ischemia in its acute phase. Determination of specific biomarkers in the blood of patients at early stages of cerebral blood circulation disorders may be helpful in screening patients at high risk of stroke in the short-term period. We present a review of literature and an analysis of own data (over 200 patients) with chronic and acute cerebral blood circulation disorders on the possibility of using brain biomarkers in clinical practice. The diagnostic value of NR2-antibodies in stroke with ischemic volume 5-70 cm3 is approximately 95,9% and in transitory ischemic attacks--98%.