[Influence of poly(ADP-ribose) polymerase inhibitors on some parameters of oxidative stress in blood leukocytes of rats with experimental diabetes].

The study was undertaken to investigate the influence of specific inhibitors of poly(ADP-ribose)polymerase-1 (PARP-1), in particular nicotinamide and 1,5-isoqinolinediol on white blood cells of rats with diabetes. Using the fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate ROS production in leukocytes was asseced. It was found that the development of streptozotocin-induced diabetes was accompanied by an intensification of oxidative stress and a significant decrease in viability of blood leukocytes as compared to control animals. Administration of PARP-1 inhibitors prevented the development of oxidative stress in leukocytes and increased their viability. It was shown a reduction of superoxide dismutase activity in serum in diabetes. Investigated PARP-1 inhibitors had no effect on the activity of superoxide dismutase and glucose levels in the blood. The findings suggest the intensification of oxidative stress in leukocytes of diabetic animals and the ability of nicotinamide and 1,5-isoqinolinediol to prevent its development depending on the features of their structure.

[Oxidative stress in blood leukocytes, pro/antioxidant status and fatty acids composition of pancreas lipids at experimental acute pancreatitis in rats].

In an experimental model of acute pancreatitis (AP) in rats no alteration in leukocyte's viability was found by flow cytometry as compared to control. After 1 day of AP production of reactive oxygen forms in granulocytes was increased more than 5 times, but after 3 days their level was decreased. Alterations of pro/antioxidant status and specific changes in the fatty acid composition in the pancreas were established. With the development of AP, the processes of lipids peroxidation were intensified while antioxidant system was altered, that was evidenced by inflammation in the pancreas. In these conditions, the increase of phospholipase A2 activity was accompanied by significant changes of fatty acid composition of the total lipids in the pancreas. This increased relative total content of saturated fatty acids, in particular myristic, palmitic and stearic acid increased, while the total content of polyunsaturated essential fatty acids omega-3 (linolenic, eicosapentaenoic, dokozapentayenoic, docosahexaenoic) decreased. The preparation containing omega-3 polyunsaturated fatty acids partially normalized the lipid and fatty acids composition as well as prooxidant-antioxidant system.

[Nicotinamide influence on pancreatic cells viability].

The study was undertaken to investigate the modulating effect of nicotinamide (NAm) in different concentrations and under different glucose concentrations on the viability and oxidative stress induced by streptozotocin (STZ, 5 mmol/l) and hydrogen peroxide (H2O2, 100 micromol/l) on isolated rat pancreatic cells of the Langerhans islets in vitro. Cell viability did not depend on the concentration of glucose in the range of 5-20 mmol/l, and in subsequent studies we used glucose in concentration of 10 mmol/l to protect cells against its hypo- and hyperglycemic action. Cytoprotective effect of NAm in concentrations from 5 to 20 mmol/l on cells survival was the same. It was found that the destructive action of STZ and H2O2 during 24 hours on isolated cells of the pancreas resulted in the significant cell death. It was revealed that NAm in concentration of 5 mmol/l not only had cytoprotective effects against STZ and H2O2 but also partially reduced the level of oxidative stress in the investigated cells induced by these compounds. High concentration of NAm, 35 mmol/l, causes cytotoxic effect on the viability of pancreatic islet cells and increase of oxidative stress induced by STZ and H2O2. Most likely these effects could be associated with direct modulatory action of NAm on important effector mechanisms involved in cell death, including PARP-dependent processes, or/and indirectly, through metabolic and antioxidant effects of the compound.

[Efficacy of immunoadsorbent treatment in experimental allergic encephalomyelitis].

Hemoperfusion through the granulated hemoadsorbent SCN, fibrous carbonic adsorbent AUVM and immunoadsorbent (SCN with immobilized MBP) was applied for the treatment of experimental allergic encephalomyelitis (EAE) in guinea pigs. EAE was induced by single subcutaneous injection of 100 microg of MBP in complete Freund's adjuvant. Hemoperfusion was performed on the stage of EAE manifestation or in latent period. It was found that immunoadsorbent has the highest therapeutic efficacy and allows to eliminate up to 32% anti-MBP antibodies from the serum of guinea pigs with EAE, has up to 84% and 90% of adsorptive capacity of small and middle weight endogenous substances, respectively, and reduces the level of metabolites with molecular weight less than 30 kDa in blood plasma up to 36%.

[Noncoenzyme function of vitamin PP and its biologically active derivatives: the current state of the problem].

This review is devoted to the current state of investigations of vitamin PP and nicotinamide dinucleotides noncoenzyme functions. Particular attention has been focused on the role of these compounds in post-translation modification of proteins (mono- and poly-ADP-ribosylation), in regulation of gene activity, calcium homeostasis and Ca2+ signalling as well as in modulation of synaptic transmission. Biological significance of these processes in cell function was elicited. The role of deregulation of vitamin PP mediated signalling mechanisms involved in control over the cell function under conditions of different diseases was emphasized.

[Mechanisms of diabetes-induced impairements of serotonin release from rat brain synaptosomes: effect of nicotinamide].

It has been previously shown that diabetes-associated central nervous system abnormalities are characterized by progressive alterations of neurotransmission. In particular, recent studies from our group have demonstrated that more early diabetes is accompanied by the increased spontaneous serotonin release from isolated synaptic endings; however the mechanism is still not clear. The current study was undertaken to estimate the relative importance of membrane potential and extracellular Ca2+ in the serotonin secretion process in diabetes. With the premise that increased phosphorylation of target proteins may be responsible for the increase in transmitter release we tested whether cAMP/PKA-mediated phosphorylations as well as mono-ADP-ribosylation of effector proteins were implicated in diabetes-associated brain failures. In addition, the effects of nicotinamide, a multiple-action compound, were examined. It was shown that diabetes caused a significant increase in spontaneous release of [2-(14)C]serotonin that was accompanied by synaptic membranes depolarization. Omission of Ca2+ from the incubation medium largely inhibited serotonin release only in untreated diabetes. Exposure of diabetic synaptosomes to cAMP-dependent protein kinase inhibitor H89, similar to Ca2+ -free medium, downregulated serotonin release. The level of constitutively mono-ADP-ribosylated proteins of diabetic synaptosomes was elevated vs control. Protein mono-ADP-ribosylation induced by cholera toxin (CTX), activator of Gs-protein-coupled adenylyl cyclase, resulted in excessive 1.2-fold enhancement over basal level but to the less extent in diabetes as compared with that of control. Nevertheless, CTX as well as forskolin exerted more strong stimulating effect on serotonin release from diabetic synaptosomes as compared to control. H89 counteracted CTX-related action on this variable strongly suggesting that impaired serotonin release is, at least, dependent on Gs-protein-mediated phosphorylation. Nicotinamide treatment virtually normalized both protein mono-ADP-ribosylation and serotonin release as well as synaptosomal response to all stimuli used. The data suggest that alterations in protein mono-ADP-ribosylation may be involved as a possible mechanism responsible for the impaired neurotransmission in diabetes and nicotinamide may efficiently protect against ADP-ribosylationmediated abnormalities in brain function.

[Effect of nicotinamide on the reactions of peroxide oxidation of biomolecules in the rat brain and erythrocytes in 1,2-dichloroethane toxic injury].

It was established that acute poisoning of rats by 1,2-dichloroethane induced considerable changes in lipid peroxidation indices, glutathione content and activity of antioxidant enzymes--superoxidase, catalase, glutathione peroxidase in the brain tissue, erythrocytes and blood plasma. It was shown that nicotinamide in the dose of 200 mg/kg prevented considerable degree of the intoxication caused by 1,2-dichloroethane as well as activation of lipid peroxidation and inhibition of antioxidant defens enzyme activities in tissue of experimental animals.

[Na+, K+-ATPase activity and serotonin transport in the rat brain synaptosomes fractions after acute 1,2-dichloroethane intoxication and nicotinamide administration]. / Na+, K+-ATR-azna aktyvnist' ta transportuvannia serotoninu u fraktsiï synaptosom holovnoho mozku shchuriv za hostroï intoksykatsiï 1,2-dykhloretanom ta vvedennia nikotynamidu.

Alterations of Na+,K+-ATPase activity and serotoninergic system functioning were investigated in brain synaptosomes fractions of rats under experimental acute 1,2-dichloroethane (DChE) intoxication. It was shown that Na+,K+-ATPase activity was markedly increased (by 41,8%) in a period of 24 h after DChE intoxication and decreased (by 27%) after 48 h intoxication. The level of [2-14C]-serotonin uptake by synaptosomes was progressively diminished after 24 and 48 h after DChE injection whereas the activity of monoamine uptake proved to be unchanged. Nicotinamide (200 mg/kg of body weight) was administered to rats subjected to DChE 1, 24 and 36 h after poisoning. The treatment of rats with nicotinamide resulted in some normalization of brain synaptosomal Na+, K+-ATPase activity and serotonin uptake controlled at 48 h after DChE intoxication.

[Rostyslav Vsevolodovych Chahovets'. Creative activity and scientific school (on the 100th anniversary of birthday)]. / Rostyslav Vsevolodovych Chahovets'. Tvorchyi shliakh ta naukova shkola (do 100-richchia vid dnia narodzhennia).

Herein we review the main stages of life and scientific work of Rostislav Vsevolodovich Chagovets, prominent biochemist and vitaminologist, Member of the Academy of Sciences of Ukrainian SSR, professor and talanted pedagogue. As a founder of scientific school of vitaminologists and researcher in the field of muscle biochemistry, nutrition and vitamins he made a valuable contribution to development of the national and world biochemistry. This work reflects the main trends of fundamental scientific investigations and developments of vitaminological school founded by R. V. Chagovets which underlied the development of contemporary practical vitaminology.

[State of GABA-benzodiazepine receptor complex in diabetic neuropathy: effect of nicotinamide and nicotinoyl-GABA]. / Stan HAMK-benzodiazepinovoho retseptornoho kompleksu za diabetychnoï neiropatiï: efekt nikotynamidu ta nikotynoïl-HAMK.

An increase in GABA uptake by isolated rat brain synaptic endings as well as a decrease of pharmacologically active GABA analogue muscimol specific binding have indicated a physiologically drastic failure in realization of GABA-mediated inhibitory effects in CNS induced by diabetic encephalopathy. In spite of the impairment of inhibitory function of GABAergic transmission in diabetes a crucial activation of benzodiazepine receptors was determined, as it is tested by the increase in specific binding of flunitrazepam by synaptic membranes. This increase may play an important role in endogenous control of neural activity associated with the factors undefined so far. Using the approach that GABA, and several synthetic GABA agonists, appear to increase the affinity of the benzodiazepine recognition sites for such ligands, presumably by some allosteric mechanism, the findings concerning the in vitro binding assay technique confirm at least some of the functional characteristics observed between GABA and benzodiazepine receptors in vivo under pathological conditions. Indeed, the absence of activating effect on the affinity of flunitrazepam specific binding in the presence of micromolar concentrations of exogenous GABA implicate diabetes-induced alterations in coupling GABA- and benzodiazepine receptors that might be linked to changes in conformantial state of this membrane-bound complex and could partially explain diabetes-induced impairments of GABAergic transmission evaluated in the present study. Our study suggests that nicotinamide and especially GABA play an important role in improving the functioning of brain GABA-benzodiazepine complex impaired in diabetes through specific ligand-mediated mechanism and can be useful in the management of diabetes-associated brain failures.

[Correction by nicotinamide and nicotinoyl-GABA of dopamine metabolism in rat brain in experimental Parkinson's disease]. / Korektsiia nikotynamidom ta nikotynoïl-HAMK obminu dofaminu v holovnomu mozku shchuriv za eksperymental'noho parkinsonizmu.

It was established, that serotonin and dopamine content and dopamine uptake by brain nerve endings under experimental parkinsonism are decreased. Nicotinamide nicotinoyl-GABA administration leads to normalization these parameters. It was shown that NAm was more effective on serotonin content while nicotinoyl-GABA on dopamine one. Dopamine uptake was impaired at experimental parkinsonism and partially was normalized by incubation with NAD (10(-6) M). Thus, NAm, nicotinoyl-GABA and NAD are involved in the regulation of brain neurotransmission under experimental parkinsonism and can be useful in treatment of Parkinson's disease.

[Diabetic neuropathies. Metabolism of sorbitol in sciatic nerve tissue in streptozotocin diabetes]. / Diabetychna neiropatiia. Metabolizm sorbitolu u tkanyni sidnychnoho nerva za streptozototsynovoho diabetu.

The increase of sorbitol and fructose levels caused by aldose reductase activation and sorbitol dehydrogenase inhibition were observed in sciatic nerve of streptozotocin-diabetic rats. Elevated polyol pathway activity has been implicated in the development of diabetic complications such as neuropathy. The regulation of polyol pathway enzymes is based on the changes of redox state of free nicotinamide nucleotides. The decrease of the NADP+/NADPH ratio in cytosolic compartment of sciatic nerve cells activated aldose reductase and the decrease of the NAD+/NADH ratio inhibited sorbitol dehydrogenase. Nicotinamide as a precursor of NAD+ biosynthesis increased the free NADP+/NADPH and NAD+/NADH ratios and inhibited the activity of polyol pathway. The sorbitol level decreased in sciatic nerve of nicotinamide-treated streptozotocin-diabetic rats as compared to non-treated ones. Thus, the data provide evidence for important role of nicotinamide, as an antidiabetic drug, in prevention or correction of diabetic neuropathy.

[Neurotrophic action of nicotinamide and nicotinoyl-GABA in rat brain in experimental Parkinsonism]. / Neirotropna diia nikotynamidu ta nikotynoïl-gamma-aminomaslianoï kysloty u holovnomu mozku pry eksperymental'nomu Parkinsonizmi shchuriv.

It was established, that the content of nicotinamide adenine dinucleotides and the binding of NAD by isolated brain cortex synaptic membranes under experimental parkinsonism are impaired. Treatment of the experimental results in the Scatchard plots for binding of [U-14C]NAD to the brain cortex synaptic membranes demonstrated that binding capacities lowered, without changes of affinities. NAD-glycohydrolase involved in development of this pathology. The modulative effect of in vivo administered NAm and nicotinoyl-GABA supposes that NAm acts via NAD which binds specifically with synaptic membranes. Thus, NAm and nicotinoyl-GABA are involved in the regulation of the processes in the brain under experimental parkinsonism.

[Stimulation of gluconeogenesis with 1,3-butanediol in the perfused rat liver]. / Stimuliatsiia gliukoneogenezu 1,3-butandiolom u perfuzovanii pechintsi shchuriv.

An intensified synthesis of glucose is observed in gluconeogenesis from endogenous precursor only for the first 30 min of perfusion. Pyruvate introduction into the medium raises phosphoenolpyruvate carboxykinase and fructose-1,6-diphosphatase activities in the liver and determines maintenance of the glucose formation high rate for 90 min of perfusion. 1,3-butanediol is found to have a stimulating effect on gluconeogenesis from pyruvate. Introduction of 1,3 bytanediol into perfusate decreases the redox state of free NAD-pairs, increases the content of phosphoenolpyruvate, malate. ATP and the phosphoenolpyruvate carboxykinase and fructose-1.6-diphosphatase activity in the perfused liver.