Marija Slavić

Hydrogen peroxide affects contractile activity and anti‐oxidant enzymes in rat uterus

Background and purpose:  The effects of hydrogen peroxide (H2O2) on uterine smooth muscle are not well studied. We have investigated the effect and the mechanism of action of exogenous hydrogen peroxide on rat uteri contractile activity [spontaneous and calcium ion (Ca2+)‐induced] and the effect of such treatment on anti‐oxidative enzyme activities.

Effects of subacute oral warfarin administration on peripheral blood granulocytes in rats.

Warfarin affects mainly vitamin K dependent (VKD) processes, but the effects on some non-VKD-related activities such as tumor growth inhibition and mononuclear cell-mediated immune reactions were shown as well. In this study, the effect of subchronic (30 days) oral warfarin (0.35 mg/l and 3.5mg/l) intake on peripheral blood granulocytes in rats was investigated. Increase in prothrombin and partial thromboplastin time at high warfarin dose reflected its basic activity. Priming effect for respiratory burst was noted at both warfarin doses, while only high warfarin dose resulted in priming for adhesion, the rise in intracellular myeloperoxidase content/release and stimulation of nitric oxide production. Differential effects of high warfarin dose were noted on granulocyte cytokines IL-6 (lack of the effect), TNF-α (decreased release and mRNA expression) and IL-12 (increase in mRNA for IL-12 subunits p35 and p40). Changes in granulocytes seems not to rely on mitogen activated kinases p38 and ERK. Warfarin intake was associated with an increase in circulating IL-6, fibrinogen and haptoglobin and with changes in the activity of erythrocyte antioxidant enzymes superoxide dismutase and catalase. The effects of oral warfarin intake on peripheral blood granulocytes demonstrated in this study might be relevant for oral anticoagulant therapy strategies in humans.

Comparison of the effects of methanethiol and sodium sulphide on uterine contractile activity

BACKGROUND Our aim was to investigate the effect of methanethiol (CH3SH) on contractility of rat uterus and activities of redox-active enzymes, and to compare them with the effect of sodium sulphide (Na2S), a hydrogen sulphide (H2S/HS(-)) donor. METHODS Uteri were isolated from virgin Wistar rats, divided into six groups, controls (untreated uteri allowed to contract spontaneously and in the presence of Ca(2+)(6mM)), CH3SH treated (spontaneously active and Ca(2+) induced) and Na2S treated (spontaneously active and Ca(2+) induced). Underlying antioxidative enzyme activities (superoxide dismutase--SOD, glutathione peroxidase--GSHPx, glutathione reductase--GR) in CH3SH- or Na2S-treated uteri were compared to controls. RESULTS Our experiments showed that CH3SH and Na2S provoked reversible relaxation of both spontaneous and Ca(2+)-induced uterine contractions. The dose-response curves differed in shape, and CH3SH curve was shifted to higher concentration compared to H2S/HS(-). The effects of Na2S fitted sigmoid curve, whereas those of CH3SH fitted linearly. CH3SH provoked increased SOD activity and decreased GR activity. However, Na2S (H2S/HS(-)) provoked an increase in SOD activity exclusively in Ca(2+)-stimulated uteri, while the activity of GSHPx was increased in both types of active uteri. CONCLUSION Our results imply that CH3SH may have a constructive role in the control of muscle function and metabolism. Observed differences between CH3SH and H2S/HS(-) could be attributed to a larger moiety that is present in CH3SH compared to H2S, but they are more likely to be a consequence of the specific actions of HS(-), in relation to its negative charge.

Induction of energy metabolism related enzymes in yeast Saccharomyces cerevisiae exposed to ibogaine is adaptation to acute decrease in ATP energy pool

Ibogaine has been extensively studied in the last decades in relation to its anti-addictive properties that have been repeatedly reported as being addiction interruptive and craving eliminative. In our previous study we have already demonstrated induction of energy related enzymes in rat brains treated with ibogaine at a dose of 20mg/kg i.p. 24 and 72 h prior to proteomic analysis. In this study a model organism yeast Saccharomyces cerevisiae was cultivated with ibogaine in a concentration of 1mg/l. Energy metabolism cluster enzymes glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, enolase and alcohol dehydrogenase were induced after 5h of exposure. This is a compensation of demonstrated ATP pool decrease after ibogaine. Yeast in a stationary growth phase is an accepted model for studies of housekeeping metabolism of eukaryotes, including humans. Study showed that ibogaines influence on metabolism is neither species nor tissue specific. Effect is not mediated by binding of ibogaine to receptors, as previously described in literature since they are lacking in this model.

Effect of indometacin pretreatment on protamine sulfate-mediated relaxation of the isolated rat uterus: the role of the antioxidative defense system

Previous results in this laboratory indicate that protamine sulfate (PS) evokes dose-dependent relaxation of both spontaneous and calcium ion-induced uterus activity mediated predominantly by potassium channels and, to a small extent, via β-adrenergic receptors or nitric oxide (NO)-dependent pathways. Indometacin is a nonselective inhibitor of cyclooxygenase (COX 1 and COX 2) that has the ability to delay premature labor by reducing uterine contractions through the inhibition of prostanglandin synthesis in the uterus. This study investigates the effects of indometacin (0.1 and 1 μg/ml) pretreatment on the PS-induced relaxation of isolated uterine smooth muscle. Indometacin pretreatment per se did not change the activity of the uteri. However, indometacin significantly increased PS-induced relaxation of spontaneous uterine contractions. Indometacin pretreatment significantly decreased the magnitude and slope of PS-induced relaxation of calcium ion-induced uterine contractions. Indometacin pretreatment increased CuZnSOD activity and slightly increased GR activity during spontaneous uterine contractions when compared to PS alone. In calcium ion-induced contractions, indometacin pretreatment increased CuZnSOD, GSH-Px and GR activities. These results suggest that, in addition to its COX inhibitory effects, indometacin influences the effects of PS. Therefore, it is possible that indometacin regulates diverse cell functions via its association with lipid membranes by altering micro-environments within the membranes. The above-mentioned processes appear to be partly mediated by redox processes involving ROS, lipid peroxides and antioxidant enzymes. The extent of the PS-mediated effect as different in spontaneous versus calcium ion-induced active uteri.

The mechanisms responsible for neuroprotective capacity of arylpiperazine dopaminergic ligands against cell death induced by sodium nitroprusside

A group of sixteen arylpiperazines had been previously synthesized and evaluated for atypical antipsychotic activity. Here we examined these compounds for their neuroprotective capacity. The affinity and agonist/antagonist action of the arylpiperazines at dopamine hD(2S) receptors were determined in vitro on membranes from stably transfected CHO-hD(2S) cell line. The assays for cell viability and antioxidative capacity (total glutathione and total superoxide dismutase activity), amount of nitric oxide and superoxide radicals, as well as influence on prosurvival pathways (Akt and ERK), were performed on the human neuroblastoma cell line SH-SY5Y. Cell death was induced by oxidative or nitrosative stress, or by growing cells in the medium deprived of serum. Only four of the arylpiperazines exhibited notable neuroprotection against cell death induced by sodium nitroprusside. Two of these arylpiperazines induced elevations of pAkt, while two other compounds reduced the levels of pErk, whereas these actions are considered to support the cell survival. The benzimidazole heteroaryl-group, that mimics catechol moiety of the dopamine molecule, might be the prerequisite structure for the neuroprotective action of these ligands. It is postulated that neuroprotection was acquired also by elevation of endogenous glutathione or total superoxide dismutase activity.

Ex vivo effects of ibogaine on the activity of antioxidative enzymes in human erythrocytes.

ETHNOPHARMACOLOGICAL RELEVANCE Ibogaine is a naturally occurring alkaloid with psychotropic and metabotropic effects, derived from the bark of the root of the West African Tabernanthe iboga plant. The tribes of Kongo basin have been using iboga as a stimulant, for medicinal purposes, and in rite of passage ceremonies, for centuries. Besides, it has been found that this drug has anti-addictive effects. AIM OF THE STUDY Previous studies have demonstrated that ibogaine changed the quantity of ATP and energy related enzymes as well as the activity of antioxidant enzymes in cells thus altering redox equilibrium in a time manner. In this work, the mechanism of its action was further studied by measuring the effects of ibogaine in human erythrocytes in vitro on ATP liberation, membrane fluidity and antioxidant enzymes activity. MATERIALS AND METHODS Heparinized human blood samples were incubated with ibogaine (10 and 20 μM) at 37°C for 1h. Blood plasma was separated by centrifugation and the levels of ATP and uric acid were measured 10 min after the addition of ibogaine using standard kits. The activity of copper-zinc superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were measured in erythrocytes after incubation period. The stability of SOD1 activity was further tested through in vitro incubation with H2O2 and scanning of its electrophoretic profiles. Membrane fluidity was determined using an electron paramagnetic resonance spin-labelling method. RESULTS Results showed that ibogaine treatment of erythrocytes in vitro increased ATP concentration in the blood plasma without changes in neither erythrocytes membrane fluidity nor uric acid concentration. Ibogaine also increased SOD1 activity in erythrocytes at both doses applied here. Treatment with 20 μM also elevated GR activity after in vitro incubation at 37°C. Electrophoretic profiles revealed that incubation with ibogaine mitigates H2O2 mediated suppression of SOD1 activity. CONCLUSION Some of the effects of ibogaine seem to be mediated through its influence on energy metabolism, redox active processes and the effects of discrete fluctuations of individual reactive oxygen species on different levels of enzyme activities. Overall, ibogaine acts as a pro-antioxidant by increasing activity of antioxidative enzymes and as an adaptagene in oxidative distress.

Chloride channels mediate sodium sulphide‐induced relaxation in rat uteri

Hydrogen sulphide reduces uterine contractility and is of potential interest as a treatment for uterine disorders. The aim of this study was to explore the mechanism of sodium sulphide (Na2S)‐induced relaxation of rat uterus, investigate the importance of redox effects and ion channel‐mediated mechanisms, and any interactions between these two mechanisms.

The Effects of Human Wild-Type and Fals Mutant L144P SOD1 on Non-Vascular Smooth Muscle Contractions / EFEKTI HUMANE NORMALNE I FALS MUTIRANE L144P SOD1 NA NEVASKULARNE KONTRAKCIJE GLATKIH MIŠIĆA

Summary Background: Mutated copper, zinc-containing superoxide dismutase (SOD1) may self-aggregate, an event that could also be an initial cause of motor neuron malfunction leading to disease onset. The effects of human mutated SOD1 pro- tein from the blood of familial amyotrophic lateral sclerosis (FALS) patients bearing Leu144Phe (L144F) mutation were compared to wild-type (WT) human SOD1 derived from healthy examinees, for enzymatic activity and the effects on isometric contractions of non-vascular smooth muscle. Methods: We isolated WT and L144F SOD1 enzymes from eight patients with FALS, L144F mutation in exon 5 and eight healthy controls. We then investigated SOD1 activities in the obtained samples by the adrenaline method and pro- filed them electrophoretically. Finally, we applied WT and L144F SOD1 on the isolated rat uterus. Results: L144F SOD1 showed lower superoxide-dismutating activity compared to WT human SOD1. We found that, in contrast to WT human SOD1, mutated L144F does not induce smooth muscle relaxation. Conclusions: Our data suggest that the lack of relaxation of muscle tonus in the presence of mutated SOD1 may have pathogenic feedback effects in FALS. Kratak sadržaj Uvod: Mutirana bakar, cink superoksid-dizmutaza (SOD1) može da pravi agregate, što predstavlja početni uzrok ošte- ćenja motornog neurona može da izazove nastanak bolesti. U ovom radu su pokazani efekti humane bakar, cink super- oksid dizmutaze iz krvi pacijenata obolelih od familijarne amiotrofične lat|eralne skleroze (FALS) sa Leu144Phe (L144F) mutacijom i normalne (wild-type - WT) humane SOD1, iz krvi zdravih kontrola, na glatkom mišiču. Metode: Izolovali smo WT i L144F SOD1 enzime kod osam odabranih FALS pacijenata sa L144F mutacijom na egzonu 5 i pet zdravih kontrola. Dalje smo ispitivali aktivnost SOD1 u dobijenim uzorcima adrenalinskom metodom i elektro- foretski ih profilisali. Konačno, izolovanú WT i L144F SOD1 aplicirali smo na izolovaní uterus pacova. Rezultati: Aktivnost L144F SOD1 je statistički značajno manja (p<0,05) u poredenju sa aktivnosti WT SOD1 zdra- vih kontrola. L144F ne izaziva relaksaciju glatkog mišica, kao što je to slučaj sa WT SOD1. Zaključak: Naši rezultati pokazuju da izostanak relaksacije mišičnog tonusa u prisustvu mutirane SOD1 može imati štetni povratni efekat kod FALS pacijenata.

Tianeptine's effects on spontaneous and Ca2+-induced uterine smooth muscle contraction.

Tianeptine is a novel anti-depressant with an efficacy equivalent to that of classical anti-depressants. Additional beneficial effects include neuroprotection, anti-stress and anti-ulcer properties whose molecular mechanisms are still not completely understood but may involve changes in the anti-oxidant defence system. Herein, we have studied the effects of tianeptine on both contractile activity of isolated rat uteri and components of the endogenous anti-oxidative defence system. Tianeptine-induced dose-dependent inhibition of both spontaneous and Ca2+-induced contraction of uterine smooth muscle. The effect was more pronounced in the latter. Tianeptine treatment increased glutathione peroxidase (GSH-Px) and catalase (CAT) activities in spontaneous and Ca2+-stimulated uteri. A significant decrease in glutathione-reductase (GR) activity in both spontaneous and Ca2+-induced uterine contractions after tianeptine treatment indicated a reduction in reduced glutathione and consequently a shift toward a more oxidised state in the treated uteri. In spontaneously contracting uteri, tianeptine caused a decrease in copper-zinc SOD (CuZnSOD) activity. Tianeptines anti-depressant effects may be accomplished by triggering a cascade of cellular adaptations including inhibition of smooth muscle contractility and an adequate anti-oxidative protection response.