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Journal Article 2006; 27(Suppl 2): 164-167 PubMed PMID: 17159806 Citation  Keywords:  Animals, Antioxidants:pharmacology, Calcium:metabolism, Female, Flavonoids:pharmacology, Muscle, Skeletal:drug effects, Rabbits, Sarcoplasmic Reticulum Calcium-Transporting ATPases:metabolism,.   

OBJECTIVES: Effects of phenolic antioxidants, synthetized (trolox, pyridoindole stobadine) and plant extracts (EGb 761 and Pycnogenol) were investigated on the activity of Ca(2+)-ATPase from sarcoplasmic reticulum (SR) of rabbit skeletal muscle to examine their potency to modulate the activity of this calcium level regulating enzyme.r />r /> METHODS: SR vesicles and pure Ca(2+)-ATPase were isolated by ultracentrifugation. Ca(2+)-ATPase activity was measured spectrophotometrically by enzyme-coupled assay.r />r /> RESULTS: Pycnogenol (Pyc) significantly decreased the activity of Ca(2+)-ATPase incorporated into SR vesicles as well as the activity of purified Ca(2+)-ATPase, the latter with respect to both enzyme substrates, Ca(2+) and ATP. Trolox, stobadine and EGb 761 did not influence significantly the activity SR- vesicle incorporated or pure Ca(2+)-ATPase, the latter with respect to either substrate, in spite of alterations of kinetic parameters in some cases.r />r /> CONCLUSIONS: The decrease of SR Ca(2+)-ATPase activity induced by Pyc may be associated with its proapoptotic and anticancerogenic properties....

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Journal Article 2006; 27(Suppl 2): 160-163 PubMed PMID: 17159805 Citation  Keywords:  Animals, Carbazoles:pharmacology, Cells, Cultured, Immunity, Cellular:drug effects, Immunity, Innate:drug effects, Macrophages:drug effects, Mice, N-Formylmethionine Leucyl-Phenylalanine:pharmacology, Nitric Oxide Synthase Type II:metabolism, Peroxidase:m.   

OBJECTIVES: Neutrophils and macrophages are critical components of our innate host defenses. They are a potential source of nitric oxide (NO) and superoxide, known to play an important role in many physiological processes including defense, immune and inflammatory responses. Myeloperoxidase (MPO), a major NO scavenger and a marker of oxidative stress, as well as increased inducible nitric oxide synthase (iNOS) expression, may affect the NO-superoxide balance, critical for cellular redox balance in the cardiovascular system at physiologic conditions. The effect of carvedilol was studied on stimulated superoxide generation, MPO release and iNOS expression in phagocytes by using receptor operating stimuli [N-formyl-Met-Leu-Phe (FMLP), lipopolysaccharide (LPS) and specific inhibitors (wortmannin, propranolol).r />r /> METHODS: Superoxide generation was measured as superoxide dismutase inhibitable reduction of cytochrome c (550 nm), MPO activity as the oxidation of o-dianisidine in the presence of hydrogen peroxide in a spectrophotometer Hewlet Packard 8452 A (463 nm). Expression of iNOS (Western-blot analysis) in RAW 264.7 cell line (murine macrophages) was stimulated by lipopolysaccharide (LPS).r />r /> RESULTS: Carvedilol dose-dependently decreased superoxide generation and MPO release from intact neutrophils stimulated by FMLP. In the highest concentration tested, carvedilol pronounced the effect of wortmannin [inhibitor of phospholipase D (PLD) regulatory pathway] and significantly decreased LPS stimulated iNOS expression in RAW 264.7 cell line.r />r /> CONCLUSION: The conceivable cumulative non-specific membrane effect of carvedilol and its effect on PLD signalling pathway contribute to the decrease of both superoxide generation and MPO release, thus supporting the restoration of NO-superoxide balance....

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Journal Article 2006; 27(Suppl 2): 156-159 PubMed PMID: 17159804 Citation  Keywords:  Animals, Arterial Occlusive Diseases:pathology, Brain Chemistry:drug effects, Carotid Arteries, Gerbillinae, Glutathione:analysis, Ischemic Attack, Transient:pathology, Male, Malondialdehyde:analysis, Melatonin:analogs & derivatives, Protein Carbonylation.   

OBJECTIVES: To investigate whether a new derivative of melatonin, (2,3-dihydromelatonin (DHM), prevented the oxidative stress induced by ischemia /reperfusion (I/R) in the gerbil brain. To specify the effect on endogenous antioxidant activity and protein modification in the brain cortex, we evaluated the contents of glutathione (total GSx=GSH+GSSG) and protein carbonyl groups (PCG).r />r /> METHODS: Brain ischemia (I) was induced by (12 min) bilateral carotid occlusion (BCAO) in adult male gerbils (60-70 g b wt.) DHM (10 mg/kg) was administered i.p. 20 min before surgery, at the beginning of reperfusion (R), and then 2 and 6 hours later. Horizontal locomotor activity was recorded using the open-field test over the course of 24 hours. Contents of GSx and PCG were determined after 6h of reperfusion. Glutathione (GSx ) was determined spectrophotometrically using the microplate reader, lactate by the kit Randox, UK. The measurement of protein carbonyl (PCG) groups after their derivatization with 2,4-dinitrophenylhydrazine (DNPH) is the most widely used assessment of protein oxidation. The contents of PCG and malondialdehyde (MDA) were assayed spectrophotometrically.r />r /> RESULTS: Evaluation of the data obtained from horizontal locomotor activity recorded over the course of 24 hours using the open-field test showed that hyperactivity induced by I/R was returned by DHM almost to its control value during the interval of up to 6 hours (from 18,000 to 5,000 cm distance traveled, p<0.05). I/R decreased the content of GSx by 27.2% (p<0.001). Administration of DHM resulted in maintaining the content of GSx at control values (p<0.05). DHM diminished the I/R-induced increase in PCG in the cortex by 34.2% (p<0.01).r />r /> CONCLUSIONS: Our data indicate that the effect of DHM on the content of glutathione and protein carbonyl groups occurred during the first 6 hours of reperfusion. In this time interval both the content of GSx and protein carbonyl groups seem to be sensitive indicators of I/R-induced oxidative stress in the gerbil brain....

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Journal Article 2006; 27(Suppl 2): 152-155 PubMed PMID: 17159803 Citation  Keywords:  Animals, Diabetes Mellitus, Experimental:complications, Diabetic Angiopathies:pathology, Dose-Response Relationship, Drug, Intestinal Diseases:complications, Intestine, Small:blood supply, Male, Mesenteric Artery, Superior:metabolism, Phenylephrine:pharma.   

OBJECTIVES: The influence of low dose streptozotocin diabetes on intestinal and vascular injury induced by mesenteric ischaemia/reperfusion (I/R) was studied in rats. The role of reactive oxygen species (ROS) in the exacerbation of ischaemic/postischaemic damage in diabetes was addressed.r />r /> METHODS: Diabetes was induced by i.p. injection of 3 x 30 mg/kg streptozotocin and after 5 weeks male Wistar rats underwent 60 min ischaemia followed by 30 min reperfusion of the superior mesenteric artery (SMA). The extent of intestinal haemorrhagic injury was assessed macroscopically. Relaxation to acetylcholine of precontracted SMA rings was tested. Chemiluminescence (CL) enhanced by luminol of tissue samples excised from the ileum and SMA was measured.r />r /> RESULTS: In diabetic rats I/R-induced intestinal injury was significantly more pronounced compared to non-diabetic rats (63.6% potentiation). Decreased endothelial-dependent relaxation of diabetic SMA was not further influenced by I/R. Diabetes itself did not change the CL response of SMA and there was a similar CL increase in the diabetic group with I/R as in the controls. In the intestinal samples CL response was suppressed and I/R only mildly increased CL in the diabetic group.r />r /> CONCLUSIONS: Diabetes renders the intestinal tissue more vulnerable to the effects of I/R. Endothelial-dependent relaxation of diabetic SMA was not further worsened by I/R. CL responses showed a different involvement of ROS in diabetic intestinal versus vascular tissue....

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Comparative Study 2006; 27(Suppl 2): 148-151 PubMed PMID: 17159802 Citation  Keywords:  Benzothiepins:pharmacology, Histamine:pharmacology, Histamine H1 Antagonists:pharmacology, Humans, Loratadine:pharmacology, Neutrophils:drug effects, Peroxidase:metabolism, Superoxide Dismutase:metabolism, Tetradecanoylphorbol Acetate:pharmacology,.   

OBJECTIVES: To study the effect of H1-antihistamines dithiaden (Dit) and loratadine (Lor) and compare it with that of histamine (His) on phorbolmyristate acetate (PMA) stimulated chemiluminescence (CL) of whole blood, isolated neutrophils, release of myeloperoxidase (MPO), and on superoxide (SO) generation.r />r /> METHODS: Luminol- and isoluminol-enhanced CL was applied for measuring the oxidative burst, spectrophotometry was used for determination of MPO (o-dianisidine) and SO generation (superoxide dismutase inhibition of cytochrome c).r />r /> RESULTS: Dit and Lor dose-dependently inhibited CL of whole blood and significantly decreased oxidative burst both at the extra- and intracellular sites of neutrophils. Release of MPO was decreased with both drugs tested in 10-times lower concentrations than was SO inhibition. Histamine (His) was much less effective in the inhibition of the parameters investigated.r />r /> CONCLUSIONS: Histaminergic drugs of the 1st generation inhibited oxidative burst of human phagocytes in whole blood and in isolated neutrophils. The rank order of potency to inhibit CL, MPO release and SO generation in PMA stimulated phagocytes was: Dit>Lor>His....

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Comparative Study 2006; 27(Suppl 2): 144-147 PubMed PMID: 17159801 Citation  Keywords:  Acetylcholine:pharmacology, Animals, Diabetes Mellitus, Experimental:complications, Diabetic Angiopathies:complications, Evoked Potentials:drug effects, Heart:drug effects, Male, Myocardial Ischemia:complications, Rats, Rats, Wistar, Reperfusion Injury:co.   

OBJECTIVES: To investigate the effect of acetylcholine (ACh) and ischaemia/reperfusion injury on functional changes and dysrhythmias of the isolated diabetic rat heart.r />r /> METHODS AND RESULTS: On retrogradely perfused hearts isolated from 10-week-old diabetic rats (streptozotocin 30 mg/kg b.w. for three consecutive days i.p.), two types of experiments were done: /1/ The effect of acetylcholine (ACh; 3 x 10(-7) mol/l) was evaluated both during and after infusion, and /2/ the influence of the ischaemia/reperfusion injury (I/R) was studied. At the end of both experiments the hearts were electrically stimulated to evoke sustained ventricular fibrillation (VF). An increase of coronary arterial pressure, bradycardia and decreased total number of severe dysrhythmias of both types, spontaneous and evoked ones, were recorded in the diabetic hearts. ACh increased the force of contraction (LVP) and induced vasoconstriction, which persisted in the diabetic hearts even after removal of ACh from the perfusion solution.r />r /> CONCLUSIONS: The isolated diabetic rat heart was more resistant against severe dysrhythmias. After washing out the ACh, the vasoconstriction of coronary arteries still lasted, along with increased inotropic effect on the left ventricle....

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Comparative Study 2006; 27(Suppl 2): 141-143 PubMed PMID: 17159800 Citation  Keywords:  Brompheniramine:pharmacology, Chlorpheniramine:pharmacology, Extracellular Fluid:metabolism, Histamine H1 Antagonists:pharmacology, Humans, Intracellular Fluid:metabolism, Luminescence, Neutrophils:drug effects, Pheniramine:pharmacology, Reactive Oxygen S.   

BACKGROUND: Allergic inflammation was found to be accompanied by activation of neutrophils. Since this resulted in increased formation of reactive oxygen species, the antioxidative activity of antiallergic drugs was considered to decrease the risk of tissue damage. However, if the drug-induced inhibition of radical formation occurred intracellularly, it could disturb regulation of neutrophil functions and decrease bactericidal activity of these cells. Separate analysis of extra- and intracellular activity of antioxidative drugs is thus of particular importance.r />r /> OBJECTIVE: To differentiate the effects of three antiallergic H1-antihistamine drugs (pheniramine, chlor- and brompheniramine) on radical formation outside and inside human neutrophils.r />r /> METHODS: Formation of reactive oxygen species was determined in vitro using the chemiluminescence method. The chemiluminescence signal, initiated by phorbol-12-myristate-13-acetate, was enhanced either with isoluminol (extracellular) or with luminol in the presence of extracellular scavengers, superoxide dismutase and catalase (intracellular).r />r /> RESULTS: The antihistamines tested displayed dual activity - they inhibited the extracellular and potentiated the intracellular chemiluminescence. Chlor- and brompheniramine were found to be more effective than pheniramine.r />r /> CONCLUSION: Compared to other H1-antihistamines (such as dithiaden or loratadine, active both extra- and intracellularly), the observed inhibition caused by the pheniramines tested was unique since it occurred selectively outside neutrophils. This might indicate the ability of these drugs to minimise toxic effects of extracellular radicals without affecting intracellular oxidant production involved in regulation of neutrophil functions and in microbial killing....

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Clinical Trial 2006; 27(Suppl 2): 138-140 PubMed PMID: 17159799 Citation  Keywords:  Adrenergic beta-Antagonists:pharmacology, Aged, Antihypertensive Agents:therapeutic use, Antioxidants:pharmacology, Carbazoles:pharmacology, Diabetes Mellitus, Type 2:blood, Diabetic Angiopathies:blood, Female, Heart Failure:blood, Humans, In Vitro Techni.   

OBJECTIVES: In the present study we investigated whether the beta-adrenoceptor antagonist carvedilol (CARV) [Dilatrend] prevented reactive oxygen metabolite (ROM) production in human polymorphonuclear leukocytes (PMNL) or interfered with ROM already generated. To specify the site of action of CARV, we evaluated its effect on extra- and intracellular ROM generation. In addition, we studied the effect of CARV therapy on ROM production in whole blood obtained from patients with congestive heart failure (CHF) combined with type II diabetes mellitus.r />r /> METHODS: ROM generation in whole blood and isolated PMNL was determined after phorbol 12-myristate-13-acetate (PMA-0.05 micromol/l) stimulation by luminol/isoluminol-enhanced chemiluminescence (CL) in the microplate luminometer Immunotech LM-01T.r />r /> RESULTS: CARV significantly decreased CL of human whole blood in the concentrations of 10, 20, 50 and 100 micromol/l, both when applied simultaneously and after stimulation. In isolated PMNL, CARV significantly decreased extracellular CL in the concentrations of 50 and 100 micromol/l, intracellular CL was decreased in the concentrations of 20, 50 and 100 micromol/l. The nonstimulated and PMA stimulated CL of whole blood was increased in patients before therapy in comparison with healthy controls. After CARV therapy, 25 mg/day and 50 mg/day, there was a trend to reduce CL as compared to values before therapy.r />r /> CONCLUSIONS: In human PMNL, CARV interfered in vitro and ex vivo with ROM generation as well as with already generated ROM, suggestive of its both "preventive" and "therapeutic" effect....

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