A novel carboxymethylated mercaptotriazinoindole inhibitor of aldose reductase interferes with the polyol pathway in streptozotocin-induced diabetic rats.

The aim of the present work was to study the effect of 3-mercapto-5H-1,2,4-triazino[5,6-b]indole-5-acetic acid (CMTI), an efficient aldose reductase inhibitor, on sorbitol accumulation in selected organs of streptozotocin-induced diabetic rats in vivo. In addition, the effect of CMTI on aldose reductase back reaction and on sorbitol dehydrogenase was determined. The model of experimental diabetes in male Wistar rats induced by streptozotocin was used.

Oxidative stress induced by the Fe/ascorbic acid system or model ischemia in vitro: effect of carvedilol and pyridoindole antioxidant SMe1EC2 in young and adult rat brain tissue.

New effective strategies and new highly effective neuroprotective agents are being searched for the therapy of human stroke and cerebral ischemia. The compound SMe1EC2 is a new derivative of stobadine, with enhanced antioxidant properties compared to the maternal drug. Carvedilol, a non-selective beta-blocker, possesses besides its cardioprotective and vasculoprotective properties also an antioxidant effect.

Carboxymethylated tetrahydropyridoindoles as aldose reductase inhibitors: in vitro selectivity study in intact rat erythrocytes in relation to glycolytic pathway.

Oxidative stress and polyol pathway hypotheses are generally accepted in the etiology of diabetic complications. Recently, novel carboxymethylated pyridoindoles, structural analogues of the efficient chain-breaking antioxidant stobadine, were designed, synthesised and characterised as prospective aldose reductase inhibitors endowed with antioxidant activity. Of them (2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole-8-yl)-acetic acid (compound 1) and (2-phenethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole-8-yl)-acetic acid (compound 2) were found to be the most efficient inhibitors of aldose reductase with the corresponding IC50 values in a micromolar region.

In vitro inhibition of lens aldose reductase by (2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole-8-yl)-acetic acid in enzyme preparations isolated from diabetic rats.

(2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole-8-yl)-acetic acid (compound 1), a novel aldose reductase inhibitor, was assayed for efficacy and selectivity to inhibit rat lens aldose reductase under in vitro conditions by using enzyme preparations obtained from diabetic animals. The inhibitory efficiency was characterized by IC(50) in micromolar region. Enzyme kinetics analysis revealed uncompetitive type of inhibition, both in relation to the D,L-glyceraldehyde substrate and to the NADPH cofactor.

Acute toxicity of magnetic nanoparticles in mice.

Objectives: The acute toxicity of magnetic nanoparticles was effectively lowered by their encapsulation with poly(D,L lactide). In relation to the idea to use magnetic nanoparticles in development of new delivery systems suitable for targeted drug administration, the toxicological profile of five types of magnetic fluids was assessed in mice.

Methods: The nanoprecipitation method was used to prepare magnetic fluids containing nanoparticles of Fe(3)O(4) encapsulated with biodegradable substances.

Testing of bacteria isolated from HIV/AIDS patients in experimental models.

Objectives: Bacteria purified from the intestinal tract of HIV/AIDS patients were tested for the capacity to be internalised by cells of the HL-60 cell line. Secondly, the bacteria have been applied to the rabbit's colon in order to test their pathogenic ability.

Results: The ability of the bacteria to be internalised by HL-60 cells was found to be very expressive.

Temporal relationship between lens protein oxidation and cataract development in streptozotocin-induced diabetic rats.

We compared the progression of lens opacification with the time course of oxidation of lens proteins under conditions of streptozotocin-induced experimental diabetes in rats. By the end of the 17th week, approx. 50% of the diabetic animals developed mature cataracts.

Effect of the pyridoindole antioxidant stobadine on development of experimental diabetic cataract and on lens protein oxidation in rats: comparison with vitamin E and BHT.

Purpose: The aim of this study was to investigate the effect of dietary supplementation with the pyridoindole antioxidant stobadine on the development of diabetic cataract in rats. The findings were compared with the effect of the natural antioxidant vitamin E and the well known phenolic synthetic antioxidant butylated hydroxytoluene.

Methods: Streptozotocin induced diabetic male Wistars rats were fed for 18 weeks a standard diet or a diet supplemented with stobadine (0.

Pentose phosphate pathway, glutathione-dependent enzymes and antioxidant defense during oxidative stress in diabetic rodent brain and peripheral organs: effects of stobadine and vitamin E.

The aim of the present study was to investigate the effects of treatment with antioxidant stobadine (ST) on the activities of enzymes related with pentose phosphate pathway and glutathione-dependent metabolism and the other markers of oxidative stress in brain and peripheral organs of diabetic rats, and to compare the effects of ST treatment alone with the effects of treatments with another antioxidant vitamin E and ST plus vitamin E. Rats were made diabetic by the injection of streptozotocin (STZ; 55 mg/kg IP), and, 2 days later, some control and diabetic rats were left untreated or treated with ST (24.7 mg/kg/day, orally), vitamin E (400-500 U/kg/day, orally), or both substances together.

The pyridoindole antioxidant stobadine attenuates albuminuria, enzymuria, kidney lipid peroxidation and matrix collagen cross-linking in streptozotocin-induced diabetic rats.

The aim of the present study was to investigate the effect of dietary supplementation with the pyridoindole antioxidant stobadine on kidney status and function in streptozotocin-induced diabetic rats. Diabetic male Wistar rats were fed a standard diet for 32 weeks or a diet supplemented with stobadine (0.05% w/w).

The pyridoindole antioxidant stobadine attenuates histochemical changes in kidney of streptozotocin-induced diabetic rats.

The aim of the present study was to investigate the effects of dietary supplementation with the pyridoindole antioxidant stobadine on histochemical parameters in kidney of streptozotocin-induced diabetic rats. Diabetic male Wistar rats were fed a standard diet or a diet supplemented with stobadine (0.05% w/w) for 24 weeks.

L-arginine reduces structural remodeling in the diabetic rat myocardium.

Metabolism, monitored via in situ catalytic enzyme histochemistry and fine structure, was studied in the myocardium of chronic diabetic male Wistar rats administered L-arginine (12.8 mg/100 g/day) for 24 weeks. Diabetes was induced with a single i.

Dietary supplementation of the pyridoindole antioxidant stobadine reduces vascular impairment in streptozotocin-diabetic rats.

We studied the influence of hyperglycemia lasting 1, 4, 6 and 8 months on the reactivity and ultrastructure of the aorta in Wistar rats. Moreover, the effect of the pyridoindole antioxidant stobadine ((-)-cis-2,8-dimethyl-2,3,4,4a,5,9b-hexahydro-1H-pyrido[4,3-b]indole) on the changes induced by the 8-month hyperglycemia were studied. Hyperglycemia was induced by streptozotocin (STZ, 55 mg/kg i.

Placental transfer of the antioxidant stobadine at different gestational stages in rabbits.

The distribution of [3H]-stobadine, a pyridoindole antioxidant, was investigated in New Zealand white rabbits and their fetuses on days 20 and 27 of gestation. The concentrations of [3H]-stobadine were determined in maternal and fetal organs after oral administration in a single dose of 5.0 mg/kg.

Effect of dietary supplementation with the pyridoindole antioxidant stobadine on antioxidant state and ultrastructure of diabetic rat myocardium.

Consistent with the postulated role of oxidative stress in the etiology of late diabetic complications, pharmacological interventions based on biological antioxidants have been suggested. The aim of the present study was to investigate the effect of dietary supplementation with the pyridoindole antioxidant stobadine on the myocardial antioxidant status and ultrastructure of streptozotocin-diabetic rats. Diabetic male Wistar rats were fed for 32 weeks a standard diet or a diet supplemented with stobadine (0.

p-Dimethylaminobenzaldehyde-reactive substances in tail tendon collagen of streptozotocin-diabetic rats: temporal relation to biomechanical properties and advanced glycation endproduct (AGE)-related fluorescence.

In the present work, pepsin digests of tail tendons from streptozotocin-diabetic rats were found to contain material that reacted rapidly at room temperature with p-dimethylaminobenzaldehyde (Ehrlich's reagent) to give an adduct with an absorbance spectrum characteristic of the Ehrlich chromogen of pyrrolic nature determined in ageing collagens. A significant correlation of the Ehrlich adduct with tendon mechanical strength and collagen fluorescence characteristic of advanced glycation endproducts was observed. Collagen content of the Ehrlich-positive material was found to be significantly elevated in tendons of diabetic rats compared with age-matched healthy controls.

Streptozotocin diabetes-induced changes in aorta, peripheral nerves and stomach of Wistar rats.

In rats with diabetes induced by streptozotocin (STZ), we studied the reactivity of the aorta in response to vasoconstrictor and vasorelaxant agents, changes in conduction velocity in the sciatic nerve, and glutathion (GSH) content in the gastric mucosa as well as the occurrence of spontaneous gastric lesions. STZ-induced diabetes was found to be accompanied by endothelial injury, exhibited by diminished endothelium-dependent relaxation and by increased noradrenaline- and H2O2-induced contraction. Conduction velocity in the nerves from STZ-treated animals was significantly lower compared to that in nerves from control animals.

Streptozotocin-induced experimental diabetes in male Wistar rats.

The aim of the present work was to test the sensitivity of young male Wistar rats, Dobrá Voda (Dv:WI) to the diabetogenic effect of streptozotocin (STZ) with regard to their health condition and mortality rates. Eight-week-old rats, weighing from 200 to 230 g, were randomised into five groups of eight animals. Streptozotocin was administered by i.

Placental transfer of stobadine in rabbits.

Stobadine, a pyridoindole antioxidant, was investigated for its placental transfer and distribution in New Zealand white rabbits on the 27th day of gestation. The concentrations of stobadine were determined in maternal and foetal organs (plasma, brain, heart) at 30, 60, 120, and 360 minutes after oral administration of the drug in a dose of 5 mg/kg. The results obtained proved that after oral stobadine intake by rabbits at the stage of advanced pregnancy both maternal and foetal organs were under a certain drug level which could act protectively against oxidative stress--frequently occurring during late organogenesis, foetal stages and delivery, as well as during early postnatal development.

Effect of long-term administration of stobadine on exploratory behaviour and on striatal levels of dopamine and serotonin in rats and their offspring.

Stobadine (STB), a cardioprotective drug, was evaluated for its effect on the intensity and habituation of exploratory behaviour in open field testing and on the levels of striatal dopamine (DA), serotonin (5-HT) and their metabolites (3,4-dihydroxyphenylacetic acid, homovanillic acid, 5-hydroxyindole-3-acetic acid) in rats and their offspring. Dams were treated by oral gavage with STB (50 mg kg-1) for a total of 56 days from 14 days before mating to day 21 postpartum (pp). The first open field measurements of the dams were performed over 4 days at the beginning of the experiment, the second on days 21-24 pp and the third on days 49-52 pp (recovery period).

Effect of long-term administration of stobadine to rats on selective variables of spontaneous behaviour of their offspring.

The present study investigated the effect of long-term administration of the cardioprotective drug stobadine (STB) to dams on selective variables of spontaneous behaviour of their offspring in open field (horizontal and vertical activities, frequency and duration of grooming, and duration of total activity and immobility) tested on day 60 of age. The treatment of dams with STB significantly increased horizontal activity of offspring in both sexes. The other variables studied were not affected, with the exception of a significant increase in the frequency and duration of grooming and in the duration of total activity in females compared to males from STB treated dams.

Chronic toxicity and micronucleus assay of the new cardioprotective agent stobadine in rats.

A 26-week oral toxicity and micronucleus assays of the new cardioprotective drug stobadine (CAS 95751-51-2), in the form of dipalmitate salt (DP 1031) were performed in Wistar rats of both sexes. DP 1031 was administered daily orally in doses of 7.07, 23.

Teratogenicity of cyclophosphamide in New Zealand white rabbits.

Pregnant rabbit does received daily oral doses of 6.2 or 18.6 mg/kg cyclophosphamide (CP) on days 6-20 of gestation.

The distribution in mice of intravenously administered labelled Candida albicans.

The time dependence of the distribution of intravenously injected radiolabelled Candida albicans in the body of mice was studied. The Candida cells were labelled by cultivating them 7 days at 28 degrees C in a medium containing one of the following radionuclides: 46Sc, 95Nb, 59Fe, 144ce, 89Sr, 60Co, 65Zn, 54Mn, 45Ca, 51Cr and 91Y, which are listed in decreasing order in respect to amount bound. The labelled cells were killed by heating them 120 min at 60 degrees C, without loss of immunologic properties.

Pharmacokinetics of gentamicin administered intratracheally to rats.

The pharmacokinetics of intratracheally instilled and intravenously injected gentamicin were compared in the rat and analyzed by a one-compartment open model. The maximum concentration of gentamicin in plasma occurred within 10 min after intratracheal instillation. Considerable amounts of gentamicin were absorbed from lungs after intratracheal instillation, as shown by its concentrations in plasma and elimination in urine.