Protective effect of low molecular weight heparin on oxidative injury and cellular abnormalities in adriamycin-induced cardiac and hepatic toxicity

The aim of the present work is to evaluate the effect of a heparin derivative, low molecular weight heparin (LMWH) on the biochemical changes, tissue peroxidative damage and abnormal antioxidant levels in adriamycin (ADR) induced cardiac and hepatic toxicity. Male Wistar rats (140 +/- 10 g) were divided into four groups: untreated control (group I), ADR group (a single dose intravenous injection of 7.5 mg/kg ADR--group II), LMWH control (300 microg/day per rat s.c. for 1 week--group III) and ADR plus LMWH group (7.5 mg/kg ADR on day 1 of study period followed by LMWH treatment, 300 microg/day per rat commencing on day 8 and continued for a week. At the end of the 2-week experimental period, all animals were terminated. Cellular damage was assessed in terms of serum and tissue lactate dehydrogenase (LDH), aminotransferases and alkaline phosphatase (ALP) activities. Creatine phosphokinase (CPK) was assessed in the serum and heart tissue. The role of LMWH in altering the oxidative stress in ADR-induced toxicity was evaluated on the basis of its influence on cardiac and hepatic lipid peroxidation and antioxidant status (enzymatic and non-enzymatic)--superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), reduced glutathione (GSH), alpha-tocopherol (Vitamin E) and ascorbate (Vitamin C). LMWH administration to ADR-induced rats prevented the rise in serum and tissue levels of LDH, aminotransferases and ALP, while these parameters were significantly elevated in the ADR group in comparison with the control group. Cardiotoxicity indicated by rise in serum CPK in the ADR group was attenuated by LMWH treatment in group IV. LMWH decreased the cardiac and hepatic lipid peroxidation induced by ADR. Histologic examination revealed that the ADR-induced deleterious changes in the heart and liver tissues were offset by LMWH treatment. Restoration of cellular normalcy accredits LMWH with cytoprotective role in adriamycin-induced cardiac and hepatic toxicity.     

Protective effect of Piper longum L. on oxidative stress induced injury and cellular abnormality in adriamycin induced cardiotoxicity in rats

Effect of methanolic extract of fruits of P. longum (PLM) on the biochemical changes, tissue peroxidative damage and abnormal antioxidant levels in adriamycin (ADR) induced cardiotoxicity in Wistar rats was investigated. PLM was administered to Wistar albino rats in two different doses, by gastric gavage (250 mg/kg and 500 mg/kg) for 21 days followed by ip ADR (15 mg/kg) on 21st day. ADR administration showed significant decrease in the activities of marker enzymes aspartate transaminase, alanine transaminase, lactate dehydrogenase and creatine kinase in heart with a concomitant increase in their activities in serum. A significant increase in lipid peroxide levels in heart of ADR treated rats was also observed. Pretreatment with PLM ameliorated the effect of ADR on lipid peroxide formation and restored activities of marker enzymes. Activities of myocardial antioxidant enzymes like catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase along with reduced glutathione were significantly lowered due to cardiotoxicity in rats administered with ADR. PLM pretreatment augmented these endogenous antioxidants. Histopathological studies of heart revealed degenerative changes and cellular infiltrations in rats administered with ADR and pretreatment with PLM reduced the intensity of such lesions. The results indicate that PLM administration offers significant protection against ADR induced oxidative stress and reduces the cardiotoxicity by virtue of its antioxidant activity.     

Effect of heparin and antivenom on skeletal muscle damage produced by Bothrops jararacussu venom

We examined the effect of treatment with heparin and polyvalent antivenom on mice muscle Extensor digitorum longus (EDL) regeneration, after damage induced by injection of Bothrops jararacussu crude venom over the muscle of the right posterior limb. The mice were separated into groups and each group received treatment, by intravenous route with either high molecular weight heparin (H), low molecular weight heparin (LMWH), polyvalent antivenom (PAV) or with the combination of PAV plus H or PAV plus LMWH at 15 minutes and 4 hours after the injection of the venom. Myotoxicity was measured by the increase in plasma creatine kinase (CK) activity at two hours after the injection of the venom. The histological changes in EDL at 1, 3, 7 and 21 days after the injection of the venom were analyzed by light microscopy. In each group the normal and regenerated muscle fibers were quantified using Scion Image computer program. We also evaluated in vitro, the influence of these substances in the proteolytic and phospholipase activities of the venom. Heparins decreased the proteolytic activity of the venom but did not affect its phospholipase activity. However the PAV antagonized both activities. PAV and its combinations showed antimyotoxic activity, according to the magnitude of CK plasma levels. At 21 days the regeneration was observed in all animals, also in those that received only the venom. All treatments, except LMWH, promote a significant increase in the number of muscle fibers.     

低分子肝素对子痫前期大鼠炎症反应、肝功能及胎盘组织Bcl-2、Bax蛋白表达的影响

目的:研究低分子肝素对子痫前期大鼠炎症反应、肝功能及胎盘组织Bcl-2、Bax蛋白表达的影响.方法:将90只孕期大鼠以随机数表法分成正常孕组、子痫前期组、治疗组,每组30只.其中子痫前期组和治疗组大鼠于妊娠第13 d开始皮下注射左旋硝基精氨酸甲酯,建立子痫前期大鼠模型,注射剂量为200mg/(kg·d),正常孕组予以等...     

A Comparison of the Long-Term Effects of Lanthanum Carbonate and Calcium Carbonate on the Course of Chronic Renal Failure in Rats with Adriamycin-Induced Nephropathy

Lanthanum carbonate (LA) is an effective phosphate binder. Previous study showed the phosphate-binding potency of LA was twice that of calcium carbonate (CA). No study in which LA and CA were given at an equivalent phosphate-binding potency to rats or humans with chronic renal failure for a long period has been reported to date. The objective of this study was to compare the phosphate level in serum and urine and suppression of renal deterioration during long-term LA and CA treatment when they were given at an equivalent phosphate-binding potency in rats with adriamycin (ADR)-induced nephropathy. Rats were divided into three groups: an untreated group (ADR group), a CA-treated (ADR-CA) group and a LA-treated (ADR-LA) group. The daily oral dose of LA was 1.0 g/kg/day and CA was 2.0 g/kg/day for 24 weeks. The serum phosphate was lower in the ADR-CA or ADR-LA group than in the ADR group and significantly lower in the ADR-CA group than in the ADR group at each point, but there were no significant differences between the ADR and ADR-LA groups. The serum phosphate was also lower in the ADR-CA group than in the ADR-LA group, and there was significant difference at week 8. The urinary phosphate was significantly lower in the ADR-CA group than in the ADR or ADR-LA group at each point. The urinary phosphate was also lower in the ADR-LA group than in the ADR group at each point, and significant difference at week 8. There were no significant differences in the serum creatinine or blood urea nitrogen among the three groups. In conclusion, this study indicated the phosphate-binding potency of LA isn’t twice as strong as CA, and neither LA nor CA suppressed the progression of chronic renal failure in the serum creatinine and blood urea nitrogen, compared to the untreated group.     

Cardiac and renal antioxidant enzymes and effects of tempol in hyperthyroid rats

This study evaluated the activity of cardiac and renal antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR)] and whether chronic treatment with tempol, a cell membrane-permeable SOD mimetic, ameliorates the hypertension of hyperthyroidism. Two experiments were performed. In experiment I, the following four groups of male Wistar rats were used: control group and three groups that received thyroxine (T4) at 10, 50, or 75 microg x rat(-1) x day(-1). In experiment II, tempol was orally administered (18 mg x kg(-1) x day(-1)) to control and T4-treated (75 microg x rat(-1) x day(-1)) rats. All treatments were maintained for 6 wk. Body weight, tail systolic blood pressure (BP), and heart rate were measured one time a week, and direct BP and morphological, metabolic, plasma, and renal variables were measured at the end of the experiment. Enzymatic activities were measured in renal cortex and medulla and right and left ventricles. In renal cortex, SOD activity was decreased in the T4-75 group, and there was a dose-related increase in CAT activity and decrease in GPX and GR activities in T4-treated groups. Activity of all antioxidant enzymes was reduced in left ventricle in T4-50 and T4-75 groups and in right ventricle in the T4-75 group. Tempol reduced BP, plasma malondialdehyde, and total urinary excretion of F2 isoprostanes in hypertensive hyperthyroid rats but not in controls. Tempol did not improve cardiac hypertrophy, proteinuria, or creatinine clearance in hyperthyroid rats. In conclusion, the results obtained indicate that the activity of SOD, GPX, and GR in renal and cardiac tissues is decreased in hyperthyroidism and that antioxidant treatment with tempol ameliorates T4-induced hypertension.     

Remedial effect of DL-α-lipoic acid against adriamycin induced testicular lipid peroxidation

Adriamycin (ADR), a cytotoxic antineoplastic drug is used in the treatment of various solid tumors. However, its efficacy continues to be challenged by significant toxicities including testicular toxicity. In the present study, the effect of lipoic acid, a "universal antioxidant" was investigated on ADR induced peroxidative damages in rat testis. Adult male albino rats of Wistar strain were administered ADR (1 mg/kg body weight, i.v.) once a week for 10 weeks. ADR injected rats showed a significant decline in the activities of enzymic antioxidants (catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase) and non-enzymic antioxidants (reduced glutathione, Vitamin A, Vitamin C and Vitamin E) with high malondialdehyde levels. The extent of testicular toxicity was evident from the decreased activities of testicular marker enzymes (sorbitol dehydrogenase and glucose-6-phosphate dehydrogenase). Treatment with lipoic acid (35 mg/kg body weight, i.p.) one day prior to ADR administration, maintained near normal activities of the enzymes and significantly reduced lipid peroxidation, thereby proving it to be an effective cytoprotectant.     

低分子肝素的抗炎作用及机制

低分子肝素(low molecular weight heparin, LMWH)除作为抗凝血和抗血栓药在临床上广为应用外,近年来其抗炎活性也颇受重视.LMWH抗炎机制涉及炎症细胞、炎症因子和黏附分子等环节.目前对LMWH的抗炎机制研究还处在初级阶段,但是LMWH独特的性质使其有望成为有效且安全的新型抗炎药物.     

低分子量肝素对妊高征大鼠肾脏病变的保护作用及机制初步探讨

目的:研究低分子量肝素(LMWH)对妊高征大鼠肾脏损伤的作用及其细胞内信号转导机制.方法:采用注射L-NAME方法制备妊高征动物模型,将妊娠大鼠随机分为正常妊娠组、妊高征组、LMWH治疗组,测定各组平均动脉压、尿蛋白、血肌酐及血尿素氮,观察LMWH对肾脏各指标的影响及肾脏出现的病理学变化;同时采用免疫组化、RT-PCR及Western Blot方法检测ERK1/2在各组的表达变化.结果:LMWH治疗组肾脏组织ERK1/2的蛋白及mRNA表达水平明显低于妊高征组(P＜0.01),而妊高征组肾脏组织ERK的蛋白及mRNA表达水平明显高于正常妊娠组(P＜0.01),ERK1与ERK2在各组大鼠肾脏中的表达无差异;治疗组平均动脉压及尿蛋白明显低于非治疗组(P＜0.05),但仍未达正常妊娠水平;HE染色和PAS染色为治疗组肾小球系膜增生、基底膜增厚较非治疗组明显减轻.ERK蛋白主要分布于肾小球中.结论:LMWH对妊高征大鼠肾脏损伤具有一定的防护作用,其机制可能是通过下调ERK1/2的表达来实现.     

The biogeochemical cycle of methane in the coastal zone and littoral of the Kandalaksha Bay of the White Sea

Microbiological and biogeochemical investigations of the processes of methane production (MP) and methane oxidation (MO) in the coastal waters and littoral of the Kandalaksha Bay of the White Sea were carried out. The studies were conducted in the coastal zones and in the water areas of the Kandalaksha Preserve, Moscow University White Sea Biological Station, and Zoological Institute (RAS) Biological Station in August, 1999, 2000, and 2001 and in March, 2001. The rate of CO2 assimilation in the shallow and littoral sediments was 35-27800 microg C/(dm3 day) in summer and 32.8-88.9 microg C/(dm3 day) in winter. The maximal rates of MP were observed in the littoral sediments in the zone of macrophyte decomposition, in local depressions, and in the estuary of a freshwater creak (up to 113 microl/(dm3 day)). The maximal level of MO was observed in the shallow estuarine sediments (up to 2450 microl/(dm3 day)). During the winter season, at the temperature of -0.5 to 0.5 degrees C, the MP rate in the littoral sediments was 0.02-0.3 microl/(dm3 day), while MO rate was 0.06-0.7 microl/(dm3 day). The isotopic data obtained indicate that the C(org) of the mats and of the upper sediment layers is enriched with the heavy 13C isotope by 1-4 per thousand as compared to the C(org) of the suspension, comprised on 33.5-34.3% of phytoplankton. A striking difference was found between the levels of methane emission by the typical littoral microlanscapes. In fine sediments, the average emission was 675 microl CH4/(m2 day), in the stormy discharge stretch sediments it was 1670 microl CH4/(m2 day), and under the stones and in silted pits, 1370 microl CH4/(m2 day). The calculation performed with consideration of the microlandscape areas with a high production allowed the CH4 production of 1 km2 of the littoral to be estimated as 192-300 1 CH4/(km2 day).     

Hypersulfated low molecular weight heparin with reduced affinity for antithrombin acts as an anticoagulant by inhibiting intrinsic tenase and prothrombinase

In buffer systems, heparin and low molecular weight heparin (LMWH) directly inhibit the intrinsic factor X-activating complex (intrinsic tenase) but have no effect on the prothrombin-activating complex (prothrombinase). Although chemical modification of LMWH, to lower its affinity for antithrombin (LA-LMWH) has no effect on its ability to inhibit intrinsic tenase, N-desulfation of LMWH reduces its activity 12-fold. To further explore the role of sulfation, hypersulfated LA-LMWH was synthesized (sLA-LMWH). sLA-LMWH is not only a 32-fold more potent inhibitor of intrinsic tenase than LA-LMWH; it also acquires prothrombinase inhibitory activity. A direct correlation between the extent of sulfation of LA-LMWH and its inhibitory activity against intrinsic tenase and prothrombinase is observed. In plasma-based assays of tenase and prothrombinase, sLA-LMWH produces similar prolongation of clotting times in plasma depleted of antithrombin and/or heparin cofactor II as it does in control plasma. In contrast, heparin has no effect in antithrombin-depleted plasma. When the effect of sLA-LMWH on various components of tenase and prothrombinase was examined, its inhibitory activity was found to be cofactor-dependent (factors Va and VIIIa) and phospholipid-independent. These studies reveal that sLA-LMWH acts as a potent antithrombin-independent inhibitor of coagulation by attenuating intrinsic tenase and prothrombinase.     

Fluctuation of thrombin-antithrombin III complex in patients with acute myocardial infarction: influence of low-dose heparin administration.

The haemostatic parameters were studied within 14 days of acute myocardial infarction (AMI) in 103 patients randomly allocated into a group receiving low-dose heparin or into a group treated without anticoagulants. Patients with isotopic evidence of deep vein thrombosis were excluded from the analysis. An important formation of thrombin-antithrombin III complex (TAT) in the plasma was detected in the early stage of the disease. It was accompanied by an activation of plasma intrinsic fibrinolysis (IF), an elevation of fibrinogen and its degradation products (FDP) and a reduction of extrinsic plasma fibrinolytic activity (EF) together with normal levels of factor X, antithrombin III (AT III), protein C and alpha-2-antiplasmin. Sequentially studies periods of the disease revealed a diminution of TAT complex concentration in the plasma on the seventh day of AMI together with a rise of the both plasma fibrinolytic activities (IF, EF) as well as an elevation of fibrinogen and its degradation products, returning to the initial values on the 14 day of AMI. In the patients treated with heparin the augmentation of TAT complex in the plasma was prolonged until the fifth day of AMI. Moreover, heparin administration was connected with significantly higher levels of AT III and protein C along with a lower concentration of factor X and FDP on the seventh day of the disease. The fluctuation of fibrinolytic activities (IF, EF) in the plasma was heparin-independent. The present results indicate that low-dose heparin treatment modulates the plasmatic fluctuation of TAT complex as well as factor X, AT III and protein C levels in patients with acute myocardial infarction.     

The C-terminal fragment of axon guidance molecule Slit3 binds heparin and neutralizes heparin's anticoagulant activity

Slit3 is a large molecule with multiple domains and belongs to axon guidance families. To date, the biological functions of Slit3 are still largely unknown. Our recent study demonstrated that the N-terminal fragment of Slit3 is a novel angiogenic factor. In this study, we examined the biological function of the C-terminal fragment of human Slit3 (HSCF). The HSCF showed a high-affinity binding to heparin. The binding appeared to be heparin/heparan sulfate-specific and depends on the size, the degree of sulfation, the presence of N- and 6-O-sulfates and carboxyl moiety of the polysaccharide. Functional studies observed that HSCF inhibited antithrombin binding to heparin and neutralized the antifactor IIa and Xa activities of heparin and the antifactor IIa activity of low-molecular-weight heparin (LMWH). Thromboelastography analysis observed that HSCF reversed heparin's anticoagulation in global plasma coagulation. Taken together, these observations demonstrate that HSCF is a novel heparin-binding protein that potently neutralizes heparin's anticoagulation activity. This study reveals a potential for HSCF to be developed as a new antidote to treat overdosing of both heparin and LMWH in clinical applications.     

Proline Alters Antioxidant Enzyme Defenses and Lipoperoxidation in the Erythrocytes and Plasma of Rats: In Vitro and In Vivo Studies

In the present study, we investigated, in vivo (acute and chronic) and in vitro, the effects of proline on the activities of antioxidant enzymes such as catalase (CAT), glutathione peroxidase and superoxide dismutase (SOD) in erythrocytes and also investigated the effect on thiobarbituric acid-reactive substances (TBARS) in the plasma of rats. For the experiments, the number of animals per group ranged from eight to ten. For acute administration, 29-day-old rats received one subcutaneous injection of proline (18.2 μmol/g body weight) or an equivalent volume of 0.9% saline solution (control) and were killed 1 h later. For chronic treatment, buffered proline was injected subcutaneously into rats twice a day at 10 h intervals from the 6th to the 28th day of age. Rats were killed 12 h after the last injection. For in vitro studies, proline (30.0 μM to 1.0 mM) was added to the incubation medium. Results showed that acute administration of proline reduced CAT and increased SOD activities, while chronic treatment increased the activities of CAT and SOD in erythrocytes and TBARS in the plasma of rats. Furthermore, in vitro studies showed that proline increased TBARS in the plasma (0.5 and 1.0 mM) and CAT activity (1.0 mM) in the erythrocytes of rats. The influence of the antioxidants (α-tocopherol plus ascorbic acid) on the effects elicited by proline was also studied. Treatment with antioxidants for 1 week or from the 6th to the 28th day of age prevented the alterations caused by acute and chronic, respectively, proline administration on the oxidative parameters evaluated. Data indicate that proline alters antioxidant defenses and induces lipid peroxidation in the blood of rats.     

Dietary intake of arsenic, mercury and selenium by children from a German North Sea island using duplicate portion sampling

The dietary intake of arsenic, selenium and mercury was studied for children living on the North Sea island Amrum, Germany. Altogether, 98 duplicate portions were collected from 14 children (age 1.5-5.5 years) in April and May 1995 over a sampling period of 7 days, respectively. The element concentrations in duplicate samples were measured by atomic absorption spectrometry. The weekly As and Hg intake (median and range) was 2.31 and 0.89-6.75 microg/(kg(bw) x week) for As and 0.13 and 0.060-0.62 microg/(kg(bw) x week) for Hg. Compared with the provisional tolerable weekly intake (PTWI) for As and Hg as proposed by the WHO, German children from coastal areas reveal no health risks due to As and Hg dietary intake. The daily Se intake (median and range) was 19 and 6-160 microg/day. The appropriate Se intake of 10-40 microg/day, as recommended by the Austrian, German, and Swiss Nutrition Councils for 1-4 years-old children, was not reached in 8 out of 49 cases (16.3%), whereas the recommended Se intake, fixed at 15-45 microg/day for the 4-7 years-old children, was not reached in 15 out of 48 cases (31.3%).     

The effect of new anthracycline derivatives on the induction of apoptotic processes in human neoplastic cells

This study was an attempt to determine the effect of a selected anthracycline derivative, WP903, on apoptotic processes in human melanoma cells depending on intracellular concentrations of the compound, and to evaluate the significance of apoptosis induction for the cytotoxic effect of anthracycline antibiotics. It was found that the WP903, contrary to ADR (adriamycin) is a strong inducer of apoptotic processes in ME18 human melanoma cells regardless of their susceptibility to adriamycin and WP903. The cells were treated for 24 h with ADR (1 and 5 microg/ml) or WP903 (0.2 and 2 microg/ml). Apoptosis was detected with the use of annexin V-FITC and PI (propidium iodide) and with TUNEL assay. WP903 used at 0.2 microg/ml induced early apoptosis in 23% of ME18 cells and in 60% of ME18/R cells; at 2 microg/ml in 70% of each of cell line tested. Significant late apoptotic effect was observed in ME18 cells. In contrast, ADR was found to be a weak inducer of apoptotic events. The results suggest that apoptosis is not a mechanism directly related to the cytotoxic effect of anthracycline antibiotics.     

Modulatory role of lipoic acid on adriamycin-induced testicular injury

The present study investigated the protective efficacy of dl-alpha-lipoic acid (LA) on adriamycin (ADR)-induced oxidative damage in rat testis. Adult male albino rats of Wistar strain were administered ADR (1 mg/kg body weight, i.v.), once a week for 10 weeks. ADR injected rats showed increased oxidative stress with a concomitant decrease in cellular thiols. The mRNA level for phospholipid hydroperoxide glutathione peroxidase (PHGPx) was also significantly decreased by ADR administration. Transmission electron microscopic (TEM) observations of testicular germ cells revealed abnormal ultrastructural changes in ADR treated rats. Treatment with lipoic acid (35 mg/kg body weight, i.p.) 1 day prior to ADR administration, effectively reverted these abnormal changes towards normalcy. These findings indicate a cytoprotective role of LA in this experimental model of testicular toxicity.     

Effects of dietary grape proanthocyanidins on the growth performance,jejunum morphology and plasma biochemical indices of broiler chicks

Grape proanthocyanidins (GPCs) are a family of naturally derived polyphenols that have aroused interest in the poultry industry due to their versatile role in animal health. This study was conducted to investigate the potential benefits and appropriate dosages of GPCs on growth performance, jejunum morphology, plasma antioxidant capacity and the biochemical indices of broiler chicks. A total of 280 newly hatched male Cobb 500 broiler chicks were randomly allocated into four treatments of seven replicates each, and were fed a wheat–soybean meal-type diet with or without (control group), 7.5, 15 or 30 mg/kg of GPCs. Results show that dietary GPCs decrease the feed conversion ratio and average daily gain from day 21 to day 42, increase breast muscle yield by day 42 and improve jejunum morphology between day 21 and day 42. Chicks fed 7.5 and 15 mg/kg of GPCs show increased breast muscle yield and exhibit improved jejunum morphologies than birds in the control group. Dietary GPCs fed at a level of 15 mg/kg markedly increased total superoxide dismutase (T-SOD) activity between day 21 and day 42, whereas a supplement of GPCs at 7.5 mg/kg significantly increased T-SOD activity and decreased lipid peroxidation malondialdehyde content by day 42. A supplement of 30 mg/kg of GPCs has no effect on antioxidant status but adversely affects the blood biochemical indices, as evidenced by increased creatinine content, increased alkaline phosphatase by day 21 and increased alanine aminotransferase by day 42 in plasma. GPC levels caused quadratic effect on growth, jejunum morphology and plasma antioxidant capacity. The predicted optimal GPC levels for best plasma antioxidant capacity at 42 days was 13 to 15 mg/kg, for best feed efficiency during grower phase was 16 mg/kg, for best jejunum morphology at 42 days was 17 mg/kg. In conclusion, GPCs (fed at a level of 13 to 17 mg/kg) have the potential to be a promising feed additive for broiler chicks.