Background: Astragaloside IV (ASI) in Radix Astragali is believed to be the active component in treating heart failure. The present study aims to examine the effects of ASI on cardiovascular parameters in long-term heart failure in rats.
Abstract. The aim of the present study was to investigate the efficacy of recombinant human prourokinase (rhPro-UK) on thromboembolic stroke in rabbits. A total of 210 rabbits were used in experiments. The 180 thromboembolic stroke rabbits were divided into three therapeutic time windows with six groups in each time window (n=10). The model group was administered saline, the reagent groups were administered rhPro-UK (2.5x, 5x and 10x10 4 U/kg), and the positive control groups were administered 5x10 4 urokinase (UK) U/kg and 4.5 mg/kg recombinant human tissue plasminogen activator via intravenous infusion at 3, 4.5 and 6 h after embolism. The remaining 30 rats (that had not undergone occlusion by autologous blood clots) served as a sham group and were administered saline. The radioactive intensity was detected using a medical gamma counter before and after the administration of the drug for 15, 30, 45, 60, 75, 90, 105 and 120 min. At 24 h after treatment, the brain samples were coronally sliced into 5 mm sections and hemorrhage was estimated used a semiquantitative method by counting the number of section faces with hemorrhaging. The plasma was collected for prothrombin time, activated partial thromboplastin time, fibrinogen and thrombin time tests using a solidification method with a blood coagulation factor analyzer. In addition, α 2 -antiplasmin (α 2 -AP) was evaluated using ELISA methods using a RT-6100 microplate reader. At the 3 h time point, the thrombolysis rate of rhPro-UK(2.5x, 5x and 10x10 4 U/kg)
Danhong Injection (DHI) is widely used in clinics for treating cardiovascular and cerebrovascular diseases in China. However, the mode of action of DHI for neuroprotection remains unclear. In the present study, we deemed to investigate the effects of DHI on a rat model of cerebral ischemia/reperfusion injury (IRI) with an emphasis on its regulated gene profile obtained from microarray assays. Firstly, we showed that a 14-day DHI treatment effectively ameliorated severity of neurological deficits, reduced size of ischemic damage, improved status of oxidation stress, as well as systemic inflammation for IRI rats, along with which was a pronounced reduced cell infiltration in the area of periaqueductal gray matter. Secondly, bioinformatic analyses for the 429 differentially expressed genes (DEGs) regulated by DHI treatment pointed out ECM–receptor interaction, neuroactive ligand–receptor interaction, and endocytosis as the top three biological processes, while Toll-like recptor 4 (TLR4) as the most relavant singaling molecule. Lastly, we provided evidences showing that DHI might directly protect primary astrocytes from oxygen and glucose deprivation/re-oxygenation (OGD/Re) injury, the effects of which was associated with LAMC2 and ADRB3, two DEGs related to the top three biological processes according to transcriptomic analysis. In conlusion, we reported that DHI might work through maintaining the integrity for brain–blood barrier and to regulate TLR4-related signaling pathway to diminish the inflammation, therefore, effectively improved the outcomes of IRI. Our findings suggested that the attenuated astrocytic dysfunction could be a novel mechanism contributing to the neuroprotective effects of DHI against cerebral ischemia/reperfusion-induced damage.
Introduction
Recombinant neorudin (EPR-hirudin, EH) was developed through the addition of an EPR (Glu-Pro-Arg) peptide to the amino terminus of hirudin, which can be recognized and cut by coagulation factors XIa (FXIa) and/or Xa (FXa). In this study, the low-bleeding antithrombotic effects of EH were evaluated utilizing experimental models of thrombosis in rabbits and rats to provide a test basis for clinical trials.
Methods
The bleeding risks of EH and hirudin were first compared in mice by the tail-clipping method, and then the antithrombotic activity of EH was investigated in a rabbit model of arteriovenous bypass thrombosis and a rat model of thrombotic cerebral infarction.
Results
In mice, intravenous administration of EH at 1.5 mg/kg and 3 mg/kg did not affect the bleeding time compared with normal saline, while the administration of hirudin at 1.5 mg/kg prolonged the bleeding time by over 3 times the administration of normal saline. Furthermore, intravenous administration of EH had a significant dose-dependent inhibitory effect on the formation and development of arteriovenous bypass thrombosis and thrombotic cerebral infarction. Compared with an equimolar dose of hirudin, the antithrombotic effect of EH was similar, while the bleeding side effects were significantly attenuated. Moreover, when the antithrombotic effects were similar, EH had a shorter bleeding time and was associated with less bleeding than low molecular weight heparin (LMWH). EH had a therapeutic effect on thrombotic cerebral infarction without increasing the occurrence of cerebral hemorrhage.
Conclusion
The findings from the preclinical animal models used in this study showed that EH could not only effectively inhibit thrombus formation but also reduce the risk of bleeding.
The anticoagulant application is an effective treatment modality for cardiovascular diseases such as coronary heart disease, unstable angina pectoris, and myocardial infarction. In this study, the antithrombotic effect of recombinant neorudin (EPR‐hirudin, EH) was evaluated using a canine model of coronary artery thrombosis. A canine model with platelet thrombosis in the left circumferent branch of the coronary artery was designed using Folt's method, and the anti‐thrombus activity of EH was investigated. Femoral administration of EH intravenously had a significant dose‐dependent inhibitory effect on canine coronary artery thrombosis and the effective rates were 66.7% (p < .05), 83.3% (p < .05), and 100% (p < .01) after injection of 0.3, 1.0, and 3.0 mg/kg EH, respectively. Furthermore, EH demonstrated lower bleeding, with shorter bleeding time and less bleeding loss than low molecular weight heparin (LMWH). Under the similar effect intensity of EH and LMWH (85 IU/kg), the bleeding time of the EH group at 30 min was shorter, and the blood loss at 30–120 min was less than that of LMWH (p < .05 and p < .05–.001, respectively). EH had a significant dose‐dependent inhibitory effect in the dose range of 0.3–3.0 mg/kg on the coronary artery thrombosis and lower bleeding side effects than LMWH with a similar antithrombosis effect.
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