组胺H 1受体激动剂通过Akt/NF-κB通路抑制脂多糖诱导的星形胶质细胞炎症反应

目的探讨组胺H 1受体(histamine H 1 receptor,H 1R)对脂多糖(lipopolysaccharide,LPS)诱导的星形胶质细胞炎症反应的影响及其调控机制。方法采用LPS建立体外星形胶质细胞炎症模型,随机将大鼠原代星形胶质细胞分为对照组、LPS组、LPS+H 1R激动剂组(2-pyridylethlamine,Pyri)和H 1R激动剂组。对照组仅加入培养液,LPS+H 1R激动剂组提前在培养液中加入100μmol·L-1的Pyri,1 h后再加入终浓度为100μg·L-1的LPS。CCK-8法检测细胞活性;免疫荧光法检测活化标记物GFAP和H 1R的表达;倒置相差显微镜下观察星形胶质细胞的形态变化;ELISA法检测细胞上清中炎症因子TNF-α和IL-6水平;Western blot检测p-Akt、Akt、p-NF-κB p65、NF-κB p65的蛋白表达。结果与对照组比较,LPS组星形胶质细胞分支和辐射状突起减少,GFAP表达增加,细胞表面H 1R表达下调,上清液中TNF-α和IL-6含量增加,Akt和NF-κB p65的磷酸化水平明显增加;与LPS组相比,LPS+H 1R激动剂组激活态星形胶质细胞减少,GFAP表达降低,培养基上清中TNF-α和IL-6的含量明显下降,Akt和NF-κB p65的磷酸化表达明显降低。结论H 1R激动剂能够抑制LPS诱导的星形胶质细胞活化和炎症因子的表达,且Akt/NF-κB通路可能是H 1R参与星形胶质细胞免疫调节的重要途径。

Exosome-transported IncRNA H19 regulates insulin-like growth factor-1 via the H19/let-7a/insulin-like growth factor-1 receptor axis in ischemic stroke

LncRNA(long non-coding RNA) H19 is a transcript of the H19 gene that is expressed during embryogenesis.We previously discove red a role for circular lncRNA H19 in the onset and prognosis of cerebral ischemic stroke.In this study,we used serum from patients with ischemic stroke,and mouse and cell culture models to elucidate the roles of plasma and neuronal exosomes in the regulatory effect of lncRNA H19 on insulin-like growth factor-1 and its mechanism in ischemic stroke,using western blotting,quantitative real-time polymerase chain reaction,and enzyme-linked immunosorbent assays.Plasma exosomal IncRNA H19 was negatively associated with blood levels of insulin-like growth factor-1 in samples from patients with cerebral ischemic stroke.In a mouse model,levels of exosomal IncRNA H19 were positively correlated with plasma and cerebral lncRNA H19.In a cell co-culture model,we confirmed that IncRNA H19 was transported from neuro ns to astrocytes by exosomes to induce downregulation of insulin-like growth factor-1 through the H19/let-7 a/insulin-like growth factor-1 receptor axis.This study provides the first evidence for the transpo rtation of IncRNA H19 by exosomes and the relationship between IncRNA H19 and insulinlike growth factor-1.

Effects of AT1 receptor antagonist,Iosartan,on rat hepatic fibrosis induced by CCl_4

AIM To investigate effect of losartan,an AT1receptor antagonist,on hepatic fibrosis induced byCCl;and to determine whether or not AT1receptors are expressed on hepatic stellate cells,METHODS AND RESULTS Fifty male Sprague-Dawley rats,weighing（180±20）g,wererandomized into five groups（control group,modelgroup,and three losartan treated groups）,inwhich all rats were given the subcutaneousinjection of 40% CCl4（every 3 days for 6 weeks）except for rats of control group.Rats of losartan-treated groups were treated with losartan（20 mg/kg,10 mg/kg,5 mg/kg,daily gavage）,After 6weeks liver tissue and serum samples of all ratswere examined.Serum hyaluronic acid（HA）,procollagen typeⅢ（PCⅢ）were detected byradioimmunoassays,van Giesion collagen stainingwas used to evaluate the extracellular matrix of ratswith liver fibrosis.The expression of AT1receptors,transforming growth factor-beta（TGF-β）,and alpha-smooth muscle actin（a-SMA）inliver tissue were determined byimmunohistochemical techniques.Compared withmodel group,serum ALT and AST of losartan-treated groups were significantly reduced（t=4.20,P【0.01 and t=4.57,P【0.01）.Serum HAand PCⅢalso had significant differences（t=3.53,P【0.01 and t=2.20,P【0.05）.Thedegree of fibrosis was improved by losartan and correlated with the expressions of AT1 receptors,TGF-β,and α-SMA in liver tissue.CONCLUSION AT1 receptor antagonist,losartan,could limit the progression of the hepatic fibrosisinduced by CCl4.The mechanism may be related tothe decrease in the expression of AT1 receptorsand TGF-β,ameliorating the injury of hepatocytes;activation of local renin-angiotensin system mightrelate to hepatic fibrosis;and during progressionof fibrosis,activated hepatic stellate cells mightexpress AT1 receptors.

Effect evaluation of interleukin-1 receptor antagonist nanoparticles for mesenchymal stem cell transplantation

AIM: To study the efficacy of marrow mesenchymal stem cells (MSCs) transplantation combined with interleukin-1 receptor antagonist (IL-1Ra) for acute liver failure (ALF). METHODS: Chinese experimental miniature swine were randomly divided into four groups (n = 7), and all animals were given D-galactosamine (D-gal) to induce ALF. Group A animals were then injected with 40 mL saline via the portal vein 24 h after D-gal induction;Group B animals were injected with 2 mg/kg IL-1Ra via the ear vein 18 h, 2 d and 4 d after D-gal induction; Group C received approximately 1 × 108 green fluorescence protein (GFP)-labeled MSCs (GFP-MSCs) suspended in 40 mL normal saline via the portal vein 24 h after D-gal induction; Group D animals were injected with 2 mg/kg IL-1Ra via the ear vein 18 h after D-gal induction, MSCs transplantation was then carried out at 24 h after D-gal induction, and finally 2 mg/kg IL-1Ra was injected via the ear vein 1 d and 3 d after surgery as before. Liver function, serum inflammatory parameters and pathological changes were measured and the fate of MSCs was determined.RESULTS: The optimal efficiency of transfection (97%) was achieved at an multiplicity of infection of 80, as observed by fluorescence microscopy and flow cytometry (FCM). Over 90% of GFP-MSCs were identified as CD44+ CD90+ CD45-MSCs by FCM, which indicated that most GFP-MSCs retained MSCs characteristics. Biochemical assays, the levels of serum inflammatory parameters and histological results in Group D all showed a significant improvement in liver injury compared with the other groups (P < 0.05). The number of GFP-MSCs in Group D was also greater than that in Group B, and the long-term cell proliferation rate was also better in Group D than in the other groups.CONCLUSION: MSCs transplantation is useful in ALF, IL-1Ra plays an important role in alleviating the inflammatory condition, and combination therapy with MSCs transplantation and IL-1Ra is a promising treatment for ALF.

Effect of endothelin-1 receptor antagonists on histological and ultrastructural changes in the pancreas and trypsinogen activation in the early course of caerulein-induced acute pancreatitis in rats

AIM: To assess the effect of non-selective ETA/B (LU 302872)and selective ETA (LU 302146) antagonist on pancreatic histology and ultrastructure of acinar cells in connection with trypsinogen activation in early caerulein-induced AP.METHODS: Male Wistar rats with caerulein-induced AP,lasting 4 h, were treated i.p. with 10 and 20 mg/kg b.w.of each antagonist. Edema, inflammatory infiltration,necrosis and vacuolization of acinar cells in the pancreas were scored at 0-3 scale. Free active trypsin (FAT), total potential trypsin (TPT) after activation with enterokinase,and index of trypsinogen activation (%FAT/TPT) were assayed in pancreatic homogenates.RESULTS: In untreated AP, the edema, inflammatory infiltration, necrosis and vacuolization increased as compared to control healthy rats (P＜0.01). None of the treatment exerted any meaningful effect on the edema and inflammatory infiltration. The selective antagonist increased slightly the necrosis score to 0.82±0.06 at higher dose (P＜0.05) vs 0.58±0.06 in untreated AP. The nonselective antagonist increased slightly the vacuolization score to 2.41±0.07 at higher dose (P＜0.01) vs 1.88±0.08in untreated AP. The decrease in the number of zymogen granules, disorganization of endoplasmic reticulum,autophagosomes and cytoplasmic vacuoles were more prominent in treated AP than in untreated AP groups.%FAT/TPT in untreated AP increased about four times (18.4±3.8 vs4.8±1.3 in control group without AP, P＜0.001).Treatment of AP with both antagonists did not affect significantly augmented trypsinogen activation.CONCLUSION: The treatment with endothelin-1 receptors (non-selective ETA/B and selective ETA) antagonists has essential effect neither on the edema and inflammatory infiltration nor on trypsinogen activation observed in the early course of caerulein-induced AP. Nevertheless a slight increase of the necrosis and vacuolization score and some of the ultrastructural data could suggest the possibility of their undesired effects in caerulein-induced AP at investigated doses.

Design and synthesis of 2-alkylbenzimidazole derivatives as novel non-peptide angiotensin Ⅱ AT1 receptor antagonists

A series of 2-alkylbenzimidazole derivatives 9a-n have been designed and synthesized as a novel class of non-peptide angiotensin H AT1 receptor antagonists. The synthesized compounds were evaluated for their antagonism of angiotensin H, induced contraction in the rabbit thoracic aortic ring and the results showed that compounds 9a, 9g and 9j exhibited potent antagonistic activity of AT1 receptor.

Hypoxia inducible factor 1α promotes interleukin-1 receptor antagonist expression during hepatic ischemia-reperfusion injury

BACKGROUND Ischemia-reperfusion injury(IRI) is a major risk associated with liver surgery and transplantation,and its pathological mechanism is complex.Interleukin-1 receptor antagonist(IL-1ra) can protect the liver from IRI.However,the regulatory mechanism of IL-1ra expression is still unclear.AIM To identify the mechanism that could protect the liver in the early stage of IRI.METHODS To screen the key genes in hepatic IRI,we performed RNA sequencing and gene enrichment analysis on liver tissue from mice with hepatic IRI.Subsequently,we verified the expression and effect of IL-1ra in hepatic IRI.We also used promoter mutagenesis and chromatin immunoprecipitation assay to search for the transcriptional regulatory sites of hypoxia-inducible factor(HIF)-1α.Finally,to explore the protective mechanism of ischemic preconditioning(IP),we examined the expression of HIF-1α and IL-1ra after IP.RESULTS We identified IL-1ra as a key regulator in hepatic IRI.The expression of IL-1ra was significantly upregulated after hepatic IRI both in vivo and in vitro.Furthermore,we found that HIF-1αregulated Il-1ra transcription in response to hypoxia.Increased HIF-1α accumulation promoted IL-1ra expression,whereas inhibition of HIF-1α exhibited the opposite effect.We also confirmed a predominant role for hypoxia response element in the regulation of Il1ra transcription by HIF-1αactivation.Of note,we demonstrated that IP protects against hepatic IRI by inducing IL-1ra expression,which is mediated through HIF-1α.CONCLUSION We demonstrated that ischemia or hypoxia leads to increased expression of IL-1ra through HIF-1α.Importantly,IP protects the liver from IRI via the HIF-1α–IL-1ra pathway.

ANALYSIS OF INTERLEUKIN-1 RECEPTOR ANTAGONIST GENE POLYMORPHISM IN CHINESE PATIENTS WITH ALZHEIMER'S DISEASE

Objective To identify an interaction between the interleukin-1 receptor antagonist gene polymorphism and risk of Al-zheimer’s disease. Methods The study included 117 healthy controls, 85 patients with Alzheimer’s disease in a Northeastern Chinese popu-lation of Han nationality. Genotypes were determined by a polymerase chain reaction amplification of the intron 2 fragment, harbouring a variable number of short tandem nucleotide sequences. Amplification products were separated on a 2% agarose gel. Results The allele 2 frequency was 27% in healthy controls, and 21% in patients with Alzheimer’s disease. Thus for all-ele 2 as well as for all other alleles, genotypes, or carriage rates, no significant differences compared with controls. Conclusions No association of interleukin-1 receptor antagonist gene polymorphism with Alzheimer’s disease was iden-tified in this population. It is also possible that the increased risk and disease modifying effects are caused by linkage disequ-ilibrium with other genomic variants in other nearby genes.

Evaluation of a novel angiotensin II receptor 1 antagonist intesartan as anti-hypertension drug

Aim The preclinical studies of a novel angiotensin II receptor 1 antagonist 2-（4-（ （1,7＇-dimethyl-2＇- propyl-1H ,3 ＇H-2,5＇-bibenzo [ d ] imidazol-3＇-yl ） methyl） -1H-indol-l-yl ） benzoic acid （ intesartan ）. Methods The affinity to AT1 receptor of intesartan was tested through radioactive receptor binding assay by -y-counter. The anti-hypertensive activity in spontaneously hypertensive rats （SHRs） at different doses in vivo was tested by tail noninvasive arterial blood pressure measurement system. Pharmacokinetic parameters were analyzed by high per- formance liquid chromatography （HPLC） method. Besides, acute toxicity tests in ICR and Ames reverse mutation assay in tester strain （TA97, TA98, TA100 and TA102） was also detected. Results The binding assays sugges- ted that intesartan displayed high affinity to angiotensin II AT1 receptor with an ICs0 value of （0.36 ± 0. 18） nmol · L^-1. In vivo anti-hypertensive experiments showed that intesartan had an efficient and long-acting effect in reduc- ing blood pressure which could last more than 24 h at the doses of 2 mg· kg^-1, 5 mg · kg^-1 , and 10 mg · kg^-1 in spontaneously hypertensive rats. The minimum effective dose of it was 2 mg · kg^-1 and the T/P value was 54. 18%. Acute toxicity tests suggested that intesartan was safe with the LDs0 value of 526.20 mg · kg^-1. Ames assay proved that it would not cause the mutations of salmonella typhimurium. And the pharmacokinetic experiments showed that it could be absorbed efficiently and metabolized smoothly both in blood and in tissues in wistar rats. Conclusions Intesartan could be considered as a novel anti-hypertension candidate with efficient, long-acting and low toxicity chracteristics.

The interleukin-1 receptor antagonist (IL-1-Ra) and soluble tumor necrosis factor receptor I (sTNF RI) in periodontal disease

The course and severity of periodontitis can be significantly affected by bacterial virulence as well as host immunity dysfunction. Periodontal tissue destruction has been proved to result from cascade of cytokines synthesized by reactive cells upon stimulation by pathogenic bacteria and lipopolysaccharides within their cell membranes. The clinical use of genetically programmed cells, producing substances blocking IL-1, based on recombinant IL-1 antagonist, as well as cytokines activating fibroblasts and osteoblasts to regenerate the destroyed periodontal tissue could prove alternative to the conventional treatment. Another cytokine of interest in respect to periodontitis ethiopathogenesis is soluble tumor necrosis factor receptor I (sTNF RI). Observation of soluble TNF receptors as physiologic inhibitors of TNF led to its administration in therapeutic process as well as in therapy selected cases of aggressive periodontitis.

Novel Method for Synthesis of Diarylpyrazole Derivatives as Cannabinoid CB_1 Receptor Antagonists

A novel and efficient method was developed for the synthesis of diarylpyrazole derivatives as cannabinoid CB1 receptor antagonist via four step reactions. The key step was the synthesis of a diarylpyrazole skeleton, which involved initial condensation of the sodium salt of compound 12 with diazonium compounds, and further cyclization by heating at reflux in acetic acid. Eight diarylpyrazole derivatives and nine new synthesized compounds were characterized by 1H NMR, IR, MS, and elemental analysis. The reaction conditions were mild and the overall yields of the target compounds ranged from 26% to 44%.

Controlling Chemotherapy-Induced Nausea and Vomiting with Neurokinin-1 Receptor Antagonists in Patients on AC-Based Chemotherapy—Are We There Yet?

Chemotherapy-induced nausea and vomiting (CINV) are distressing side effects of chemotherapy. Neurokinin-1 receptor antagonists (NK1-RAs) have been incorporated in the contemporary management of CINV. However, clinical studies on NK1-RAs have shown mixed results in reducing CINV risk. Most studies focused on the use of aprepitant (APR) and casopitant (CAS) in breast cancer patients receiving AC-type (doxorubicin and cyclophosphamide) chemotherapy. In this study, we compared the study design and clinical efficacies of these NK1-RAs in reducing CINV risk. Among the selected eight studies, 4 APR Randomized Controlled Trials (RCTs), 2 APR Observational Studies (OSs) and 2 CAS RCTs were identified. Patient-related characteristics such as the proportion of females (60.0% - 100.0%), age (46.5 - 59.5 years), histories of motion (5.6% - 47.0% in NK1-RA arms) and morning sicknesses (14.2% - 45.0% in NK1-RA arms) and types of antiemetic regimens;as well as chemotherapy-related characteristics such as the proportion of patients on AC chemotherapy (15.0% - 100.0%) varied greatly. In terms of efficacies, both APR and CAS improved overall CR and vomiting in majority of the studies. None of the studies, however, demonstrated that NK1-RA could provide adequate nausea control. To conclude, NK1-RAs are effective in improving vomiting and overall CR, but not useful in controlling nausea or attaining CC, the ideal CINV endpoint. A shift in paradigm is needed for future CINV research. As healthcare providers continue to strive for optimum CINV control in their patients, we hope this review can help them make better informed clinical decisions.

Inhibition of Osteoarthritis in Rats by Electroporation with Interleukin-1 Receptor Antagonist

Gene therapy constitutes a promising strategy for the treatment of osteoarthritis (OA). We assessed the use of electroporation (EP) of non-viral gene vectors, and compared its efficacy with that of adeno-associated virus (AAV) vectors. EP- and AAV-mediated delivery of human interleukin-1 receptor antagonist (hIL-1Ra) was localized performed in the joints of rats following induction of OA. mRNA levels for hIL-1Ra, IL-1β, TNF-α, MMP-13 and ADAMTS-4 in the cartilage and synovial tissues were analyzed. Structural analyses of the subchondral bone at the medial femoral condyle were performed by Micro-CT after treatment. Knee joint specimens were staining with hematoxylin and eosin and Saffron O. Induction of hIL-1Ra by both EP and AAV inhibited inflammatory-induced sub-chondral bone reconstruction, and effectively suppressed IL-1β activity, as evidenced by decreased expression of MMP-13 and ADAMTS-4. Histological analyses revealed significant protection of cartilage, proteoglycan by EP and AAV. hIL-1Ra expression was similar in both the EP and AAV groups. Notably, this gene is not easier degraded transduced by EP compared with AAV. Taken together, these results show that EP offers transfection efficiency comparable to that of AAV, with the potential for longer gene expression, making EP a promising candidate for efficient non-viral delivery of OA gene therapy.

辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎有效性及安全性Meta分析

目的:系统评价辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎的有效性及安全性。方法:计算机检索中国知网(CNKI)、中国生物医学文献数据库(CBM)、万方数据库(Wanfang)、维普中文期刊(VIP)、Cochrane Library、Embase、PubMed数据库中有关辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎的随机对照试验。使用RevMan5.3和Stata15.0软件进行Meta分析。结果:共纳入7篇文献,涉及患者683例。Meta分析显示,辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎总有效率[RR=1.18,95%CI(1.11,1.25),P<0.0001]高于对照组;敏感性分析提示辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎的总有效率结果稳定。辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎的复发率[RR=0.27,95%CI(0.12,0.61),P=0.001]低于对照组,2组不良反应发生率比较,差异无统计学意义[RR=0.61,95%CI(0.26,1.40),P=0.24]。结论:辛芩颗粒联合H_(1)受体拮抗剂治疗变应性鼻炎的临床疗效优于单纯的H_(1)受体拮抗剂治疗,安全性较好。

白细胞介素1受体颉颃剂抑制脂多糖促奶牛外周血单个核细胞氧化应激损伤作用的研究

试验以脂多糖(LPS)为刺激源,以细胞活力、抗氧化指标和炎症因子为判断指标,探讨白细胞介素1受体颉颃剂(IL-1Ra)通过抑制白细胞介素1β(IL-1β)的活性,对LPS诱导外周血单个核细胞(Peripheral blood mononuclear cells,PBMCs)氧化损伤的缓解作用。试验采用单因子完全随机设计,PBMCs被随机分为7个组(每组6个重复),分别给予不同的处理:第1组是阴性对照组(Neg组),完全培养基培养30 h;第2组损伤组(Dam组),是在完全培养基中培养6 h后,再经10μg/mL的LPS工作液培养24 h;第3至7组(R0.25、R0.5、R1、R5组和R10组)细胞分别经浓度为0.25、0.5、1、5、10 ng/mL的IL-1Ra培养6 h,接着经10μg/mL的LPS工作液培养24 h。结果表明:与Neg组相比,Dam组的细胞活力、抗氧化相关酶[包括总抗氧化能力(T-AOC)以及总超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)和硫氧还蛋白还原酶(TrxR)]的活性显著降低,丙二醛(MDA)浓度、炎症因子白细胞介素-6(IL-6)和IL-1β含量以及诱导型一氧化氮合酶(iNOS)活性、一氧化氮(NO)含量均显著升高(P≤0.05)。与Dam组相比,R1组显著逆转了氧化损伤引起的上述抗氧化活性的降低和炎症因子浓度的升高,其他IL-1Ra处理组对上述指标的逆转效果不同程度地低于R1组(P≤0.05)。上述结果说明,LPS通过诱发PBMCs产生大量IL-1β进而导致细胞氧化损伤,IL-1Ra剂量依赖性地缓解了LPS引起的氧化损伤,添加剂量以1 ng/mL为宜。

Proton pump inhibitors therapy vs H_2 receptor antagonists therapy for upper gastrointestinal bleeding after endoscopy: A meta-analysis

AIM: To compare the therapeutic effects of proton pump inhibitors vs H2 receptor antagonists for upper gastrointestinal bleeding in patients after successful endoscopy.METHODS: We searched the Cochrane library, MEDLINE, EMBASE and Pub Med for randomized controlled trials until July 2014 for this study. The risk of bias was evaluated by the Cochrane Collaboration's tool and all of the studies had acceptable quality. The main outcomes included mortality, re-bleeding, received surgery rate, blood transfusion units and hospital stay time. These outcomes were estimated using odds ratios(OR) and mean difference with 95% confidence interval(CI). Rev Man 5.3.3 software and Stata 12.0 software were used for data analyses. RESULTS: Ten randomized controlled trials involving 1283 patients were included in this review; 678 subjects were in the proton pump inhibitors(PPI) group and the remaining 605 subjects were in the H2 receptor antagonists(H2RA) group. The meta-analysis results revealed that after successful endoscopic therapy, compared with H2 RA, PPI therapy had statistically significantly decreased the recurrent bleeding rate(OR = 0.36; 95%CI: 0.25-0.51) and receiving surgery rate(OR = 0.29; 95%CI: 0.09-0.96). There were no statistically significant differences in mortality(OR = 0.46; 95%CI: 0.17-1.23). However, significant heterogeneity was present in both the numbers of patients requiring blood transfusion after treatment [weighted mean difference(WMD),-0.70 unit; 95%CI:-1.64- 0.25] and the time that patients remained hospitalized [WMD,-0.77 d; 95%CI:-1.87- 0.34]. The Begg's test(P = 0.283) and Egger's test(P = 0.339) demonstrated that there was no publication bias in our meta-analysis.CONCLUSION: In patients with upper gastrointestinal bleeding after successful endoscopic therapy, compared with H2 RA, PPI may be a more effective therapy.

Recent Development in Thrombin Receptor Antagonist as Novel Antithrombotic Agent

Significant progress was achieved in the search of a thrombin receptor antagonist as a novel antithrombotic treatment since the thrombin receptor (protease-activated receptor-1, PAR-1) was cloned 20 years ago. Previous works have shown that it is possible to develop potent thrombin receptor antagonists to compete effectively with the receptor’s internal “tethered” ligand to block platelet activation. Vorapaxar (SCH 530348) from Schering-Plough (now Merck) and atopaxar (E5555) from Eisai have been advanced to human clinical trials. Recently, the pivotal phase III clinical trial results for vorapaxar were published. In this article we review these results plus the phase II results from atopaxar. Several newly described thrombin receptor antagonists from the literature will also be discussed. The phase III results from vorapaxar demonstrated that a thrombin receptor antagonist can achieve efficacy in addition to current standard- of-care in treating atherothrombotic patients, especially those with previous myocardial infarction (MI). However, the increased moderate and severe bleeding, especially intracranial bleeding, point to the limitations of current thrombin receptor antagonists. Future thrombin receptor antagonists that can improve on the efficacy and bleeding profile of current ones should have a promising place in meeting the unmet medical need in treating atherothrombotic patients using current standard therapy.

Medical therapy for clinical benign prostatic hyperplasia:α1 Antagonists,5α reductase inhibitors and their combination

Medical therapy for clinical benign prostatic hyperplasia(BPH)has advanced significantly in the last 2 decades.Many new a1 antagonists and 5a reductase inhibitors(5ARi)are now commercially available.The practicing urologist must decide on the most appropriate medication for his patients,taking into consideration various factors like efficacy,dosing regime,adverse effects,cost,patient’s socioeconomic background,expectations,drug availability and his own clinical experience.The use of combination therapy added further to the complexity in clinical judgment when prescribing.We highlight some of the key points in prescribing a1 antagonists,5ARi and their combination,based on our viewpoints and experience as urologists in an Asian clinical setting.

H_1 and H_2 receptors in the locus ceruleus are involved in the intracere-broventricular histamine-induced carotid sinus baroreceptor reflex reset-ting in rats

Objective To investigate the role of H1 and H2 receptors in the locus ceruleus （LC） in carotid sinus baroreceptor reflex （CSR） resetting induced by intracerebroventricular （i.c.v.） injection of histamine （HA）. Methods The left and right carotid sinus regions were isolated from the systemic circulation in 18 male Sprague-Dawley rats anesthetized with pentobarbital sodium. The intracarotid sinus pressure （ISP） was altered in a stepwise manner in vivo. ISP-mean arterial pressure （MAP） relationship curve and its characteristic parameters were constructed by fitting to the logistic function with five parameters. The changes in CSR performance induced by i.c.v. HA and the effects of pretreatment with H1 or H2 receptors selective antagonist, chlorpheniramine （CHL） or cimetidine （CIM） into the LC, on the responses of CSR to HA were examined. Results I.c.v. HA （100 ng in 5 μl） significantly shifted the ISP-MAP relationship curve upwards （P 〈 0.05） and obviously decreased the value of the reflex parameters such as MAP range and maximum gain （P 〈 0.05）, but increased the threshold pressure, saturation pressure and ISP at maximum gain （P 〈 0.05）. The pretreatment with CHL （0.5 μg in 1 μl） or CIM （1.5 μg in 1 μl） into the LC could obviously attenuate the changes mentioned above in CSR performance induced by HA, but the alleviative effect of CIM was less remarkable than that of CHL （P 〈 0.05）. Respective microinjection of CHL or CIM alone into the LC with the corresponding dose and volume did not change CSR performance significantly （P 〉 0.05）. Conclusion Intracerebroventricular administration of HA results in a rapid resetting of CSR and a decrease in reflex sensitivity, and the responses of CSR to HA may be mediated, at least in part, by H1 and H2 receptors activities in the LC, especially by H1 receptors. Moreover, the effects of the central HA on CSR might be related to a histaminergic descending pathway from the hypothalamus to LC.