Des-Arg(9)bradykinin as a causal metabolite for autism spectrum disorder

BACKGROUND Early diagnosis and therapeutic interventions can greatly enhance the developmental trajectory of children with autism spectrum disorder(ASD).However,the etiology of ASD is not completely understood.The presence of confounding factors from environment and genetics has increased the difficulty of the identification of diagnostic biomarkers for ASD.AIM To estimate and interpret the causal relationship between ASD and metabolite profile,taking into consideration both genetic and environmental influences.METHODS A two-sample Mendelian randomization(MR)analysis was conducted using summarized data from large-scale genome-wide association studies(GWAS)including a metabolite GWAS dataset covering 453 metabolites from 7824 European and an ASD GWAS dataset comprising 18381 ASD cases and 27969 healthy controls.Metabolites in plasma were set as exposures with ASD as the main outcome.The causal relationships were estimated using the inverse variant weight(IVW)algorithm.We also performed leave-one-out sensitivity tests to validate the robustness of the results.Based on the drafted metabolites,enrichment analysis was conducted to interpret the association via constructing a protein-protein interaction network with multi-scale evidence from databases including Infinome,SwissTargetPrediction,STRING,and Metascape.RESULTS Des-Arg(9)-bradykinin was identified as a causal metabolite that increases the risk of ASD(β=0.262,SE=0.064,P_(IVW)=4.64×10^(-5)).The association was robust,with no significant heterogeneity among instrument variables(P_(MR Egger)=0.663,P_(IVW)=0.906)and no evidence of pleiotropy(P=0.949).Neuroinflammation and the response to stimulus were suggested as potential biological processes mediating the association between Des-Arg(9)bradykinin and ASD.CONCLUSION Through the application of MR,this study provides practical insights into the potential causal association between plasma metabolites and ASD.These findings offer perspectives for the discovery of diagnostic or predictive biomarkers to support clinical practice in treating ASD.

Bradykinin B_(2）受体在大鼠脑胶质瘤模型上的定位

目的 研究 Bradykinin选择性地开通恶性脑肿瘤血脑屏障的机理。方法 通过双重免疫组化染色法 ,确定 Bradykinin B2 受体存在的部位。结果 在正常脑组织和肿瘤组织中的毛细血管内皮细胞上不存在 B2 受体 ,肿瘤细胞表达高水平的 B2 受体。结论 我们推测小剂量 Bradykinin灌注能选择地打开肿瘤的血脑屏障而不影响正常血脑屏障通透性的机理在于肿瘤细胞表达高水平的 B2 受体。

Expression of HER2 and bradykinin B_1 receptors in precursor lesions of gallbladder carcinoma

AIM： To determine the expression of HER2 and bradykinin B1 receptors （B1R） in the two pathogenic models of gallbladder cancer： the metaplasia dysplasia carcino ma and the adenoma carcinoma pathways.METHODS： Receptor proteins were visualized by immunohistochemistry on 5-μm sections of paraffin-embedded tissue. Expression of both receptors was studied in biopsy samples from 92 patients （6 males and 86 females; age ranging from 28 to 86 years, mean 56 years）. High HER2 expression in specimens was additionally investigated by fluorescence in situ hybridization. Cell proliferation in each sample was assessed by using the Ki-67 proliferation marker.RESULTS： HER2 receptor protein was absent in adenomas and in normal gallbladder epithelium. On the contrary, there was intense staining for HER2 on the basolateral membrane of epithelial cells of intestinal metaplasia （22/24; 91.7%） and carcinoma in situ （9/10; 90%）, the lesions that displayed a significantly high proliferation index. Protein up-regulation of HER2 in the epithelium with metaplasia or carcinoma in s/tu was not accompanied by HER2 gene amplification. A similar result was observed in invasive carcinomas （0/12）. The B1R distribution pattern mirrored that of HER2 except that B1R was additionally observed in the adenomas. The B1R appeared either as cytoplasmic dots or labeling on the apical cell membrane of the cells composing the epithelia with intestinal metaplasia （24/24; 100%） and carcinoma in situ （10/10; 100%） and in the epithelial cells of adenomas. In contrast, both HER2 （4/12; 33%） and B1R （1/12; 8.3%） showed a low expression in inva- sive gallbladder carcinomas.CONCLUSION： The up-regulation of HER2 and B1R in precursor lesions of gallbladder carcinoma suggests cross-talk between these two receptors that may be of importance in the modulation of cell proliferation in gallbladder carcinogenesis,

Angiotensin-converting enzyme and bradykinin gene polymorphisms and cough:A meta-analysis

AIM:To evaluate the association between genetic polymorphisms and angiotensin converting enzyme in-hibitor (ACEI)-related cough,and the race-or ethnicity-related difference in the prevalence of cough attributed to ACEI therapy.METHODS:We conducted a search in PubMed,EM-BASE,Cinahl,and the Cochrane Database without language limitation.A database of 11 studies on ACEI-related cough,with detailed information regarding ACE I/D or bradykinin B 2 receptor polymorphisms,was created.Eligible studies were synthesized using meta-analysis methods,including cumulative meta-analysis.A subgroup analysis was also performed using ethnicity.RESULTS:Six studies were included on ACE I/D poly-morphism (398 Caucasians,723 East Asians),and three studies were included on bradykinin B 2 receptor poly-morphism (300 East Asians).The distribution of ACE genotypes showed significant differences in the entire population (P=0.004) and in East Asians (P=0.005)but not in Caucasians (P=0.23).Allelic frequencies of ACE showed significant differences in East Asians [odds ratio (OR)=1.49 (1.11-2.02)].The meta-analysis with a random effects model showed a significant associa-tion between ACE allele I/D and ACEI-related cough [random effects (RE) OR=1.49 (1.11-2.02),P=0.009] in East Asians,but not in Caucasians [RE OR=0.90 (0.60-1.35)].The allelic frequencies of the bradykinin B 2 receptor gene were significantly different [OR=2.25 (1.42-3.57)].The distributions of the T/C genotypes of the bradykinin B 2 receptor gene were significantly dif-ferent (χ 2=8.366,P=0.015).The meta-analyses re-vealed that there was a significant association between the bradykinin B 2 receptor allele and ACEI-related cough in East Asians [RE OR=2.29 (1.42-3.69),P=0.001].CONCLUSION:ACE I/D and Bradykinin B 2 receptor polymorphisms contributed to the risk of ACEI-related cough in East Asians,but a negative association be-tween ACE I/D polymorphism and ACEI-related cough was observed in Caucasians.

Bradykinin postconditioning protects rat hippocampal neurons after restoration of spontaneous circulation following cardiac arrest via activation of the AMPK/mTOR signaling pathway

Bradykinin(BK)is an active component of the kallikrein-kinin system that has been shown to have cardioprotective and neuroprotective effects.We previously showed that BK postconditioning strongly protects rat hippocampal neurons upon restoration of spontaneous circulation(ROSC)after cardiac arrest.However,the precise mechanism underlying this process remains poorly understood.In this study,we treated a rat model of ROSC after cardiac arrest(induced by asphyxiation)with 150μg/kg BK via intraperitoneal injection 48 hours after ROSC following cardiac arrest.We found that BK postconditioning effectively promoted the recovery of rat neurological function after ROSC following cardiac arrest,increased the amount of autophagosomes in the hippocampal tissue,inhibited neuronal cell apoptosis,up-regulated the expression of autophagy-related proteins LC3 and NBR1 and down-regulated p62,inhibited the expression of the brain injury marker S100βand apoptosis-related protein caspase-3,and affected the expression of adenosine monophosphate-activated protein kinase/mechanistic target of rapamycin pathway-related proteins.Adenosine monophosphate-activated protein kinase inhibitor compound C clearly inhibited BK-mediated activation of autophagy in rats after ROSC following cardiac arrest,which aggravated the injury caused by ROSC.The mechanistic target of rapamycin inhibitor rapamycin enhanced the protective effects of BK by stimulating autophagy.Our findings suggest that BK postconditioning protects against injury caused by ROSC through activating the adenosine monophosphate-activated protein kinase/mechanistic target of the rapamycin pathway.

Lactotripeptides Inhibiting ACE1 Elevate the Plasma Bradykinin Concentration Acutely in a Placebo-Controlled, Double-Blind, Cross-Over, 4-Week Trial in Healthy Volunteers

This placebo-controlled, double-blind, cross-over intervention with twelve normotensive healthy volunteers tested the effects of milk products containing either 5 or 50 mg of ACE1-inhibitory lactotripeptides (isolecine-proline-proline, Ile-Pro-Pro, and valine-proline-proline, Val-Pro-Pro) and placebo milk drink (with similar taste) on plasma bradykinin levels. The subjects consumed one of the three test products in a random order, double-blinded, and four-week trial. On the first day (day 1) and on the last day (day 29) i.e. after four weeks’ treatment with one of the products, the acute effect with the same single dose was assayed. Other markers of the renin-angiotensin-aldosterone system (RAAS) were measured from plasma four times on the same days when we also assessed daytime urinary excretion of biomarkers of endothelial function. Neither acute nor prolonged administration of the ACE-1 inhibiting peptide drinks significantly lowered blood pressure of the normotensive subjects. The most important finding was the dose-dependent, and linear increase in plasma bradykinin concentrations after acute dosing on the first day;it was nearly statistically significant also on the day 29 (p 0.06). Other indicators of RAAS or endothelial function did not differ from those of placebo after the acute or prolonged treatments. Our results suggest that even weak inhibitors of ACE-1, such as the lactotripeptides Ile-Pro-Pro and Val-Pro-Pro, are able to diminish the breakdown of bradykinin and therefore increase plasma bradykinin levels. This may partly explain the blood pressure lowering and vasodilatory effects of lactotripeptides, shown by us earlier in mildly hypertensive subjects.

Effects of Bradykinin B_2 Receptor Blockade on Infarct Size and Hemodynamics after Myocardial Infarction in Enalapril-treated Rats

Objectives To study the effects of bradykinin （BK） B2 receptor blockade on infarct size and hemodynamics after myocardial infarction （MI） in rats with angiotensin-converting enzyme （ACE） inhibition therapy. Methods MI was produced by ligating the left coronary artery. The effects of enalapril （ 500 μg/kg·day）, enalapril （ 500 μg/kg · day） with BK B2 receptor antagonist Hoe-140 （500 μg/kg · day）, angiotensin Ⅱ （Ang Ⅱ） type 1 （AT1） receptor antagonist losartan （3 mg/kg · day） on infarct size, left ventricular systolic pressure （ LVSP）, cardiac output index （CI） and stroke volume index （SVI） were observed in rats after MI. Treatments were started on the 2nd day after MI and continued for another 6 weeks. Results Enalapril reduced infarct size and improved CI and SVI compared with the untreated MI group （ P 〈 0. 05 ）, and these effects of enalapril were significantly blunted by concomitant treatment with Hoe-140 （P 〈 0. 05）. Losartan was less effective than enalapril. LVSP were unchanged in the three treatment groups. Conclusions BK can reduce infract size and improve hemodynamics in rats following MI. The cardioprotective effects of ACEI partly result from the action of BK exerted through the B2 receptor.

Down-regulation of Cardiac Bradykinin B2 Receptors and eNOs mRNA in Rats with Remnant Kidneys

The changes in the expression of cardiac bradykinin B2 receptors (BKB2Rs) and endogenous nitrix oxide synthase (eNOs) mRNA were studied in rats with remnant kidneys. Thirty-two rats were divided into sham-operated and experimental groups randomly (n=16 in each group). The remnant kidney model was established by 2-stage 5/6 nephrectomy. Blood pressure and serum Cr were measured before operation and 15, 30, 60, 120 days after 5/6 nephrectomy. Eight animals in each group were killed at the first month and 4th month after the operation. The expression of BKB2Rs and eNOs mRNAs was detected by using RT-real time PCR from isolated left ventricle, and their correlation was also analyzed. The results showed that blood pressure and serum Cr were increased significantly 15 days after 5/6 nephrectomy (both P<0.01), and the hypertension and azomia existed constantly till 120 days but had no significant fluctuation. Cardiac BKB2Rs and eNOs mRNA was declined time-dependently (both P<0.05). And there was a close positive correlation between cardiac BKB2Rs and eNOs mRNA (r=0.82, P<0.01). It was suggested that a significant chronic renal failure can be produced at least 15 days after 5/6 nephrotomy and can sustain more than 4 months. The expression of BKB2Rs and eNOs was down-regulated time-dependently in this model, and there was a significant correlation between them.

Effects of Bradykinin on the Expression of Interleukin-6 in C6 Glioma Cells

OBJECTIVE There is a close correlation between interleukin-6 （IL-6） and malignant proliferation of gliomas. We investigated the effect of bradykinin on the expression of IL-6 in C6 glioma cells. METHODS Semi-quantitive RT-PCR and radioimmunoassay were used to examine the effect of bradykinin on the expression of IL-6 in C6 glioma cells and on the level of IL-6 in the culture medium. RESULTS Using semi-quantitive RT-PCR, the expression of IL-6 mRNA was examined in C6 glioma cells at 0, 5, 10,15, 30, 60 rain following addition of 1μmol/L bradykinin. There was no statistical difference in expression of IL-6 mRNA between the treatment and control groups （P〉0.05） and IL-6 was not detected in the cell culture medium. CONCLUSION Within an hour, IL-6 expression in C6 glioma cells is not induced by bradykinin, suggesting that its clinical application may be useful as a potential therapeutic agent for tumors of the central nervous system .

Expression of bradykinin as a substrate of CD26 /DPP IV in rats ischemia/reperfusion injury following lung transplantation

Objective To investigate the expression of bradykinin as a substrate of CD26 /DPP IV in rats with ischemia/reperfusion injury following lung transplantation ( LTx) . Methods Thirty - six syngeneic male SD rats were randomly allocated into control group and experimental group ( n = 18 each) ,and 36 rats served as do-

槲皮素通过下调缓激肽受体B1表达减轻糖尿病大鼠神经病理性疼痛

目的:研究槲皮素通过下调缓激肽受体B1(BDKRB1)表达减轻糖尿病大鼠神经病理性疼痛的机制。方法:60只大鼠腹腔注射60 mg/kg链脲佐菌素建立糖尿病神经病理性疼痛(DNP)大鼠模型,采用随机数表法平均分为5组:模型组、槲皮素(100 mg/kg)组、BDKRB1过表达质粒组、空载质粒组、槲皮素(100 mg/kg)+BDKRB1过表达质粒组,另选12只大鼠腹腔注射等剂量生理盐水作为对照组。各组大鼠以药物分组干预处理后,检测大鼠机械性刺激痛觉、热刺激痛觉与冷刺激痛觉,比较各组机械性缩足阈值、冷刺激抬足时间、热敏潜伏期;免疫组织化学染色检测大鼠脊髓背根神经节淋巴细胞浸润情况,比较各组淋巴细胞功能相关抗原-1(LFA-1)阳性细胞比例;试剂盒测量大鼠血清炎症介质IL-17、环氧化酶-2(COX-2)、IL-18水平;RT-qPCR、Western blot分别检测大鼠脊髓背根神经节BDKRB1 mRNA及蛋白表达水平。结果:与对照组比较,模型组大鼠机械性缩足阈值、热敏潜伏期显著降低(P<0.05),冷刺激抬足时间、LFA-1阳性细胞比例、血清IL-17、COX-2及IL-18水平、BDKRB1mRNA及蛋白表达水平显著升高(P<0.05);与模型组、槲皮素+BDKRB1过表达质粒组分别比较,槲皮素组大鼠机械性缩足阈值、热敏潜伏期均升高(P<0.05),冷刺激抬足时间、LFA-1阳性细胞比例、血清IL-17、COX-2及IL-18水平、BDKRB1 mRNA及蛋白表达水平均降低(P<0.05);BDKRB1过表达质粒组大鼠机械性缩足阈值、热敏潜伏期均降低(P<0.05),冷刺激抬足时间、LFA-1阳性细胞比例、血清IL-17、COX-2及IL-18水平、BDKRB1 mRNA及蛋白表达水平均升高(P<0.05);空载质粒组大鼠各指标均无显著变化(P>0.05)。结论:槲皮素通过下调BDKRB1表达抑制炎症,减少淋巴细胞浸润,减轻糖尿病大鼠神经病理性疼痛症状。

Initial bradykinin triggers calcium-induced calcium release in C6 glioma cells and its significance

Objective To investigate the underlying mechanism for the selective modulation of the permeability of blood-tumor barrier(BTB) by small dose of bradykinin(BK). Methods C6 glioma cells were treated with BK,and changes of intracellular nitric oxide(NO) and intracellular calcium level were measured with fluorescent spectrophotometer. Results The initial application of BK easily triggered extracellular calcium influx,which resulted in intracellular calcium store release in C6 glioma cells. The above mechanism w...

尖吻蝮蛇毒腺的缓激肽2型受体结合多肽的筛选与验证

蛇毒已被证明具有抗炎活性,其中包含许多免疫原性弱、活性强的短肽小分子。蛇毒腺是分泌毒液的器官,含有毒素成分及调控其分泌过程的大量生物活性成分。缓激肽2型受体(B2R)参与重要的细胞内信号通路,作为炎症的调节因子成为潜在的抗炎药物开发的靶点。为了获得特异性的B2R结合肽,利用尖吻蝮蛇Deinagkistro-don acutus毒腺T7噬菌体文库对靶点B2R进行3轮生物淘选,测序获得了多个具有潜在结合能力的序列。通过序列长度、溶解性预测、稳定性预测和分子对接等一系列生物信息学分析,最终确定1个含25个氨基酸的肽段,命名为DAvp-4。合成该肽段,通过表面等离子体共振技术验证了DAvp-4和B2R的结合能力,在脂多糖诱导的巨噬细胞模型及糖尿病视网膜病变小鼠模型中肯定了其抗炎作用。此研究不但获得了一个具有成药潜力的毒腺多肽,还显示了噬菌体展示技术在筛选天然产物成分研究中的有效性。

Effect of Bushenwenyanghuayu decoction on nerve growth factor and bradykinin/bradykinin B_1 receptor in a endometriosis dysmenorrhea mouse model

OBJECTIVE:To observe the effects of Bushenwenyanghuayu decoction(BD),a Traditional Chinese Medicine(TCM),on the serum concentration of nerve growth factor(NGF) and bradykinin(BK),and protein and mRNA levels of NGF and bradykinin B_1receptor(BKB1R) in a mouse model of endometriosis dysmenorrhea.METHODS:Seventy-five experimental female BALB/c mice were randomly divided into five groups,15 mice each:sham,model,BD high dose(61.67 g/kg),BD low dose(15.42 g/kg),and gestrinone(0.4 mg/kg) groups.All the mice except for those in the sham group underwent auto-transplantation surgery and were gavaged estradiol valerate(0.5 mg/kg,daily for 12 days) after surgery.On the 12 th day,1 h after administration,writhing response was induced by intraperitoneal injection of oxytocin at 2 U/mouse.The writhing frequency and latency were recorded and the volume of the ectopic foci was measured.The concentration of serum NGF and BK was detected by enzyme-linked immunosorbent assay,the protein expression of NGF and BKB1 R was tested by immunohistochemistry and western blotting,and NGF and BKB1 R mRNAs were detected by real-time PCR.RESULTS:Compared with the model group,the volume of the ectopic foci in the treatment groups was significantly lower(P < 0.01),the writhing frequency was decreased(P < 0.05),and the writhing latency was prolonged(P < 0.01).Compared with the sham group,serum NGF and BK levels in the model group were significantly increased(P <0.01).There were positive correlations for writhing frequency among the NGF and BK groups(P <0.01).The serum NGF and BK levels were significantly lower in the treatment groups than the model group(P < 0.05).The protein expression of NGF,BKB1 R was significantly decreased in the treatment groups compared with the model group(P < 0.01).NGF and BKB1 R mRNA expression was significantly decreased in the treatment groups compared with the model group(P < 0.01).CONCLUSION:NGF and BK/BKB1 R may play an important role in the development of endometriosis-associated dysmenorrhea,and BD was found to inhibit the development of endometriosis and relieve dysmenorrhea by influencing NGF and BK/BKB1 R mRNA and protein levels.

Compensatory function of bradykinin B1 receptor in the inhibitory effect of captopril on cardiomyocyte hypertrophy and cardiac fibroblast proliferation in neonatal rats

Background Bradykinin （BK） acts mainly on two receptor subtypes： B1 and B2, and activation of B2 receptor mediates the most well-known cardioprotective effects of angiotensin converting enzyme inhibitors （ACEi）, however, the role that B1 receptor plays in ACEi has not been fully defined. We examined the role of B1 receptor in the inhibitory effect of ACE inhibitor captopril on rat cardiomyocyte hypertrophy and cardiac fibroblast proliferation induced by angiotensin Ⅱ （Ang Ⅱ） and explored its possible mechanism. Methods Neonatal cardiomyocytes and cardiac fibroblasts （CFs） were randomly treated with Ang Ⅱ, captopdl, B2 receptor antagonist （HOE-140） and B1 receptor antagonist （des-Arg^10, Leu^9-kallidin） alone or in combination. Flow cytometry was used to evaluate cell cycle, size and protein content. Nitric oxide （NO） and intracellular cyclic guanosine monophosphate （cGMP） level were measured by colorimetry and radioimmunoassay. Results After the CFs and cardiomyocytes were incubated with 0.1 μmol/L Ang Ⅱ for 48 hours, the percentage of CFs in the S stage, cardiomyocytes size and protein content significantly increased （both P 〈0.01 vs control）, and these increases were inhibited by 10 μmol/L captopril. However, NO and cGMP levels were significantly higher than that with Ang Ⅱ alone （both P 〈0.01）. 1 μmol/L HOE-140 or 0.1 pmol/L des-Arg^10, Leu^9-kallidin attenuated the effects of captopril, which was blunted further by blockade of both B1 and B2 receptors. Conclusions Acting via B2 receptor, BK contributes to the antihypertrophic and antiproliferative effects of captopril on cardiomyocytes and CFs. In the absence of B2 receptor, B1 receptor may act a compensatory mechanism for the B2 receptor and contribute to the inhibition of cardiomyocyte hypertrophy and CFs proliferation by captopril. NO and cGMP play an important role in the effect of B1 receptor.

Crdioprotective effect of bradykinin-induced preconditioning mediated by calcitonin gene-related peptide in isolated rat heart

目的：研究降钙素基因相关肽（ＣＧＲＰ）在缓激肽预处理保护离体大鼠心脏中的调节作用．方法：Ｌａｎｇｅｎｄｏｒｆ法灌流心脏，观测心功能与肌酸激酶（ＣＫ）释放．结果：缓激肽显著改善再灌时心功能并减少ＣＫ释放．缓激肽的作用可被激肽受体拮抗剂Ｈｏｅ１４０（１μｍｏｌ·Ｌ－１）或ＣＧＲＰ受体拮抗剂ＣＧＲＰ８３７（０１μｍｏｌ·Ｌ－１）所取消预先用辣椒素处理也能取消缓激肽的作用．结论：缓激肽诱导预处理的心脏保护作用与促进ＣＧＲＰ的释放有关．

Circulating levels of hydroxylated bradykinin function as an indicator of tissue HIF-1a expression

The critical roles of oxygen homeostasis in metabolism are indisputable and hypoxic responses are correlated with the pathogenesis of gastrointestinal, pulmonary, renal diseases and cancers. Evaluating tissue hypoxia to predict treatment outcome is challenging, however, due to the lack of rapid, accurate and non-invasive methods. Hypoxia enhances prolyl-4-hydroxylase a1(P4HA1) expression, which can convert bradykinin(BK) to hydroxyprolyl-BK(Hyp-BK), leading us to hypothesize that circulating Hyp-BK/BK ratios may reflect tissue hypoxia and predict treatment outcomes. Direct quantification of Hyp-BK peptides in serum or plasma by conventional MALDI-TOF MS analysis is technically challenging. In our study, a nanopore-based fractionation and enrichment protocol was utilized to allow the simple workflow for circulating Hyp-BK/BK analysis. Hypoxia is linked to poor prognosis due to its role in promoting pancreatic cancer progression and metastasis. Here we show that P4HA1 expression was increased in pancreatic tumors versus adjacent tissue, associated with poor survival, and corresponded with tumor expression of the hypoxia inducible factor 1a(HIF-1a) and carbonic anhydrase 9(CA9). Hypoxiainduced P4HA1 expression and BK conversion to Hyp-BK were found to be HIF-1 a dependent, pretreatment serum Hyp-BK/BK ratios corresponded with tissue HIF-1 a and P4HA1 expression, and high Hyp-BK/BK levels corresponded with poor response to therapy. These results suggest that pretreatment circulating Hyp-BK/BK ratios may have value as a non-invasive, surrogate indicator of tissue hypoxia and tumor responses to therapy.

Effect of bradykinin on bradykinin-B2 receptor in rat aorticvascular smooth muscle cells and the involved signaltransduction pathways

The aim of this paper is to study the effect of bradykinin(BK)on bradykinin-B2 receptor as well as the possible involved signal transduction pathways in cultured rat aortic vascular smooth muscle cells(VSMCs).Rat aortic VSMCs were cultured.Cells after 4–6 passages were used in the experiment.VSMCs were incubated with BK,BK+B2 receptor inhibitor(HOE-140),BK+MEK inhibitor(PD98059),BK+mitogen-activated protein kinase(MAPK)inhibitor(apigenin),BK+phosphoinosi-tide 3-kinase(PI3K)inhibitor(LY294002),and BK+Akt inhibitor to evaluate the expression of B2 receptor and phosphorylation of signaling molecules MAPK,Akt,and PI3K by Western blot.(1)BK markedly up-regulated the expression of B2 receptor in VSMC.(2)Apigenin,PD98059,Akt inhibitor,and LY294002 inhibited up-regulation of B2 receptor induced by BK.(3)Signal transduction pathways of MAPK and PI3K were involved in the up-regulation of B2 receptor by BK mediation.Results suggest that bradykinin can up-regulate the expression of B2 receptor in VSMCs.

Ionic Mechanisms for the Acute Nociceptive Signals Induced by Bradykinin

Bradykinin is an inflammatory mediator and one of the most potent endogenous pain-inducing substances. When released at the site of tissue damage or inflammation

Role of Bradykinin on Left Ventricular Remodeling and Cardiac Function after Myocardial Infarction in Rats

Objectives To investigate the influences of bradykinin （BK） on hemodynamics, left ventricular hypertrophy and interstitial collagen metabolism after myocardial infarction （MI） in rats and the contribution of BK in angiotensin-converting enzyme （ACE） inhibition therapy. Methods By means of hemodynamic measurements, morphometric study of myocyte hypertrophy and SDS-PAGE technique, the effects of enalapril （500 μg.kg^-1.day^-1 ）, enalapril （500 μg.kg^-1.day^-1） with BK B2 receptor antagonist Hoe-140 （500 μg . kg^-1.day^-1）, angiotensin Ⅱ （AgⅡ） type 1 （AT1） receptor antagonist losartan （3 mg.kg^-1.day^-1 ） on mean arterial pressure （MAP）, left ventricular end-diastolic pressure （LVEDP）, as well as maximum positive left ventricular pressure change （ ＋ dp/dtmax）, V（m） n, collagen content and the ratio of type Ⅰ to type Ⅲ collagen （ Ⅰ / Ⅲ ） of noninfarcted area were observed in rats after MI. Treatments were started on the 3rd day after MI and continued for another 28 days. Results Enalapril reduced LV- EDP, V （m） n and collagen content as well as collagen Ⅰ /Ⅲ compared with the untreated MI group （ P 〈 0. 05 ）, and all of these effects of enalapril were partly blunted by concomitant treatment with hoe-140 （ P 〈 0. 05 ）. Losartan was less effective than enalapril （P 〈 0. 05 ）. However, three treatment groups had no significant differences in ＋ dp/dtmax and had similar reductions in MAP compared with untreated MI group. Conclusions BK can improve cardiac function and prevent left ventricular hypertrophy with myocardial fibrosis independent of blood pressure. The mechanisms of ACEI are both blockade of Ang Ⅱ formation and inhibition of BK degradation.