Astrocytic endothelin-1 overexpression impairs learning and memory ability in ischemic stroke via altered hippocampal neurogenesis and lipid metabolism

Vascular etiology is the second most prevalent cause of cognitive impairment globally.Endothelin-1,which is produced and secreted by endothelial cells and astrocytes,is implicated in the pathogenesis of stroke.However,the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood.Here,using mice in which astrocytic endothelin-1 was overexpressed,we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia(1 hour of ischemia;7 days,28 days,or 3 months of reperfusion).We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion.Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6,which were differentially expressed in the brain,were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke.Moreover,the levels of the enriched differentially expressed proteins were closely related to lipid metabolism,as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis.Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine,sphingomyelin,and phosphatidic acid.Overall,this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.

Endothelin-1诱导的大鼠局灶性脑缺血再灌注模型

目的 研究Endothelin 1(ET 1)诱导的大鼠局灶性脑缺血再灌注模型。方法 将ET 1注入大脑中动脉 (MCA)附近 ,ET 1强烈的缩血管作用可使脑血流 (CBF)降低造成缺血性脑损伤 ,采用氢清除法监测缺血过程中大鼠纹状体脑血流的变化 ,于缺血后 6h进行神经功能评分 ,并采用TTC染色法观察脑梗死面积的变化。结果 ET 1可使纹状体血流呈现浓度依赖性的降低 ,10min时CBF降至最低 ,分别为 :ET 130 0 pmol组 (2 7 1± 2 9) %、36 0pmol组 (12 7±2 1) %、4 0 0pmol组 (11 9± 1 8) %、5 0 0 pmol组 (9 5±1 6 ) % ;神经功能评分显示ET 1可造成大鼠不同程度的神经功能损伤 ;MCAO后 2 4h ,脑梗死面积百分率随ET 1浓度的增加而呈上升趋势 ,并显示出良好的浓度依赖关系 :30 0pmol组 (3 9± 0 3) %、36 0 pmol组 (7 4± 0 5 ) %、4 0 0 pmol组 (11 3± 1 3) %、5 0 0 pmol组 (16 2± 1 8) % ;r =0 992 6(P <0 0 5 )。结论 该模型操作简单 ,造成的脑梗死范围稳定、重现性好 。

VEGF、Endostatin、Endothelin-1在大肠腺瘤及大肠癌中的表达及意义

目的探讨大肠腺瘤及大肠癌中血管内皮生长因子(VEGF)、内皮抑素(Endostatin)、内皮素(Endothelin-1)的表达与病理组织学特征的关系以及三者之间的关系及意义,并分析三者在大肠腺瘤癌变过程中的相互作用。方法分别应用聚合酶链式反应PCR法和免疫组织化学SP法,联合检测VEGF、Endostatin、Endothelin-1在20例大肠腺瘤、40例大肠癌及20例正常大肠组织中的表达情况,并分析其与大肠腺癌临床病理特征之间的关系。结果①在正常大肠组织、大肠腺瘤及大肠癌中,VEGF、Endothelin-1的阳性表达率呈依次递增,VEGF、Endothelin-1在大肠腺癌与正常大肠黏膜之间差异有显著性(P<0.01);Endostatin在正常大肠组织、大肠腺瘤及大肠癌中的阳性表达率呈依次递减,在大肠腺癌与正常大肠粘膜之间差异有显著性(P<0.01);②40例大肠腺癌中,VEGF、Endothelin-1的阳性表达率与肿瘤分化程度、浸润深度、淋巴结转移及远处转移密切相关,Dukes C+D期组高于Dukes A+B期组(P<0.05﹚;Endostatin表达与肿瘤分化程度、浸润深度、淋巴结转移及远处转移呈负相关,Dukes C+D期组低于Dukes A+B期组(P<0.05﹚。结论随着大肠癌的发生发展,VEGF、Endothelin-1的阳性表达率依次增加,提示可作为大肠腺癌发生发展的分子标志,二者在大肠腺癌的发生发展过程中可能具有协同促进作用;两者在大肠腺癌中的表达高于大肠腺瘤组,表明两者在腺瘤向腺癌转变的部分分子机制中起着重要作用。随着大肠腺癌的发生发展,Endostatin的表达逐渐降低,腺癌组低于腺瘤组,提示Endostatin在大肠癌的发生发展、腺瘤癌变的过程中可能受到抑制。联合检测VEGF、Endothelin-1和Endostatin的表达对筛选高危大肠腺瘤、判断大肠癌的发生发展、转移及预后具有重要的参考价值。

难治性胃溃疡患者血浆Endothelin-1浓度检测的意义

目的:检测难治性胃溃疡患者血浆Endothe lin-1水平,探讨其在难治性溃疡发病中的作用。方法:64例胃溃疡病患者给予正规抗溃疡病治疗,其中34例12周后经胃镜证实溃疡未愈合(难治性溃疡组);30例痊愈(溃疡愈合组)。分别检测两组患者治疗前后的血浆ET-1水平,20例健康体检者作为对照组。结果:治疗前,难治性溃疡组的平均血浆浓度(62.71±12.38)μg/L,显著低于溃疡愈合组(96.39±15.25)μg/L及健康对照组(86.29±11.23)μg/L),差异均有显著性(P<0.05),溃疡愈合组与对照组间差异无显著性。两组患者治疗前后的ET-1水平均无显著性变化。结论:难治性溃疡患者的ET-1水平偏低,可能导致新生血管的形成不足使得溃疡久治不愈。

Endothelin-1与前列腺癌及其骨转移

前列腺癌细胞endothelin -1(ET -1)表达水平升高。肿瘤细胞通过自分泌和旁分泌ET -1能够影响细胞的增殖、凋亡、侵袭以及血管生成和骨的重塑 。

康柏西普联合PRP治疗缺血型CRVO引起新生血管性青光眼的效果及对房水Klotho和Endothelin-1的影响

目的探讨康柏西普联合全视网膜光凝(PRP)治疗缺血型视网膜中央静脉阻塞(CRVO)引起新生血管性青光眼(NVG)的效果及对房水Klotho和Endothelin-1的影响。方法选取2019年12月—2020年12月80例缺血型CRVO引起的NVG(80只眼),根据治疗方法不同分为对照组和研究组,每组40例(40只眼)。对照组采用PRP治疗,研究组采用康柏西普联合PRP治疗。对比两组综合疗效、不良事件及复发情况。比较两组治疗前后眼压和最佳矫正视力(BCVA),房水Klotho、Endothelin-1、血管内皮生长因子(VEGF)、血小板反应蛋白-1(TSP-1)、细胞色素C(CytC)、线粒体融合蛋白1(Mfn1)水平,以及视网膜中央动脉舒张末期血流速度(EDV)、收缩期峰值血流速度(PSA)。结果研究组总有效率高于对照组(P<0.05)。治疗前、治疗后4和8周,两组眼压及房水Endothelin-1、VEGF、TSP-1、CytC水平呈降低趋势,BCVA、房水Klotho和Mfn1水平、视网膜中央动脉EDV和PSA呈升高趋势;且研究组治疗后4、8周上述指标降低和升高程度均优于对照组(P<0.05)。研究组不良事件发生率低于对照组(P<0.05)。两组复发率比较差异无统计学意义(P>0.05)。结论采用康柏西普联合PRP治疗缺血型CRVO引起NVG,能显著提高治疗效果,进一步提高患者视力水平,抑制新生血管生成,改善房水Klotho、Endothelin-1水平。

Effect of Lycium barbarum Polysaccharides on the expression of endothelin-1 and its receptors in an ocular hypertension model of rat glaucoma

Lycium barbarum, a traditional Chinese anti-aging herb, has been shown to protect retinal ganglion cells （RGCs） in a rat chronic ocular hypertension （COH） model. Here, we investigated the expression of endothelin-1 （ET-1）, a strong vasoconstrictor, and its receptors, ETA and ETB, in the COH model and assessed the effects of Lycium barbarum on the ET-1 axis. Elevated intraocular pressure （IOP） was induced in the right eye of SD rats using argon laser photocoagulation. （1） The expression of ET-1, ETA and ETB in normal and COH retinas was studied. （2） Some COH rats were fed daily with Lycium barbarum Polysaccharides （LBP） using 1 mg/kg or phosphate-buffered saline （PBS） for 3 weeks （started 1 week before photocoagulation）. The effects of LBP on the expression of ET-1 and its receptors, ETA and ETB, in COH retina were evaluated. A semi-quantitative analysis of staining intensity was used to evaluate the expression levels of ET-1, ETA and ETB in retinal vasculature. We found that （1） Under COH condition, the immunoreactivity of ET-1 was increased in retina associated with an increase of ETB receptor immunoreactivity and a decrease of ETA receptor immunoreactivity. （2） After feeding COH rats with LBP, the expression of ET-1 was decreased with an increase of ETA expression and a decrease of ETB expression in the retina, especially in RGCs. （3） By comparing the staining intensity in the vasculature of COH retina in LBP-fed group with PBS-fed group, there was a decrease in the expression of ET-1 and ETA and an increase in ETB. In summary, ET-1 expression was up-regulated in the retina in COH model. LBP could decrease the expression of ET-1 and modulate the expression of its receptors, ETA and ETB, under the condition of COH. The neuroprotective effect of LBP on RGCs might be related to its ability to regulate the ET-1-mediated biological effects on RGCs and retinal vasculature.

Endothelin-1 stimulates contraction and migration of rat pancreatic stellate cells

AIM： To examine the ability of FT-1 to affect the cell functions of PSCs and the underlying molecular mechanisms. METHODS： PSCs were isolated from the pancreas of male Wistar rats after perfusion with collagenase, and cells between passages two and five were used. Expression of ET-1 and FT receptors was assessed by reverse transcription-PCR and immunostaining. Phosphorylation of myosin regulatory light chain （MLC）, extracellular-signal regulated kinase （FRK）, and Akt was examined by Western blotting. Contraction of PSCs was assessed on hydrated collagen lattices. Cell migration was examined using modified Boyden chambers. Ceil proliferation was assessed by measuring the incorporation of 5-bromo-2＇- deoxyuridine. RESULTS： Culture-activated PSCs expressed ETA and ETB receptors, and ET-1. ET-1 induced phosphorylation of NLC and FRK, but not Akt. ET-1 induced contraction and migration, but did not alter proliferation of PSCs. FT-1-induced contraction was inhibited by an ETA receptor antagonist BQ-123 and an ETB receptor antagonist BQ-788, whereas migration was inhibited by BQ-788 but not by BQ-123. A Rho kinase inhibitor Y-27632 abolished both contraction and migration. CONCLUSION： ET-1 induced contraction and migration of PSCs through El receptors and activation of Rho-Rho kinase. ETA and FTB receptors play different roles in the regulation of these cellular functions in response to ET-1.

Effects of L-Tetrahydropalmatine on Energy Metabolism,Endothelin-1 and NO during Acute Cerebral Ischemia-reperfusion of Rats

To investigate the effects of L-tetrahydropalmatine (L-THP) on ener-gy metabolism, endothelin-1 (ET-1 ) and NO during acute cerebral ischemia-reperfusion of rats, 24 Wistar rats were randomly divided into four groups, with 6rats in each group: sham-operation group, simple ischemia group, ischemia-reperfusion group and treatment group (L-THP group). Cerebral ATP, lactate,ET-1 and NO levels were measured in all groups. Our results showed that treat-ment with L-THP could increase cerebral ATP levels, but decrease cerebral lac-tate, ET-1 and NO concentrations during ischemia-reperfusion in the treatmentgroup. It is concluded that L-THP could improve cerebral energy metabolism and protect the injured brain tissue, the mechanism of which might be related to suppression of overproduction of ET-1 and NO.

Murine study of portal hypertension associated endothelin-1 hypo-response

AIM:To investigate endothelin-1 hypo-responsive associated with portal hypertension in order to improve patient treatment outcomes.METHODS:Wild type,e NOS-/-and i NOS-/-mice receivedpartial portal vein ligation surgery to induce portal hypertension or sham surgery.Development of portal hypertension was determined by measuring the splenic pulp pressure,abdominal aortic flow and portal systemic shunting.To measure splenic pulp pressure,a microtip pressure transducer was inserted into the spleen pulp.Abdominal aortic flow was measured by placing an ultrasonic Doppler flow probe around the abdominal aorta between the diaphragm and celiac artery.Portal systemic shunting was calculated by injection of fluorescent microspheres in to the splenic vein and determining the percentage accumulation of spheres in liver and pulmonary beds.Endothelin-1 hypo-response was evaluated by measuring the change in abdominal aortic flow in response to endothelin-1 intravenous administration.In addition,thoracic aorta endothelin-1contraction was measured in 5 mm isolated thoracic aorta rings ex-vivo using an ADI small vessel myograph.RESULTS:In wild type and i NOS-/-mice splenic pulp pressure increased from 7.5±1.1 mm Hg and 7.2±1 mm Hg to 25.4±3.1 mm Hg and 22±4 mm Hg respectively.In e NOS-/-mice splenic pulp pressure was increased after 1 d(P=NS),after which it decreased and by 7 d was not significantly elevated when compared to 7 d sham operated controls(6.9±0.6 mm Hg and 7.3±0.8 mm Hg respectively,P=0.3).Abdominal aortic flow was increased by 80%and 73%in 7 d portal vein ligated wild type and i NOS when compared to shams,whereas there was no significant difference in 7 d portal vein ligated e NOS-/-mice when compared to shams.Endothelin-1 induced a rapid reduction in abdominal aortic blood flow in wild type,e NOS-/-and i NOS-/-sham mice(50%±8%,73%±9%and 47%±9%respectively).Following portal vein ligation endothelin-1 reduction in blood flow was significantly diminished in each mouse group.Abdominal aortic flow was reduced by 19%±9%,32%±10%and 9%±9%in wild type,e NOS-/-and i NOS-/-mice respectively.CONCLUSION:Aberrant endothelin-1 response in murine portal hypertension is NOS isoform independent.Moreover,portal hypertension in the portal vein ligation model is independent of ET-1 function.

Taurine protects against retinal and optic nerve damage induced by endothelin-1 in rats via antioxidant effects

Endothelin-1（ET-1）, a potent vasoconstrictor, is involved in retinal vascular dysregulation and oxidative stress in glaucomatous eyes. Taurine（TAU）, a naturally occurring free amino acid, is known for its neuroprotective and antioxidant properties. Hence, we evaluated its neuroprotective properties against ET-1 induced retinal and optic nerve damage. ET-1 was administered intravitreally to Sprague-Dawley rats and TAU was injected as pre-, co-or post-treatment. Animals were euthanized seven days post TAU injection. Retinae and optic nerve were examined for morphology, and were also processed for caspase-3 immunostaining. Retinal redox status was estimated by measuring retinal superoxide dismutase, catalase, glutathione, and malondialdehyde levels using enzyme-linked immuosorbent assay. Histopathological examination showed significantly improved retinal and optic nerve morphology in TAU-treated groups. Morphometric examination showed that TAU pre-treatment provided marked protection against ET-1 induced damage to retina and optic nerve. In accordance with the morphological observations, immunostaining for caspase showed a significantly lesser number of apoptotic retinal cells in the TAU pre-treatment group. The retinal oxidative stress was reduced in all TAU-treated groups, and particularly in the pre-treatment group. The findings suggest that treatment with TAU, particularly pre-treatment, prevents apoptosis of retinal cells induced by ET-1 and hence prevents the changes in the morphology of retina and optic nerve. The protective effect of TAU against ET-1 induced retinal and optic nerve damage is associated with reduced retinal oxidative stress.

Endothelin-1-induced mini-stroke in the dorsal hippocampus or lateral amygdala results in deficits in learning and memory

Functional and structural alterations in brain connectivity associated with brain ischemia have been extensively studied. However, the mechanism whereby local ischemia in deep brain region affect brain functions is still unknown. Here, we first established a mini-stroke model by infusion of endothelin-1 （ET-1） into the dorsal hippo- campus or the lateral amygdala, and then investigated how these mini-infarcts affected brain functions associated with these regions. We found that rats with ET-1 infusion showed deficit in recall of contextual fear memory, but not in learning process and recall of tone fear memory. In novel object task, ET-1 in the hippocampus also elimi- nated object identity memory. ET-1 in the lateral amygdale affected acquisition of fear conditioning and disrupted retention of tone-conditioned fear, but did not impair retention of contextual fear. These findings suggest that ET-1- induced mini-infarct in deep brain area leads to functional deficits in learning and memory associated with these regions.

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.

Molecular determinants of the profibrogenic effects of endothelin-1 in pancreatic stellate cells

AIM： To gain molecular insights into the expression and functions of endothelin-1 （ET-1） in pancreatic stellate cells （PSC）.METHODS： PSCs were isolated from rat pancreas tissue, cultured, and stimulated with ET-1 or other extracellular mediators. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2＇-deoxyuridine into DNA and cell migration was studied in a transwell chamber assay. Gene expression at the level of mRNA was quantified by real-time Polymerase chain reaction. Expression and phosphorylation of proteins were monitored by immunoblotting, applying an infrared imaging technology. ET-1 levels in cell culture supernatants were determined by an enzyme immunometric assay. To study DNA binding of individual transcription factors, electrophoretic mobility shift assays were performed.RESULTS： Among several mediators tested, transforming growth factor-β1 and tumour necrosis factor-α displayed the strongest stimulatory effects on ET-1 secretion. The cytokines induced binding of Smad3 and NF-κB, respectively, to oligonucleotides derived from the ET-1 promoter, implicating both transcription factors in the induction of ET-1 gene expression. In accordance with previous studies, ET-1 was found to stimulate migration but not proliferation of PSC. Stimulation of ET-1 receptors led to the activation of two distinct rnitogen-activated protein kinases, p38 and extracellular signal-regulated kinases （ERK）1/2, as well as the transcription factor activator protein-1. At the mRNA level, enhanced expression of the PSC activation marker, α-smooth muscle actin and two proinflammatory cytokines, interleukin （IL）-1β and IL-6, was observed. CONCLUSION： This study provides novel lines of evidence for profibrogenic and proinflammatory actions of ET-1 in the pancreas, encouraging further studies with ET-1 inhibitors in chronic pancreatitis.

Comparison of p38 MAPK, soluble endoglin and endothelin-1 level in severe preeclampsia and HELLP syndrome patients

Objective: To compare the levels of p38 mitogen-activated protein kinase (MAPK), soluble endoglin and endothelin-1 in the serum of patients with severe preeclampsia, hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome and normal pregnancies. Methods: This study was an observational analytic cross-sectional study performed at Wahidin Sudirohusodo Hospital, Makassar, Indonesia, in the period of 5th February 2016 to 20th January 2017. P38 MAPK, soluble endoglin and endothelin-1 levels of patients with normal pregnancies, severe preeclampsia and HELLP syndrome were measured by enzyme-linked immunoabsorbentassay technique, using kits of human soluble endoglin, endothelin-1 and p38 MAPK, Quantikine immunoassay: R&D System Inc. Results: Level of serum p38 MAPK in HELLP syndrome group was higher than in severe preeclampsia and normal pregnancy groups. Soluble endoglin and endothelin-1 levels in pregnancies with severe preeclampsia and HELLP syndrome were higher than normal pregnancy but there was no significant difference between these two groups (P>0.05). Levels of p38 MAPK, soluble endoglin and endothelin-1 also had a positive linear correlation with systolic and diastolic blood pressures (P<0.05). Conclusions: P38 MAPK in serum may be a marker for evidence of the severe hypoxia and its application may be considered for the diagnosis of HELLP syndrome.

Plasma big endothelin-1 is an effective predictor for ventricular arrythmias and end-stage events in primary prevention implantable cardioverter-defibrillator indication patients

Objective To investigate whether plasma big endothelin-1(ET-1) predicts ventricular arrythmias(VAs) and end-stage events in primary prevention implantable cardioverter-defibrillator(ICD) indication patigents. Methods In total, 207 patients fulfilling the inclusion criteria from Fuwai Hospital between January 2013 and December 2015 were retrospectively analyzed. The cohort was divided into three groups according to baseline plasma big ET-1 tertiles: tertile 1(< 0.38 pmol/L, n = 68), tertile 2(0.38–0.7 pmol/L, n = 69), and tertile 3(> 0.7 pmol/L, n = 70). The primary endpoints were VAs. The secondary endpoints were end-stage events comprising all-cause mortality and heart transplantation. Results During a mean follow-up period of 25.6 ± 13.9 months, 38(18.4%) VAs and 78(37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class(r = 0.165, P = 0.018), serum creatinine concentration(Scr;r = 0.147, P = 0.034), high-sensitivity C-reactive protein(hs-CRP;r = 0.217, P = 0.002), Lg NT-pro BNP(r = 0.463, P < 0.001), left ventricular end diastolic diameter(LVEDD;r = 0.234, P = 0.039) and negatively correlated with left ventricular ejection fraction(LVEF;r =-0.181, P = 0.032). Kaplan-Meier analysis showed that elevated big ET-1 was associated with increased risk of VAs and end-stage events(P < 0.05). In multivariate Cox regression models, big ET-1 was an independent risk factor for VAs(hazard ratio(HR) = 3.477, 95% confidence interval(CI): 1.352–8.940, P = 0.010, tertile 2 vs. tertile 1;HR = 4.112, 95% CI: 1.604–10.540, P = 0.003, tertile 3 vs. tertile 1) and end-stage events(HR = 2.804, 95% CI: 1.354–5.806, P = 0.005, tertile 2 vs. tertile 1;HR = 4.652, 95% CI: 2.288–9.459, P < 0.001, tertile 3 vs. tertile 1). Conclusions In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.

Endogenous Endothelin-1 Regulates Hypoxia-Induced Atrial Natriuretic Peptide Secretion by Activating the MAPK/ERK and PI3K/Akt Signaling Pathways in Isolated Beating Rabbit Atria

The present study investigated a possible mechanism for endogenous endothelin-1 (ET-1) regulation of atrial natriuretic peptide (ANP) secretion in isolated perfused acute hypoxic rabbit atria. Acute hypoxia significantly enhanced the release of ET-1 and the expression of the ET receptor (ETR) type A and B (ETRA and ETRB) in atrial tissues, with a concomitant increase in ANP secretion. The ETRA or ETRB antagonist, BQ123 (0.3 μmol/L) or BQ788 (0.3 μmol/L), respectively attenuated hypoxia-induced ANP secretion. Both antagonists significantly attenuated the levels of hypoxiainduced atrial phosphorylated (p)-extracellular signal-regulated kinase (ERK) and p-protein kinase B (Akt). The ERK and Akt inhibitors, PD098059 (30 μmol/L) and LY294002 (30 μmol/L), respectively mimicked the effect of the ETR antagonists. These results demonstrated that acute hypoxia- mediated atrial ET-1 regulated ANP secretion through ETR and the subsequent mitogenactivated protein kinase (MAPK)/ERK and ETR-phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways. These pathways may mediate atrial endocrine functions under hypoxic conditions.

Effect of acupuncture on the genetic expression of myocardial endothelin-1 and atrial natriuretic peptide in rats with stress-induced prehypertension

Objective:To explore the protective effect of acupuncture against myocardial injury in rats with stress-induced prehypertension (SIPH) by observing the genetic expression of myocardial endothelin-1 (ET-1) and atrial natriuretic peptide (ANP).Methods:Thirty-six Wistar rats were randomized into three groups:the control group,model group,and model + acupuncture (AP) group (n =12 rats per group).During the 11-day modeling period,the model group and the model + AP group experienced plantar electric stimulation in combination with noise exposure,and daily acupuncture intervention was applied simultaneously in the model + AP group;the control group did not experience modeling or acupuncture.Systolic pressure (SP) was measured the day before modeling began,and on the 3rd,5th,7th,9th,and 11th day after modeling initiation.On the 12th day,histopathological observation of the left ventricle was made with hematoxylin-eosin staining and quantitative genetic expression of myocardial ET-1,and ANP was tested by quantitative real-time polymerase chain reaction (PCR).Results:SP was higher in the model group than the control group on the 3rd,5th,7th,9th,and 11th days (all P <.01).SP in the model + AP group was lower than that in the control group on the 5th and 7th days (respectively,P =.008,P =.002) and on the 9th and 11th days (P =.029,P =.039).Hematoxylin-eosin staining showed normal myocardial cellular structure in the control group.The model group showed disordered arrangement of cardiac cells with morphological changes in some nuclei,including enlargement or dissolution;there was also infiltration of inflammatory cells and proliferation of collagen fibers.In the model + AP group,most of the myocardial cells were normally structured,and only part of the cells had morphological changes with enlarged nuclei or dissolution.Real-time PCR showed that expression of ET-1 and ANP mRNA in the model group was greater than the control group (respectively,P =.024,P =.000101).The model + AP group had lower expression of ET-1 and ANP mRNA compared with the model group (respectively,P =.033,P =.043).Conclusion:Acupuncture may lower blood pressure and downregulate the genetic expression of myocardial ET-1 and ANP in SIPH rats,suggesting a protective effect of acupuncture against myocardial damage.

Correlating plasma endothelin-1 and beta-endorphin levels to nine risk factors of acute cerebral infarction

BACKGROUND： Several studies have confirmed that endothelin and endorphin are involved in the occurrence of cerebral vasospasm. However, the correlation of these factors to acute cerebral infarction-related risk factors needs to be confirmed. OBJECTIVE： To detect endothelin-1 （ET-1） and beta-endorphin （β -EP） levels in plasma of patients with acute cerebral infarction, and to analyze the correlations of these factors to smoking, alcohol abuse, hypertension, diabetes mellitus, diseased region, diseased degree, gender, and other factors related to acute cerebral infarction. DESIGN： A case-control observation. SETTING： First Department of Neurology, Guangdong Hospital of Traditional Chinese Medicine; Department of Neurology, Second Affiliated Hospital of Sun Yat-sen University. PARTICIPANTS： Sixty-nine inpatients with acute cerebral infarction were admitted to the Department of Neurology, Second Affiliated Hospital of Sun Yat-sen University （March 2003-January 2004） and First Department of Neurology, Guangdong Hospital of Traditional Chinese Medicine （March July 2004） and recruited for this study. All 69 inpatients corresponded to the diagnosis criteria of acute cerebral infarction, formulated in the National Working Conference of Cerebrovascular Disease in 1998, and were confirmed as acute cerebral infarction by CT/MRI. The patient group consisted of 35 males [（644- 12） years old] and 34 females[ （674- 13 ） years old]. Among them, 9 patients were smokers, 7 were alcohol users, 48 had a history of hypertension, and 16 had a history of diabetes mellitus. CT/MRI examinations revealed that 35 patients presented with left focus sites, 11 with right ones and 23 with bilateral ones. Following attack, 24 patients had Barthel Index Scale grading 〈 40 points, 21 patients 40-50 points, and 24 patients 〉 60 points. An additional 59 healthy individuals, who received health examinations simultaneously, were included as controls. Among the control subjects, there were 37 males [（62±10） years old] and 22 females [（65±11） years old]. Among them, 7 patients were smokers, and 6 were alcohol users. All controls had no history of stroke, hypertension, or diabetes mellitus. Informed consents of laboratory measurements were obtained from all subjects, and this study was approved by the Hospital Ethics Committee. METHODS： ① Following admission, all subjects were scored by Barthel Index Scale （BIS） and Hamilton Depression Scale. Meanwhile, hypertension, diabetes mellitus, gender, smoking, drinking, and other conditions were recorded. CT/MRI examination was conducted to identify the focus site.②On the 2^nd day after admission, ET-1 and β -EP plasma levels were measured with an automatic ET-1 and β -EP analysis kit. MAIN OUTCOME MEASURES： ET-1 and β -EP plasma levels and their correlation to acute cerebral infarction-related factors. RESULTS： Sixty-nine patients with acute cerebral infarction, and an additional 59 healthy individuals participated in the final analysis. β ET-1 [（63.80±27.65） ng/L vs. （46.50±9.36） ng/L, P 〈 0.05] and β - EP [（94.18±33.94） mg/L vs. （51.87±23.43） mg/L, P 〈 0.05] levels of the patient group were obviously higher than respective values of the control group. ② The ET-1 and β -EP levels of patients with cerebral infarction did not correlate to hypertension, diabetes mellitus, BIS, depression, cerebral infarct focus, disease course, gender, smoking or drinking （P 〉 0.05）. CONCLUSION： The ET-I and β-EP levels of patients with acute cerebral infarction increased, but they were not obviously associated with disease course, blood pressure, blood glucose, BIS, or other common cerebral infarction-related factors.

Response of blood endothelin-1 and nitric oxide activity in duodenal ulcer patients undergoing Helicobacter pylori eradication

AIM: To investigate the effect of Helicobacter pylori eradication on endothelin-1 (ET-1) and nitric oxide (NO) in duodenal ulcer (DU) patients. METHODS: Sixty-six Hpylori-infected active DU patients were consecutively enrolled to receive one-week triple therapy (rabeprazole, amoxicillin and metronidazole) and then one-month rabeprazole therapy. They were asked back to determine ulcer and Hpylori status using endoscopy one month later. Thirty-seven healthy controls (H pylori +/-:17/20) were enrolled for comparison. Blood samples were collected in each visit to measure plasma ET-1 and nitrate/nitrite levels using an enzyme immunoassay kit. RESULTS: Sixty DU patients finished trial per protocol. The ulcer healing and Hpylori-eradication rates were 86.7% and 83.3%, respectively. Plasma ET-1 level in DU patients was higher than that of Hpylori-negative and positive controls (3.59±0.96 vs0.89±0.54 vs0.3±0.2 pg/mL,P<0.01), while nitrate/nitrite levels among them were also significantly different (8.55±0.71 vs5.27±0.68 vs 6.39±0.92 μmol/L, P<0.05). H pylori eradication diminished ET-1 levels (3.64±0.55 vs2.64±0.55 pg/mL, P<0.01) but elevated nitrate/ nitrite level (8.16±0.84 vs11.41±1.42 umol/L,P<0.05). CONCLUSION: Both plasma ET-1 and nitrate/nitrite levels increase in active DU patients. After an effective H pylori eradication, DU healing is associated with diminished blood ET-1 level and elevated nitrate/nitrite level.