Endothelin receptor antagonists for the treatment of diabetic nephropathy:A meta-analysis and systematic review

BACKGROUND Diabetic nephropathy(DN)is the main cause of chronic kidney disease and endstage renal disease worldwide.Although available clinical trials have shown that endothelin receptor(ER)antagonists may be a novel and beneficial drug for DN,no consistent conclusions regarding their sufficient effectiveness and safety for patients with DN have been presented.AIM To assess the effectiveness and safety of ER antagonists among patients with DN.METHODS The EMBASE,PubMed,MEDLINE,Cochrane,and ClinicalTrials.gov databases were searched without any language restrictions.Relative risks with 95%confidence intervals(CIs)for dichotomous data and mean differences or standardized mean difference with 95%CIs for continuous data were calculated using Review Manager 5.3 software.Publication bias was assessed using Egger’s test with Stata/SE software.RESULTS We enrolled seven studies with six data sets and 5271 participants.The ER antagonists group showed a significantly greater reduction in albuminuria and more patients with 40%reduction in urinary albumin-to-creatinine ratio than the control group(P<0.0001 and P=0.02,respectively).Subgroup analysis for reductions in estimated glomerular filtration rate(eGFR)showed that for the middle-dosage subgroup,the ER antagonists group exhibited lower eGFR reduction than the control group(P<0.00001;mean difference,0.7095%CI:0.66,0.74).Moreover,significant reductions in systolic and diastolic blood pressure were observed in the invention group.CONCLUSION ER blockades combined with angiotensin converting enzyme inhibitor/angiotensin II type 1 receptor blockers may be an effective treatment to lower blood pressure and reduce proteinuria in DN with declined eGFR.However,attention should be given to adverse events,including cardiac failure,anemia,and hypoglycemia,as well as serious adverse events.

Correlation between Pulmonary Endothelin Receptors and Alveolar-arterial Oxygen Gradient in Rats with Hepatopulmonary Syndrome

The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient （A aDO2） in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups： Sham operated （Sham） group and common bile duct ligation （CBDL） group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined by in situ hybridization. The results showed that the level of A aDO2, was higher in CBDI. group than that in Sham group （P〈0.05）. The levels of plasma and pulmonary ET-1 in CBDL group were both higher than in Sham group （P〈0.05 ）. There was no significant difference in average A of ETRA between two groups by imaging analysis （0.21±0.06 vs 0.22±0.08, P〉0.05）, while that of ETRB was higher in CBDI. group than in Sham group （0.58±0.16 vs 0.28±0.07, P〈0.05）. The expression of ETRBinlung was positively correlated with A aDO2（P〈0.05）. It was concluded that the widened A-aDO2 may be related with enhancement of the expression of ETRB in lung.

Correlation of calcitonin gene-related peptide and endothelin receptor A with subarachnoid hemorrhage

Numerous studies have demonstrated that endothelin-1 combines with endothelin receptor A, resulting in intense vasoconstriction. Although calcitonin gene-related peptide （CGRP） suppresses endothelin-1, CGRP and endothelin receptor A exhibit direct biological effects on brain tissue. The present study analyzed CGRP and endothelin receptor A expression following subarachnoid hemorrhage in rabbits using immunohistochemistry. CGRP expression was significant at 5 days after model establishment, and endothelin receptor A expression was significant at 3 days after model induction. The perimeter of the basilar artery was measured to determine the amount of cerebral vasospasm. Analytical results revealed a significantly shortened basilar artery perimeter following subarachnoid hemorrhage. Changes in the basilar artery perimeter were negatively associated with endothelin receptor A expression, but positively correlated with CGRP expression in vessels. These results suggest that following subarachnoid hemorrhage, CGRP and endothelin receptor A expressions dynamically changed in brain vessels and tissues, although these changes were not synchronous. Changes in endothelin receptor A expression exhibited a significant effect on the occurrence and development of delayed cerebral vasospasm and delayed neuronal death, while CGRP relaxed vessels and protected nerves.

Increased Expression of Endothelin Receptors in Human Cirrhosis—— Relationship with Splanchnic Hemodynamics

The purpose of the present study was to assess the correlation that likely exists among increased portal pressure (P p), portal blood flow quantity (Q p) and ET A and ET B receptor mRNA expression in human cirrhosis. In situ hybridization and reverse transcription polymerase chain reactions (RT PCR) were performed to determine the expression of ET A and ET B receptor mRNA in liver tissues from traumatic subjects ( n =10) and cirrhotic patients ( n =15) in whom hepatic hemodynamic values were measured. The expression of the two transcripts was significantly higher in liver samples of cirrhotic patients than in those obtained from traumatic subjects. It has shown that ET A receptor mRNA predominantly located in hepatic stellate cells (HSCs) and vascular smooth muscle cells of intrahepatic arteries and portal veins, ET B receptor mRNA in HSCs, sinusoidal endothelial cells and Kuppfer cells. There was a highly significant direct relationship between ET A and ET B receptor mRNA and P p and Q p in cirrhotic patients. It suggests that liver paracrine endothelin system may be overactivated in human cirrhosis accompanied with increased expression of ET A and ET B receptor mRNA which may play an important role in the pathogenesis and maintenance of splanchnic hyperdynamics.

The Expression of Endothelin Receptor B in Melanoma Cells A375 and Sk-mel-1 and the Proliferative Effects of Endothelin 3 on A375 Cells

In order to investigate the expression of endothelin receptor B （ETR-B） in human malignant melanoma （MM） cells A375 and SK-mel-1 and the proliferative effects of endothelin 3 （ET3） on A375 cells, RT-PCR was applied to detect the expression of ETR-B gene in human MM cells A375 and SK-mel-1. MTT method was used to evaluate the growth enhancing effects of ET3 on A375 cell line in vitro. The results showed that ETR-B gene was expressed in both MM A375 and SK-mel-1 cells. ET3 had stronger ability to enhance the proliferation of A375 cells in vitro in a concentration-dependent manner. It was suggested that ET3/ETR-B might play an important proliferative role in MM.

Synthesis and Crystal Structure of an Endothelin Receptor Antagonist Ambrisentan

The title compound was synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic system （C22H22N2O4, Mr = 378.42）, space group P2121 with a = 6.8786（12）, b = 14.259（2）, c = 19.712（3） A, V= 1933.5（6） A3, Z = 4, Dc = 1.300 g/cm3, f（000） = 800, μ= 0.090 mm-1, the final R = 0.0324 and wR = 0.0775 for 2410 observed reflections （I 〉 2σ（I））. The structure, especially the absolute configuration, of the title compound ambrisentan, an important endothelin receptor antagonist, was confirmed by single- crystal X-ray diffraction. The three aromatic rings in the lattice are basically orthogonal to one another. There is an intermolecular hydrogen bond in the crystal, which helps to further stabilize the crystal. One of the two non-classical intramolecular hydrogen bonds can help to stabilize the molecular conformation in the lattice.

EFFECT OF ANGIOTENSIN II RECEPTOR ANTAGONIST AND ENDOTHELIN RECEPTOR ANTAGONIST ON NITROGLYCERIN TOLERANCE IN RATS

Objective. To investigate whether angiotensin II receptor antagonist and endothelin receptor antagonist can improve the nitroglycerin (Nit) tolerance in vivo. Methods. Twenty- four rats were divided into 4 groups (n=6,each): Control group, Nitroglycerin (Nit) group, Nit＋ bosentan group and Nit＋ losartan group. Nitroglycerin tolerance was induced by 2- day treatment of nitroglycerin patch (0.05 mg/h). AngiotensinⅡ receptor antagonist losartan ( 10 mg· kg－ 1· d－ 1 ) and endothelin receptor antagonist bosentan ( 100 mg· kg－ 1· d－ 1 ) were given by gavage for 2 days respectively. Results. The least hypotensive response to sodium nitroprusside (SNP) was observed in Nit group . The effective percentages of hypotensive response to SNP were increased in both Nit＋ losartan group and Nit＋ bosentan group compared with Nit group [(31.95± 4.45 )％ vs (21.00± 3.69 )％ , P< 0.01 and (33.18± 6.16 )％ vs (21.00± 3.69 )％ , P< 0.01 ,respectively]. The maximal vessel relaxation induced by SNP was the same in 4 different groups but the highest EC50 (concentration which produces 50％ of the maximal response to SNP) was found in tolerant group[(34± 10) nmol/ L,P < 0.01 .The ET- 1 amounts in plasma and vascular tissue were markedly increased by 54％ and 60％ in Nit group compared with those in control group(P< 0.01).The ET- 1 amounts in plasma and vascular tissue were decreased by 30％ and 37％ in Nit＋ losartan group compared with those in Nit group (P< 0.01). Conclusion. Endothelin receptor antagonist and angiotensinⅡ receptor antagonist could prevent against the Nit tolerance .

Effects of endotoxin on endothelin receptor in hepatic and intestinal tissues after endotoxemia in rats

INTRODUCTIONEndothelins(ETs) has a potent and sustainedvasoconstrictive effect on a variety of blood vessels.The vascular smooth muscle cell (VSMC)is thetarget for ETs.VSMC of the whole body containsendothelin receptor (ETR).A great number ofexperiments have shown that three distinctcomplementary DNAs of ETR have been identifiedi.e.,endothelin A receptor(ET_A receptor),endothelin B receptor(ET_B receptor)

Increased endothelin receptor B and G protein coupled kinase-2 in the mesentery of portal hypertensive rats

AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.

Therapeutic Trial of an Endothelin Receptor Agonist for the Highly Pathogenic Avian Influenza A/H5N1 Virus Infection in Chicks

The rapid spread of the highly pathogenic A/H5N1 avian influenza virus among domestic birds and its transmission to humans has induced world-wide fears of a new influenza pandemic. A/H5N1 has infected over 300 people since 1997, and has shown a mortality rate of over 50%. The high mortality in human cases is thought to be enhanced by the excessive secretion of various endogenous factors, including cytokines and interleukins, stimulated by viral infections. Chickens infected with A/H5N1 viruses experience sudden death without showing severe clinical symptoms or inflammation. However, severe hemorrhage and congestion are seen in various tissues in sporadic chicken cases of A/H5N1-infections, especially in the pulmonary tissues, thus indicating that there is ischemia due to vascular abnormalities. Our previous studies have focused on the expression pattern of endothelin-1, which modulates the vascular tone via endothelin receptors. An Indonesian sporadic strain of A/H5N1 virus was intranasally administered to 10-day-old chicks, and the expression of endothelin was examined in the infected birds. All birds died within five days of inoculation, and had moderate inflammation accompanied by severe hemorrhage and congestion in the lungs. Immunohistochemical studies showed enhanced expression of endothelin-1 in the infected lungs. In addition, the real-time PCR analyses revealed that endothelin-1 and endothelin receptor A mRNA were significantly elevated in the birds with A/H5N1 infections. Subsequently, H5N1-infected birds were inoculated with bosentan hydrate, a competitive antagonist of endothelin receptors. Interestingly, the mortality rate of the infected birds was dramatically decreased in a dose-dependent manner by the administration of bosentan hydrate. The pathological lesions, including congestion and hemorrhage in the pulmonary tissues, were clearly inhibited. These findings are promising, and suggest that endothelin receptor antagonists are a potential treatment for the highly pathogenic avian flu.

Semi-quantitatively Predicting the Residence Time of Three Natural Products on Endothelin Receptor A by Peak Profiling Using the Receptor Functionalized Macroporous Silica Gel as Stationary Phase

Drug-receptor interaction analysis has been broadly adopted as a tool for the evaluation of the drug-like property.Nowadays,growing evidence has demonstrated that drug e fficacy and safety are highly related to residence time,which equals the reciprocal of the dissociation rate constant(k_(d))of a drug to its target protein.Using endothelin receptor A(ET_(A)R)as a probe,we immobilized the receptor on the surface of macroporous silica gel through a covalent interaction between the epidermal growth factor tyrosine kinase(EGFR)at the C terminal of ET_(A)R and the covalent inhibitor ibrutinib modified on the gel in a one-step fashion.The a ffinity stationary phase was used to semi-quantitatively determine the residence time of natural products on ET_(A)R and evaluate their drug-like property.The k_(d)values of three specific ligands(bosentan,macitentan,and ambrisentan)to ET_(A)R were determined by nonlinear chromatography,peak profiling and peak_(d)ecay.Compared the data determined in free solution of the three methods,peak profiling is considered as the best-fit method for k_(d)determination.Thus,peak profiling was applied for predicting the residence time of three natural products(ferulic acid,berberine,and palmatine)on ET_(A)R.With the longest residence time of 61.11±3.47 s on ET_(A)R,palmatine was evaluated as the most potent compound,which could be developed as a long-acting lead for the receptor.We demonstrate that the high-performance a ffinity chromatography with immobilized ET_(A)R is an alternative for the semi-quantitative measurement of residence time for the drug-like property evaluation of natural products.

MUTATION OF THE ENDOTHELIN-B RECEPTOR AND THE ENDOTHELIN-3 GENE IN CHINESE SPORADIC CASES OF HIRSCHSPRUNG'S DISEASE

Objective To investigate the mutation of endothelin receptor B (EDNRB) gene and endothelin 3 (EDN 3) gene in sporadic Hirschsprungs disease (HD) in Chinese population. Methods Genomic DNA was extracted from bowel tissues of 34 unrelated HD patients which were removed by surgery. Exon 3, 4, 6 of EDNRB gene and Exon 1, 2 of EDN 3 gene were amplified by polymerase chain reaction (PCR) and analyzed by single strand conformation polymorphism (SSCP).Results EDNRB mutations were detected in 2 of the 13 short segment HDs. One mutant was in the exon 3; the other one was in the exon 6. EDN 3 mutation was detected in 1 of the 13 short segment HDs and in the exon 2. Both EDNRB mutation and EDN 3 mutation were detected in one short segment HD. No mutations were detected in the ordinary or long segment HD. Conclusion The mutations of EDNRB gene and EDN 3 gene are found in the short segment HD of sporadic Hirschsprung's disease in Chinese population, which suggests that the EDNRB gene and EDN 3 gene play important roles in the pathogenesis of HD. the mutations of EDNRB and EDN 3 lead to the maldevelopment of the enteric nervous system.

INTRACELLULAR REDISTRIBUTION OF CARDIAC ENDOTHELIN- 1 RECEPTOR IN RAT DURING MYOCARDIAL HYPERTROPHY

Objective. In a model of rat cardiac hypertrophy, the changes in the distribution of ET- 1 receptors in two subcellular fractions, the sarcolemma and the light vesicles during myocardial hypertrophy were studied. Methods. Cardiac hypertrophy was produced by placing a constricting clip around the suprarenal abdominal aorta of rats, and ET- 1 receptor was assayed with radioactive analysis method. Results. It was found that plasma and ventricular ET- 1 levels increased significantly on week 2 and week 4 of pressure overload. ET- 1 binding studies showed that during myocardial hypertrophy, the maximum binding capacity (Bmax) was increased by 41％ (P< 0.01) and 65％ (P< 0.01) in sarcolemma in H- 2 week and H- 4 week groups, but was decreased by 24％ (P< 0.01) and 21％ (P< 0.01) in light vesicles. The sum of Bmax of sarcolemmal and light vesicle fractions was increased by 33％ (P< 0.01) and 57％ (P< 0.01) in group H- 2 week and H- 4 week, respectively. Conclusion. ET- 1 receptors in rat heart were externalized from light vesicles to sarcolemma, which may contribute to the development of myocardial hypertrophy.

Endothelin receptor antagonist combined with a calcium channel blocker attenuates renal injury in spontaneous hypertensive rats with diabetes

OBJECTIVE: To investigate the effects of the mixed endothelin receptor antagonist, bosentan, combined with the long-acting calcium channel blocker, amlodipine, compared to the angiotensin-converting enzyme inhibitor, cilazapril, on the progressive renal injury in spontaneous hypertensive rats (SHR) with diabetes. METHODS: Diabetic hypertensive rats (SHR-DM) were induced by streptozotozin injected in male SHR (7-week-old),and divided into an untreated and three treated groups: 1) cilazapril treated group; 2) bosentan+amlodipine treated group; and 3) amlodipine treated group. Wistar Kyoto rats (WKY) and SHR rats served as normotensive and hypertensive control, respectively. The mean arterial blood pressure, renal function, endothelin and angiotensin II levels as well as the protein expression of renal extracellular matrix components and transforming growth factor (TGF)-beta1 were determined at the end of the 4th week. RESULTS: Mean arterial blood pressure significantly increased in SHR and SHR-DM rats compared to WKY rats. All the therapies reduced the blood pressure to normal levels. However, the enhanced urinary protein excretion, the decreased creatinine clearance as well as the increased plasma and intrarenal endothelin and angiotens in II levels were found in the untreated SHR-DM and prevented by treatment with bosentan+amlodipine and cilazapril. Similarly, these two kinds of therapies in SHR-DM abolished the overexpression of renal TGF-beta1 by Western blot analysis and reduced the accumulation of collagen type IV, laminin and fibronectin proteins by an immunochemical approach. Amlodipine monotherapy had no detectable effects on the above parameters. CONCLUSION: Bosentan combined with amlodipine can offer similar renoprotective effects on that of cilazapril and may be a potent therapy to attenuate renal injury by reducing renal protein levels of TGF-beta1 in diabetes with a hypertensive state.

Externalization and internalization of cardiac endothelin receptors during different phases of sepsis in rat

Objective To study the redistribution of ET1 receptors in two subcellular organelles, the sarcolemmal membrane and the light vesicle, of rat heart during the progress of septic shock Methods Male Sprague Dawley rats weighing from 270 to 320?g were randomly divided into three groups: control, early sepsis, and late sepsis Each group included six rats Sepsis was induced by cecal ligation and puncture (CLP) Control rats were sham operated After operation for 9 hours or 18 hours, animals of the three groups were anesthetized with sodium pentobarbital (60?mg/kg IP) and the hearts were removed for preparation of sarcolemma and light vesicle Hemodynamic parameters were determined with polygraph via femoral artery and intraventricular cannula ET1 receptor was assayed by [ 125 I] ET1 binding Results Heart rate, cardiac output and left ventricular +dp/dt max undergo biphasic changes: an increase in early phase of sepsis (9?h after CLP) followed by a decrease in late phase of sepsis (18?h after CLP) Mean arterial blood pressure and left ventricular dp/dt max remained relatively unaltered during early phase of sepsis but was decreased during late phase of sepsis Although septic rat heart exhibited biphasic cardiodynamic changes, myocardial function showed signs of progressive deterioration during the development of sepsis, as indicated by a progressive elevation of LVEDP [ 125 I] ET1 bindings to cardiac membranes exhibited a saturable process with a single component binding characteristic for all three experimental groups In sarcolemmal membrane fraction, the maximum binding capacity (B max ) calculated from scatchard plot was increased 30% ( P <0 01) during early phase of sepsis but decreased 24% ( P <0 01) during late phase of sepsis The affinity [the reciprocal of the dissociation contant (Kd)] for [ 125 I] ET1 binding in sarcolemmal membranes remained unaffected during early and late phases of sepsis In light vesicle fraction, the B max for [ 125 I] ET1 binding was decreased by 19% ( P <0 05) during early phase of sepsis but increased by 38% ( P <0 01) during late phase of sepsis The affinity for [ 125 I] ET1 binding in light vesicles was unaltered in early and late phases of sepsis It should be mentioned that the sum of Bmax of sarcolemmal and light vesicle fractions was increased by 25% ( P <0 01) during early phase of sepsis but was decreased by 17% ( P <0 01) during late phase of sepsis Conclusions These data indicated that a biphasic intracellular redistribution of ET1 receptor in the heart might contribute to the development of the initial hyperdynamic and subsequent hypodynamic state during sepsis

Study of the Effect of Leeching on Plasma Endothelin and Soluble Interleukin-2 Receptor in Patients with Systemic Lupus Erythematosus

Objective: to explore the mechanism of leeching in treating systemic lupus erythematosus (SLE). Methods: Forty-four patients with SLE were randomly divided into conventional corticosteroid treated group (control group, n =20) and conventional treatment group with leeching intervention added (leeching group, n =24). Before and after treatment the concentration of plasma endothelin (ET) and soluble interleukin-2 receptor (sIL-2R) were determined. Results: Before treatment the level of plasma ET and sIL-2R in the SLE patients were all higher than those in the normal healthy group, ( P <0.01). But after treatment the level of these in both groups were significantly improved than those of before treatment ( P <0.05), and comparison between these two treated groups showed that the difference between them was significant ( P <0.05). Conclusion: Leeching added to conventional treatment of SLE could be more effective in improving the level of plasma ET and sIL-2R, and ameliorating the impairment of renal tissues.

安立生坦治疗IgA肾病的疗效及安全性分析

目的探讨安立生坦作为选择性内皮素受体拮抗剂(endothelin receptor antagonist,ERA)在IgA肾病(IgA nephropathy,IgAN)患者中的疗效和安全性。方法收集北京大学第一医院肾内科2022年11月─2023年12月接受安立生坦治疗的IgA肾病患者的病历资料和随访数据,并在第4、8和12w时进行随访评估。研究的主要结果是随时间变化的24h尿蛋白、24h尿蛋白变化率、估算肾小球滤过率(estimate glomerular filtration rate,eGFR),同时监测药物的安全性。结果共纳入了147例IgA肾病患者。基线24h尿蛋白水平为1.16(0.74,1.99)g/d,安立生坦治疗后第4、第8、第12w的尿蛋白水平分别低于基线水平(Z=-8.157、-5.866、-5.238,均P<0.001)。在不同性别、eGFR分组、合并用药包括激素、免疫抑制剂、肾素-血管紧张素-醛固酮系统抑制剂(renin-angiotensin-aldosterone system inhibitor,RAASi)等亚组中,24h尿蛋白下降率无统计学差异(均P>0.05)。在12w随访期间,eGFR保持稳定。安立生坦在随访患者中耐受性良好,2例患者因水肿或肝功能损害停药。结论安立生坦可以降低IgA肾病患者尿蛋白且安全性良好。

马西替坦关键中间体5-(4-溴苯基)-4,6-二氯嘧啶的合成

以4-溴苯乙酸甲酯(Ⅱ)和碳酸二甲酯为原料,经克莱森(Claisen)缩合反应得到2-(4-溴苯基)-丙二酸-1,3-二乙酯(Ⅲ),化合物Ⅲ再与甲脒盐酸盐环合得到5-(4-溴苯基)嘧啶-4,6-二醇(Ⅳ),化合物Ⅳ经氯代反应得到目标化合物5-(4-溴苯基)-4,6-二氯嘧啶(Ⅰ);通过1 HNMR对中间体和目标化合物进行了表征,并对合成工艺进行了优化。^(1)HNMR分析结果表明,所得中间体和目标化合物均与目标物一致;在最优工艺条件下,3步总收率达到43.6%。该工艺原料廉价易得,反应条件温和,后处理简单,易于大规模工业化生产。

Gene expression profiling and endothelin in acute experimental pancreatitis

AIM:To analyze gene expression profiles in an experimental pancreatitis and provide functional reversal of hypersensitivity with candidate gene endothelin-1 antagonists.METHODS:Dibutyltin dichloride(DBTC) is a chemical used as a polyvinyl carbonate stabilizer/catalyzer,biocide in agriculture,antifouling agent in paint and fabric.DBTC induces an acute pancreatitis flare through generation of reactive oxygen species.Lewis-inbred rats received a single i.v.injection with either DBTC or vehicle.Spinal cord and dorsal root ganglia(DRG) were taken at the peak of inflammation and processed for transcriptional profiling with a cDNA microarray biased for rat brain-specific genes.In a second study,groups of animals with DBTC-induced pancreatitis were treated with endothelin(ET) receptor antagonists [ET-A(BQ123) and ET-B BQ788)].Spontaneous pain related mechanical and thermal hypersensitivity were measured.Immunohistochemical analysis was performed using anti-ET-A and ET-B antibodies on sections from pancreatic tissues and DRG of the T10-12 spinal segments.RESULTS:Animals developed acute pancreatic inflammation persisting 7-10 d as confirmed by pathological studies(edema in parenchyma,loss of pancreatic architecture and islets,infiltration of inflammatory cells,neutrophil and mononuclear cells,degeneration,vacuolization and necrosis of acinar cells) and the painrelated behaviors(cutaneous secondary mechanical and thermal hypersensitivity).Gene expression profile was different in the spinal cord from animals with pancreatitis compared to the vehicle control group.Over 260 up-regulated and 60 down-regulated unique genes could be classified into 8 functional gene families:circulatory/acute phase/immunomodulatory;extracellular matrix;structural;channel/receptor/transporter;signaling transduction;transcription/translation-related;antioxidants/chaperones/heat shock;pancreatic and other enzymes.ET-1 was among the 52 candidate genes upregulated greater than 2-fold in animals with pancreatic inflammation and visceral pain-related behavior.Treatments with the ET-A(BQ123) and ET-B(BQ-788) antagonists revealed significant protection against inflammatory pain related mechanical and thermal hypersensitivity behaviors in animals with pancreatitis(P < 0.05).Open field spontaneous behavioral activity(at baseline,day 6 and 30 min after drug treatments(BQ123,BQ788) showed overall stable activity levels indicating that the drugs produced no undesirable effects on normal exploratory behaviors,except for a trend toward reduction of the active time and increase in resting time at the highest dose(300 μmol/L).Immunocytochemical localization revealed that expression of ET-A and ET-B receptors increased in DRG from animals with pancreatitis.Endothelin receptor localization was combined in dual staining with neuronal marker NeuN,and glia marker,glial fibrillary acidic protein.ET-A was expressed in the cell bodies and occasional nuclei of DRG neurons in na ve animals.However,phenotypic expression of ET-A receptor was greatly increased in neurons of all sizes in animals with pancreatitis.Similarly,ET-B receptor was localized in neurons and in the satellite glia,as well as in the Schwann cell glial myelin sheaths surrounding the axons passing through the DRG.CONCLUSION:Endothelin-receptor antagonists protect against inflammatory pain responses without interfering with normal exploratory behaviors.Candidate genes can serve as future biomarkers for diagnosis and/or targeted gene therapy.

治疗难治性高血压的新药:aprocitentan

aprocitentan(商品名:Tryvio)是一种口服给药的靶向双重内皮素A/B受体(ETA/ETB)拮抗剂,2024年3月19日获美国食品药品监督管理局批准上市,与其他抗高血压药物联合用于治疗成人难治性高血压。该文通过对aprocitentan的作用机制、药物代谢动力学、临床研究、不良反应、特殊人群用药及注意事项的文献查阅,意在为临床治疗难治性高血压提供用药参考。