Mitochondrial Oxidative Stress Enhances Vasoconstriction by Altering Calcium Homeostasis in Cerebrovascular Smooth Muscle Cells under Simulated Microgravity

Objective Exposure to microgravity results in postflight cardiovascular deconditioning in astronauts.Vascular oxidative stress injury and mitochondrial dysfunction have been reported during this process.To elucidate the mechanism for this condition,we investigated whether mitochondrial oxidative stress regulates calcium homeostasis and vasoconstriction in hindlimb unweighted(HU)rat cerebral arteries.Methods Three-week HU was used to simulate microgravity in rats.The contractile responses to vasoconstrictors,mitochondrial fission/fusion,Ca^(2+) distribution,inositol 1,4,5-trisphosphate receptor(IP3 R)abundance,and the activities of voltage-gated K+channels(KV)and Ca^(2+)-activated K+channels(BKCa)were examined in rat cerebral vascular smooth muscle cells(VSMCs).Results An increase of cytoplasmic Ca^(2+) and a decrease of mitochondrial/sarcoplasmic reticulum(SR)Ca^(2+) were observed in HU rat cerebral VSMCs.The abundance of fusion proteins(mitofusin 1/2[MFN1/2])and fission proteins(dynamin-related protein 1[DRP1]and fission-mitochondrial 1[FIS1])was significantly downregulated and upregulated,respectively in HU rat cerebral VSMCs.The cerebrovascular contractile responses to vasoconstrictors were enhanced in HU rats compared to control rats,and IP3 R protein/mRNA levels were significantly upregulated.The current densities and open probabilities of KV and BKCa decreased and increased,respectively.Treatment with the mitochondrial-targeted antioxidant mitoTEMPO attenuated mitochondrial fission by upregulating MFN1/2 and downregulating DRP1/FIS1.It also decreased IP3 R expression levels and restored the activities of the KV and BKCa channels.MitoTEMPO restored the Ca^(2+) distribution in VSMCs and attenuated the enhanced vasoconstriction in HU rat cerebral arteries.Conclusion The present results suggest that mitochondrial oxidative stress enhances cerebral vasoconstriction by regulating calcium homeostasis during simulated microgravity.

Pinocembrin inhibits angiotensinⅡ-induced vasoconstriction in a Ca^(2+)-dependent and Ca^(2+)-independent manner through blocking AT_1R in the rat aorta

OBJECTIVE To investigate the vasorelaxant effect of pinocembrin(5,7-dihydroxyflavanone),one of the main flavonoids in propolis,on angiotensinⅡ(AngⅡ)induced vasoconstriction and the molecular mechanism of action.METHODS The isometric vascular tone was measured in thoracic aortic rings from SD rat,and the effects of pinocembrin on the single dose and concentration cumulative response curves of AngⅡ were recorded.The binding of pinocembrin to the angiotensin type 1 receptor(AT1R)was studied by using molecule docking analysis.Intracellular[Ca2+]([Ca2+]i)was measured with Fura2/AM in VSMCs.The phosphorylation levels of myosin light chain 2(MLC2)and myosin phosphatase target unit 1(MYPT1),and protein level of Rho kinase 1(ROCK1)in the rat aortic rings were detected by Western blotting.RESULTS Pinocembrin was observed to inhibit AngⅡ-induced vasoconstriction in rat aortic rings with either intact or denuded endothelium.In endothelium-denuded tissues,pinocembrin(pD′2 4.28±0.15)counteracted the contractions evoked by cumulative concentrations of AngⅡ.In a docking model,pinocembrin showed effective binding at the active site of AT1R.Pinocembrin was shown to inhibit both AngⅡ-induced Ca2+ release from internal stores and Ca2+ influx.Moreover,the increase in the phosphorylation of MLC2 and MYPT1,and the increased protein level of ROCK1 induced by AngⅡ was blocked by pinocembrin.CONCLUSION Pinocembrin inhibits AngⅡ-induced rat aortic ring contraction in a Ca2+-dependent and Ca2+-independent manner via blocking AT1R.

Tacrolimus Inhibits Vasoconstriction by Increasing Ca^(2+) Sparks in Rat Aorta

The present study attempted to test a novel hypothesis that Ca^2＋ sparks play an important role in arterial relaxation induced by tacrolimus. Recorded with confocal laser scanning microscopy, tacrolimus（10 μmol/L） increased the frequency of Ca^2＋ sparks, which could be reversed by ryanodine（10 μmol/L）. Electrophysiological experiments revealed that tacrolimus（10 μmol/L） increased the large-conductance Ca^2＋-activated K＋ currents（BKCa） in rat aortic vascular smooth muscle cells（AVSMCs）, which could be blocked by ryanodine（10 μmol/L）. Furthermore, tacrolimus（10 and 50 μmol/L） reduced the contractile force induced by norepinephrine（NE） or KCl in aortic vascular smooth muscle in a concentration-dependent manner, which could be also significantly attenuated by iberiotoxin（100 nmol/L） and ryanodine（10 μmol/L） respectively. In conclusion, tacrolimus could indirectly activate BKCa currents by increasing Ca^2＋ sparks released from ryanodine receptors, which inhibited the NE- or KCl-induced contraction in rat aorta.

Vasorelaxant effects of biochemical constituents of various medicinal plants and their benefits in diab

Endothelial function plays a pivotal role in cardiovascular health,and dysfunction in this context diminishes vasorelaxation concomitant with endothelial activity.The nitric oxide-cyclic guanosine monophosphate pathway,prostacyclin-cyclic adenosine monophosphate pathway,inhibition of phosphodiesterase,and the opening of potassium channels,coupled with the reduction of calcium levels in the cell,constitute critical mechanisms governing vasorelaxation.Cardiovascular disease stands as a significant contributor to morbidity and mortality among individuals with diabetes,with adults afflicted by diabetes exhibiting a heightened cardiovascular risk compared to their non-diabetic counterparts.A plethora of medicinal plants,characterized by potent pharmacological effects and minimal side effects,holds promise in addressing these concerns.In this review,we delineate various medicinal plants and their respective biochemical constituents,showcasing concurrent vasorelaxant and anti-diabetic activities.

The pivotal role of microglia in injury and the prognosis of subarachnoid hemorrhage

Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.

Vasorelaxant activity of extracts obtained from Apium graveolens:Possible source for vasorelaxant molecules isolation with potential antihypertensive effect

Objective:To investigate the vasorelaxant effect of organic extracts from Apium graveolens(A.graveolens)which is a part of a group of plants subjected to pharmacological and phytochemical study with the purpose of offering it as an ideal source for obtaining lead compounds for designing new therapeutic agents with potential vasorelaxant and antihypertensive effects.Methods:An ex vivo method was employed to assess the vasorelaxant activity.This consisted of using rat aortic rings with and without endothelium precontracted with norepinephrine.Results:All extracts caused concentration-dependent relaxation in precontracted aortic rings with and without endothelium;the most active extracts were Dichloromethane and Ethyl Acetate extracts from A.graveolens.These results suggested that secondary metabolites responsible for the vasorelaxant activity belong to a group of compounds of medium polarity.Also,our evidence showed that effect induced by dichloromethane and ethyl acetate extracts from A.graveolens is mediated probably by calcium antagonism.Conclusions:A.graveolens represents an ideal source for obtaining lead compounds for designing new therapeutic agents with potential vasorelaxant and antihypertensive effects.

The vasorelaxant effect of pinocembrin on the rat basilar artery and its potential mechanisms

Aim To evaluate the vasorelaxant effects of the flavonone pinocembrin in isolated rat basilar artery rings and to investigate its possible mechanisms. Methods The isotonic contractions of the basilar artery rings from SD rats were recorded. Results Pinocembrin exerted vasorelaxation in a close-dependent manner in KCL （60 mmol · L^-1 ） or 5-HT （ 1 μmol · L^- 1）-induced sustained contraction and partial loss of the vasorelaxation in endothelium- denuded rings. Pretreatment with pinocembrin （30 or 50 μmol · L^-1 ） attenuated contractile responses to KC1 （ 10 - 60 mmol · L^-1 ） and 5-HT （0. 001 - 10 μmol · L^-1 ）. The pinocembrin -induced vasorelaxation was significant- ly reduced by the nitric oxide synthase inhibitor Nco-nitro-L-arginine methyl ester （L-NAME, 100 μmol · L^-1） , the guanylate cyclase inhibitor ODQ （5 μmol · L^-1） and the cyclooxygenase inhibitor indomethacin （5 μmol · L^-l）. The voltage-dependent K＋ channel blocker 4-aminopyridine （100 μmol · L^-1）, the ATP-sensitive K ＋ channel blocker glibenclamide （10μmol · L^-1） and Ca2＋-activated K ＋ channel blocker tetraethylammonium （1 retool· L^-1） remarkably attenuated pinocembrin-induced relaxations. Pinocembrin also inhibited contraction in- duced by increasing external calcium in Ca2＋-free medium plus 60 mmol · L^-1 KC1. Conclusion These results demonstrate that pinocembrin has a vasorelaxant effect on isolated rat basilar artery rings and may exert its action through an endothelium-dependent pathway, involving NO-cGMP, and also through an endothelium-independent 2＋ pathway, opening K ＋ channels and blockade of Ca channels.

Acute Oral Toxicity and Vasorelaxant Effects of Hydroethanolic Extract from Lannea microcarpa Engl. & K. Krause (Anacardiaceae) Trunk Barks in Mice Aortas: Possible Involvement of Intracellular Ca 2+ Mobilization

Lannea microcrapa Engl. & K. Krause (Anacardiaceae) is a fruit and medicinal plant widely used in Burkina Faso. This plant is traditionally used in the treatment of hypertension. The aim of the present study was to evaluate the vasorelaxant effects of the hydroethanolic extract from Lannea microcarpa trunk barks (HE_ELM) on the aorta isolated from NMRI mice. Phytochemical screening by HPTLC, assay of phenolic and flavonoid compounds, assessment of antioxidant activity (DPPH, ABTS, FRAP, and LPO), and myography of HE_ELM (1 - 2000 μg/mL) on mice thoracic aortas in the presence and absence of endothelium were carried out. Endothelium-dependent and endothelium-independant vasodilation were assessed by cumulative addition of Ach (1 nM - 10 μM) on aortic rings precontracted with the thromboxane analogue A2 agonist, 9,11-dideoxy9α,11α-methanoepoxy PGF2α (U46619). L-NAME was used to verify the involvement of NO production in the relaxation mechanism of the extract. Acute oral toxicity of HE_ELM was also evaluated. A phytochemical study revealed the presence of tannins, flavonoids, sterols and triterpenes, saponosides, and high levels of total phenolics and flavonoids. These compounds are thought to be responsible for the extract’s antioxidant and vasorelaxant properties. HE_ELM demonstrated significant antioxidant potential and induced aortic relaxation. Indeed, pharmacological parameters gave EC50 values ranging from 596.45 ± 95.82 μg/mL to 749.48 ± 133.40 μg/mL and Emax values from 85.51% ± 9.59% to 96.81% ± 8.60% for the three conditions of vasodilation of the extract (p > 0.05). A complete antagonism of the contractile effect of U46619 was noted with 1 mg/mL HE_ELM. These results suggest that HE_ELM induces aortic relaxation through a concentration-dependent, endothelium-independent mechanism, possibly involving intracellular calcium mobilization of vascular cells. Acute oral toxicity tests of HE_ELM (2000 mg/kg) showed no mortality or adverse effects, suggesting the extract’s safety and potential as a therapeutic agent for hypertension. This discovery scientifically validates the use of the plant in alternative medicine to treat hypertension.

产前超声用于胎儿动脉导管提前收缩研究进展

胎儿动脉导管(DA)提前收缩可致管腔狭窄、闭锁,进而出现右心室流出道梗阻,引发右心衰竭甚至死亡;常由母体孕期应用前列腺素合成酶抑制剂类药物或摄入富含多酚类物质所致。产前超声可实时、动态观察胎儿DA开放及收缩状态,以彩色多普勒监测血流,进而评估心功能变化。本文围绕产前超声用于胎儿DA提前收缩研究进展进行综述。

红景天注射液降低食管癌根治术患者单肺通气期间肺内分流及血清炎症介质:46例随机对照试验

目的探究红景天对食管癌根治术患者单肺通气期间肺内分流及血炎症介质的影响。方法选择行择期食管癌根治术患者46例,采取随机数字表法分为生理盐水对照组和红景天组(n=23)。红景天组于患者入室后将10mL红景天加入250mL生理盐水或5%葡萄糖注射液缓慢静脉滴注,对照组静滴同等剂量的生理盐水。抽取单肺通气(OLV)开始前(T_(0))、30min(T_(1))、60min(T_(2))、恢复双肺通气后30min(T3)的桡动脉和深静脉血各2mL,行血气分析,根据公式计算出肺内分流率(Qs/Qt)。分别记录各时间点PaO_(2)。于T_(0)、T_(1)、T3时抽取深静脉血2mL,检测血清中α-肿瘤坏死因子(TNF-α)、介素6(IL-6)含量,记录术后肺不张情况。结果与对照组相比,红景天组在T_(1)、T_(2)时,PaO_(2)、Qs/Qt优于对照组(P<0.05),红景天组在T3时IL-6、TNF-α含量降低(P<0.05)。两组患者术后肺不张发生率差异无统计学意义(P>0.05)。结论红景天可减少食管癌根治术患者单肺通气期间肺内分流,改善氧合,降低患者血清中IL-6、TNF-α含量,减轻患者术中肺损伤。

可逆性血管收缩综合征二例

可逆性脑血管收缩综合征(RCVS)是脑动脉节段性和多灶性血管收缩引起的一种可逆性临床综合征,发病早期常难以识别。作者总结了2例不同诱因引起的RCVS患者的病历资料,并对RCVS的临床表现及影像学演变进行了探讨,以期为临床医师早期识别和诊治提供参考。

Hypoxia in the pulmonary vein increases pulmonary vascular resistance independently of oxygen in the pulmonary artery

Introduction:Hypoxic pulmonary vasoconstriction(HPV)can be a challenging clinical problem.It is not fully elucidated where in the circulation the regulation of resistance takes place.It is often referred to as if it is in the arteries,but we hypothesized that it is in the venous side of the pulmonary circulation.Methods:In an open thorax model,pigs were treated with a veno-venous extra corporeal membrane oxygenator to either oxygenate or deoxygenate blood passing through the pulmonary vessels.At the same time the lungs were ventilated with extreme variations of inspired air from 5%to 100%oxygen,making it possible to make combinations of high and low oxygen content through the pulmonary circulation.A flow probe was inserted around the main pulmonary artery and catheters in the pulmonary artery and in the left atrium were used for pressure monitoring and blood tests.Under different combinations of oxygenation,pulmonary vascular resistance(PVR)was calculated.Results:With unchanged level of oxygen in the pulmonary artery and reduced inspired oxygen fraction lowering oxygen tension from 29 to 6.7 kPa in the pulmonary vein,PVR was doubled.With more extreme hypoxia PVR suddenly decreased.Combinations with low oxygenation in the pulmonary artery did not systematic influence PVR if there was enough oxygen in the inspired air and in the pulmonary veins.Discussion:The impact of hypoxia occurs from the alveolar level and forward with the blood flow.The experiments indicated that the regulation of PVR is mediated from the venous side.

Reduction of photodynamic damage of blood vessels in the protected region by(–)-epigallocatechin gallate

Photodynamic therapy(PDT)has been increasingly used in the clinical treatment of neoplastic,inflammatory and infectious skin diseases.However,the generation of reactive oxygen species(ROS)may induce undesired side effects in normal tissue surrounding the treatment lesion,which is a big challenge for the clinical application of PDT.To date,(–)-Epigallocatechin gallate(EGCG)has been widely proposed as an antiangiogenic and antitumor agent for the protection of normal tissue from ROS-mediated oxidative damage.This study evaluates the regulation ability of EGCG for photodynamic damage of blood vessels during hematoporphyrin monomethyl ether(Hemoporfin)-mediated PDT.The quenching rate constants of EGCG for the triplet-state Hemoporfin and photosensitized 1O2 generation are determined to be 6.8×10^(8)M^(−1)S^(−1),respectively.The vasoconstriction of blood vessels in the protected region treated with EGCG hydrogel after PDT is lower than that of the control region treated with pure hydrogel,suggesting an efficiently reduced photodamage of Hemoporfin for blood vessels treated with EGCG.This study indicates that EGCG is an efficient quencher for triplet-state Hemoporfin and 1O2,and EGCG could be potentially used to reduce the undesired photodamage of normal tissue in clinical PDT.

SO_2——一种神秘的生物小分子:SO_2及其衍生物对血管张力的双相-双向性调节作用

为了探索二氧化硫(SO2)作为调节血管张力的细胞气体信号分子的可能性,采用SO2衍生物(亚硫酸钠和亚硫酸氢钠混合物,在中性液体中二者的摩尔比约为3:1)温育大鼠离体胸主动脉血管环的方法,观察SO2及其衍生物对血管环张力的影响.结果发现,SO2及其衍生物在低浓度(<1.35mmol·L-1)下可引起大鼠离体胸主动脉血管环收缩而不引起舒张;在高浓度(>1.35mmol·L-1)下先引起血管环收缩、后引起舒张;且这些变化均与血管内皮无关.这表明不同作用浓度相和不同作用时相,该化学物对血管张力的作用完全相反.由此得出结论:1)低浓度SO2及其衍生物是血管收缩因子;2)高浓度SO2及其衍生物对血管张力的影响是双相-双向性的.内源性的SO2及其衍生物的前体SO/SO2在体内的生理浓度比本研究的低浓度还要低1～2个数量级,其对血管张力的生理作用及其他的生物学作用尚需进一步研究.

MS23对大鼠的不同器官血管环收缩的影响

目的研究MS23对不同激动剂所致不同部位血管收缩的对抗作用或舒张作用。方法大鼠主动脉环和小动脉环的张力舒缩状态分别采用PowerLab和DMT系统记录。结果MS23浓度依赖性抑制去甲肾上腺(NA)引起的主动脉环收缩,使NA浓度-效应曲线非平行性右移,并抑制最大反应,使最大效应下降74.7%。MS23和氨茶碱对高钾和NA引起的大鼠主动脉环预收缩均表现出浓度依赖性舒张效应。去内皮和一氧化氮合酶抑制剂L-NAME对MS23的血管舒张作用无明显影响。小动脉环实验结果为,MS23和氨茶碱浓度依赖性舒张高钾所致大鼠冠状动脉、大脑中动脉、肾动脉和肠系膜动脉环的收缩,此4脏器的小动脉对此二药舒张作用的敏感程度差异均无显著性。结论MS23对多种刺激引起的血管环收缩具有对抗或舒张作用,对血管来源和刺激剂无明显的选择性。其血管舒张作用与NO产生及血管内皮是否存在无关。

黄芪甲甙对大鼠离体肠系膜动脉血管舒缩功能的影响

目的:观察黄芪甲甙对大鼠离体肠系膜动脉舒缩功能的影响,并探讨其可能机制。方法:分离肠系膜动脉1～2级分支制备离体肠系膜血管环固定于微血管张力测定仪,观察黄芪甲甙对血管环舒缩功能的影响。结果:①不同浓度的黄芪甲甙(30mg/L和100mg/L)孵育后,苯肾上腺素引起的血管收缩较对照组明显下降(P<0.05或P<0.01)。②累积浓度的黄芪甲甙对苯肾上腺素(2×10-6mol/L)预收缩的内皮完整或去内皮肠系膜动脉血管环均产生浓度依赖性的舒张作用,中高浓度的黄芪甲甙(10mg/L、30mg/L和100mg/L)对内皮完整组的舒张作用明显强于去内皮组(P<0.05或P<0.01)。③累积浓度的黄芪甲甙对KCl预收缩的肠系膜动脉血管环张力无明显影响(P>0.05)。④L-NAME(10-4mol/L)预处理能显著减弱黄芪甲甙的舒血管作用(P<0.05或P<0.01)。结论:黄芪甲甙具有一定的内皮依赖性舒张血管作用,且主要通过NO途径发挥作用。

黄芪的内皮依赖性血管舒缩作用及其机制

目的 黄芪有一定的治疗高血压作用 ,本研究观察其对大鼠离体胸主动脉环舒缩的影响 ,并探讨其可能机制。方法 采用大鼠离体主动脉环灌流模型 ,观察累积浓度黄芪 (0 .0 1～ 10 0g·L- 1)对基础状态、KCl预收缩和去氧肾上腺素 (PE)预收缩的血管环的作用。结果 黄芪 (0 .0 1～ 10 0g·L- 1)对基础状态或KCl预收缩的内皮完整血管环张力无影响。对PE预收缩的内皮完整血管环 ,黄芪在低浓度 (0 .0 1～ 3.0g·L- 1)时呈浓度依赖性舒张作用 ,此作用可被一氧化氮合酶抑制剂左旋硝基精氨酸甲酯(0 .1mmol·L- 1)或鸟苷酸环化酶抑制剂亚甲蓝 (10μmol·L- 1)预处理所抑制 ;而在高浓度 (10～ 10 0g·L- 1)时呈短暂的收缩作用 ,可被内皮素转换酶抑制剂磷阿米酮 (5 μmol·L- 1)预处理所抑制。黄芪对PE预收缩的去除内皮血管环仅呈微弱的浓度依赖性舒张作用。结论 黄芪对主动脉具有内皮依赖性舒缩双相作用。其舒张机制可能为激活血管内皮细胞一氧化氮 鸟苷酸环化酶途径 ;而其收缩机制可能为促进血管内皮合成内皮素。

CaSR在大鼠血管收缩/舒张反应性调节中的作用

目的研究钙敏感性受体(Ca SR)激动剂对大鼠肠系膜动脉收缩和舒张反应性的影响、以及内皮在其中的作用。方法采用内皮完整和内皮去除的大鼠肠系膜动脉,观察Ca SR特异性激动剂cinacalcet对血管基础张力和预收缩的血管张力的影响、以及不同剂量cinacalcet预处理对去甲肾上腺素(NE)诱导的血管收缩反应性和乙酰胆碱诱导的舒张反应性的影响。结果Ca SR激动剂cinacalcet对静息状态下内皮完整和内皮去除的血管基础张力均无明显影响。在内皮完整的血管环,cinacalcet对预收缩血管有明显的舒张作用,并呈剂量依赖性;内皮去除取消了cinacalcet的舒张作用。Cinacalcet预处理30 min,使内皮完整的血管的收缩反应性明显降低,而对舒张反应性无明显影响。对去除内皮的血管环,cinacalcet预处理对血管收缩/舒张反应性均无明显影响。结论 Ca SR在血管收缩反应性调节中有重要作用,并有明显的内皮依赖性。

黄芪甲苷对正常大鼠离体血管功能的影响

目的观察黄芪甲苷对血管功能的影响并探讨其作用机制。方法采用大鼠离体主动脉环灌流模型,观察黄芪甲苷对血管环收缩和舒张功能的影响。结果黄芪甲苷能够浓度依赖性舒张血管。一氧化氮合酶抑制剂、鸟苷酸环化酶及环加氧酶抑制剂可抑制黄芪甲苷诱导的血管舒张作用。黄芪甲苷能够抑制苯肾上腺、KC l和CaC l2引起的血管收缩。结论黄芪甲苷具有内皮依赖性的舒张血管作用,此作用主要通过NO-cGMP途径发挥作用。黄芪甲苷抑制血管收缩主要通过拮抗外钙内流实现。

厚朴叶中具血管舒张作用的化学成分研究

实验采用离体血管环灌流模型,观察厚朴叶正丁醇萃取部位对去甲肾上腺素预收缩的内皮完整和去除内皮的家兔离体血管环张力的影响。结果显示:厚朴叶正丁醇萃取部位对内皮完整和去除内皮的血管环在一定剂量内呈现浓度依赖性舒张作用,该作用可能与该部位大量成分———槲皮苷和芦丁有关。从该部位分离得到7个化合物,分别为槲皮苷(1),芦丁(2),紫丁香苷(3),丁香脂素-4,4'-双-O-β-D-葡萄糖苷(4),芥子醛-4-O-β-D-吡喃葡萄糖苷(5),松脂素-4-O-β-D-吡喃葡萄糖苷(6),丁香脂素-4-O-β-D-吡喃葡萄糖苷(7)。其中化合物4和6首次从该种植物中分离得到。