Pub Date : 2000-01-01DOI: 10.3109/10623320009072214
M. Nishida, S. Futami, I. Morita, Kazuhiko Maekawa, Sci-itsu Murota
We studied the change in gap junctional intercellular communication (GJIC) on human umbilical vein endothelial cells (HUVEC) under hypoxia-reoxygenation (H-R) conditions by the fluorescence redistribution after photobleaching (FRAP) method. Confluent HUVEC monolayers were exposed to hypoxia (pO2<0.1%) for 12 hours, and then were returned to normal atmospheric conditions for reoxygenation. Contrast microscopic observation showed no significant changes in the morphology of the HUVEC at any times after H-R. Reoxygenation following hypoxia caused time-dependent decrease in GJIC, that is, GJIC reduction was induced after 2 hours and reached maximum at 4-6 hours which recovered to normal levels after 18 hours. Oxidant sensitive fluorescence dye assay revealed that the generation of intracellular free radicals increased during the first 2 hours after reoxygenation. Hydroxyl radical scavengers (MCI-186, DMSO) and an iron chelator (deferoxamine) abolished the reduction of GJIC due to H-R. However, SOD, catalase and probucol were essentially inactive on this reduction. These data suggest that ischemia-reperfusion injury may be caused by a functional defect of GJIC induced by reactive oxygen radicals.
{"title":"Hypoxia-reoxygenation inhibits gap junctional communication in cultured human umbilical vein endothelial cells.","authors":"M. Nishida, S. Futami, I. Morita, Kazuhiko Maekawa, Sci-itsu Murota","doi":"10.3109/10623320009072214","DOIUrl":"https://doi.org/10.3109/10623320009072214","url":null,"abstract":"We studied the change in gap junctional intercellular communication (GJIC) on human umbilical vein endothelial cells (HUVEC) under hypoxia-reoxygenation (H-R) conditions by the fluorescence redistribution after photobleaching (FRAP) method. Confluent HUVEC monolayers were exposed to hypoxia (pO2<0.1%) for 12 hours, and then were returned to normal atmospheric conditions for reoxygenation. Contrast microscopic observation showed no significant changes in the morphology of the HUVEC at any times after H-R. Reoxygenation following hypoxia caused time-dependent decrease in GJIC, that is, GJIC reduction was induced after 2 hours and reached maximum at 4-6 hours which recovered to normal levels after 18 hours. Oxidant sensitive fluorescence dye assay revealed that the generation of intracellular free radicals increased during the first 2 hours after reoxygenation. Hydroxyl radical scavengers (MCI-186, DMSO) and an iron chelator (deferoxamine) abolished the reduction of GJIC due to H-R. However, SOD, catalase and probucol were essentially inactive on this reduction. These data suggest that ischemia-reperfusion injury may be caused by a functional defect of GJIC induced by reactive oxygen radicals.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"95 1","pages":"279-86"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76365522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-01DOI: 10.3109/10623320009165318
I. Blasig, R. Haseloff
{"title":"Second Symposium: Signal Transduction in the Blood-Brain Barrier: Congress Centre IBC Bogensee, Bogensee near Berlin, Germany","authors":"I. Blasig, R. Haseloff","doi":"10.3109/10623320009165318","DOIUrl":"https://doi.org/10.3109/10623320009165318","url":null,"abstract":"","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"110 1","pages":"201-222"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81401212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-01DOI: 10.3109/10623320009072215
Carolyn E. Patterson, Hazel Lum, K. Schaphorst, A. Verin, J. G. Garcia
Elevation of cAMP promotes the endothelial cell (EC) barrier and protects the lung from edema development. Thus, we tested the hypothesis that both increases and decreases in PKA modulate EC function and coordinate distribution of regulatory, adherence, and cytoskeletal proteins. Inhibition of PKA activity by RpcAMPS and activation by cholera toxin was verified by assay of kemptide phosphorylation in digitonin permeabilized EC. Inhibition of PKA by RpcAMPS or overexpression of the endogenous inhibitor, PKI, decreased monolayer electrical impedance and exacerbated the decreases produced by agonists (thrombin and PMA). RpcAMPS directly increased F-actin content and organization into stress fibers, increased co-staining of actin with both phosphatase 2B and myosin light chain kinase (MLCK), caused reorganization of focal adhesions, and decreased catenin at cell borders. These findings are similar to those evoked by thrombin. In contrast, cholera toxin prevented the agonist-induced resistance decrease and protein redistribution. Although PKA activation attenuated thrombin-induced myosin light chain (MLC) phosphorylation, PKA inhibition per se did not cause MLC phosphorylation or affect [Ca2+]i. These studies indicate that a decrease in PKA activity alone can produce disruption of barrier function via mechanisms not involving MLCK and support a central role for cAMP/PKA in regulation of cytoskeletal and adhesive protein function in EC which correlates with altered barrier function.
{"title":"Regulation of endothelial barrier function by the cAMP-dependent protein kinase.","authors":"Carolyn E. Patterson, Hazel Lum, K. Schaphorst, A. Verin, J. G. Garcia","doi":"10.3109/10623320009072215","DOIUrl":"https://doi.org/10.3109/10623320009072215","url":null,"abstract":"Elevation of cAMP promotes the endothelial cell (EC) barrier and protects the lung from edema development. Thus, we tested the hypothesis that both increases and decreases in PKA modulate EC function and coordinate distribution of regulatory, adherence, and cytoskeletal proteins. Inhibition of PKA activity by RpcAMPS and activation by cholera toxin was verified by assay of kemptide phosphorylation in digitonin permeabilized EC. Inhibition of PKA by RpcAMPS or overexpression of the endogenous inhibitor, PKI, decreased monolayer electrical impedance and exacerbated the decreases produced by agonists (thrombin and PMA). RpcAMPS directly increased F-actin content and organization into stress fibers, increased co-staining of actin with both phosphatase 2B and myosin light chain kinase (MLCK), caused reorganization of focal adhesions, and decreased catenin at cell borders. These findings are similar to those evoked by thrombin. In contrast, cholera toxin prevented the agonist-induced resistance decrease and protein redistribution. Although PKA activation attenuated thrombin-induced myosin light chain (MLC) phosphorylation, PKA inhibition per se did not cause MLC phosphorylation or affect [Ca2+]i. These studies indicate that a decrease in PKA activity alone can produce disruption of barrier function via mechanisms not involving MLCK and support a central role for cAMP/PKA in regulation of cytoskeletal and adhesive protein function in EC which correlates with altered barrier function.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"45 1","pages":"287-308"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76929435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-01DOI: 10.3109/10623320009072211
B. Jeon, S. Chang, J. W. Kim, Y. Hong, S. Yoon, I. Choe
The effect of high blood flow on the expression of endothelial nitric oxide synthase has been investigated in the femoral arteriovenous shunt (AVS) rats created by inserting U-shaped polyurethane tubes in the left femoral arteries and veins. Three days after inserting the femoral AVS, the mean aortic blood flow rate in the abdominal aorta of the AVS rats was about 2.0 times higher than that in the control rats (110.0 +/- 8.4 ml/min vs 52.7 +/- 2.7 ml/min, p < 0.001). The competitive reverse transcriptase-polymerase chain reaction (RT-PCR) data revealed that the mRNA expression level of the endothelial constitutive nitric oxide synthase (ecNOS) was increased in the aortas of the femoral AVS rats compared to that in the control rats. Western blot analysis using a monoclonal antibody against ecNOS revealed that the ecNOS protein levels were markedly increased in the aortas of femoral AVS rats, but ecNOS protein levels in aortas without endothelium were not significantly increased. Inducible nitric oxide synthase (iNOS) protein was not expressed in the aortic tissues with and without endothelium in the control rats. This iNOS expression was not increased by the high blood flow in the femoral AVS rats. These findings suggest that high blood flow could up-regulate the expression levels of ecNOS mRNA and proteins in femoral arteriovenous shunt rats.
采用u型聚氨酯管置入左股动静脉分流(AVS)大鼠，研究了高血流量对血管内皮型一氧化氮合酶表达的影响。AVS组大鼠腹主动脉平均血流量(110.0 +/- 8.4 ml/min vs 52.7 +/- 2.7 ml/min, p < 0.001)约为对照组的2.0倍。竞争性逆转录聚合酶链反应(RT-PCR)结果显示，与对照组相比，AVS大鼠主动脉内皮型一氧化氮合酶(ecNOS) mRNA表达水平升高。利用抗ecNOS单克隆抗体进行Western blot分析，发现AVS大鼠股动脉中ecNOS蛋白水平明显升高，而无内皮主动脉中ecNOS蛋白水平无明显升高。诱导型一氧化氮合酶(iNOS)蛋白在无内皮大鼠主动脉组织中均无表达。在股动脉AVS大鼠中，iNOS的表达不因高血流量而增加。以上结果提示，高血流量可上调股动静脉分流大鼠ecNOS mRNA和蛋白的表达水平。
{"title":"Effect of high blood flow on the expression of endothelial constitutive nitric oxide synthase in rats with femoral arteriovenous shunts.","authors":"B. Jeon, S. Chang, J. W. Kim, Y. Hong, S. Yoon, I. Choe","doi":"10.3109/10623320009072211","DOIUrl":"https://doi.org/10.3109/10623320009072211","url":null,"abstract":"The effect of high blood flow on the expression of endothelial nitric oxide synthase has been investigated in the femoral arteriovenous shunt (AVS) rats created by inserting U-shaped polyurethane tubes in the left femoral arteries and veins. Three days after inserting the femoral AVS, the mean aortic blood flow rate in the abdominal aorta of the AVS rats was about 2.0 times higher than that in the control rats (110.0 +/- 8.4 ml/min vs 52.7 +/- 2.7 ml/min, p < 0.001). The competitive reverse transcriptase-polymerase chain reaction (RT-PCR) data revealed that the mRNA expression level of the endothelial constitutive nitric oxide synthase (ecNOS) was increased in the aortas of the femoral AVS rats compared to that in the control rats. Western blot analysis using a monoclonal antibody against ecNOS revealed that the ecNOS protein levels were markedly increased in the aortas of femoral AVS rats, but ecNOS protein levels in aortas without endothelium were not significantly increased. Inducible nitric oxide synthase (iNOS) protein was not expressed in the aortic tissues with and without endothelium in the control rats. This iNOS expression was not increased by the high blood flow in the femoral AVS rats. These findings suggest that high blood flow could up-regulate the expression levels of ecNOS mRNA and proteins in femoral arteriovenous shunt rats.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"61 1","pages":"243-52"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90590367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-01-01DOI: 10.3109/10623329709052600
W. Sluiter, R. W. D. Waal, M. D. Ruiter
{"title":"Highlights of the 9th Endothelium Symposium, Rotterdam, the Netherlands","authors":"W. Sluiter, R. W. D. Waal, M. D. Ruiter","doi":"10.3109/10623329709052600","DOIUrl":"https://doi.org/10.3109/10623329709052600","url":null,"abstract":"","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"40 1","pages":"369-371"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78441230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-01DOI: 10.3109/10623329609024697
V. Patel, Jamie W. Meyer, David K. Johnson, R. Abdul-karim, L. M. Ziegler, L. Kauffman, K. Schillinger, L. Lemanski, J. Holland
In order to study the signal transduction mechanism of endothelial perturbation, the effects of phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu), both protein kinase C (PKC) activators, on cultured human endothelial cell (EC) hydrogen peroxide (H2O2) generation, endocytotic activity, and cytoskeletal structure have been investigated. EC were incubated with 1-100 nM PMA, or PDBu, and cellular H2O2 generation and endocytotic activity measured. PMA and PDBu exposure caused dose-dependent rises in EC H2O2 production. Likewise, EC incubated with PMA and PDBu had dose-related endocytosis increases. Cytoskeletal inspection of 10 nM PMA-perturbed EC revealed structural remodeling with stress fiber formation. Similar cellular functional changes occur in EC exposed to high low-density lipoprotein (LDL) concentrations. Protein kinase C (PKC) inhibition with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) prevented cytoskeletal remodeling in PMA-stimulated EC. In differenc...
{"title":"Protein Kinase C Inhibitors Prevent Cultured Human Endothelial Cell Stress Fiber Formation, but not Heightened Endocytosis","authors":"V. Patel, Jamie W. Meyer, David K. Johnson, R. Abdul-karim, L. M. Ziegler, L. Kauffman, K. Schillinger, L. Lemanski, J. Holland","doi":"10.3109/10623329609024697","DOIUrl":"https://doi.org/10.3109/10623329609024697","url":null,"abstract":"In order to study the signal transduction mechanism of endothelial perturbation, the effects of phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu), both protein kinase C (PKC) activators, on cultured human endothelial cell (EC) hydrogen peroxide (H2O2) generation, endocytotic activity, and cytoskeletal structure have been investigated. EC were incubated with 1-100 nM PMA, or PDBu, and cellular H2O2 generation and endocytotic activity measured. PMA and PDBu exposure caused dose-dependent rises in EC H2O2 production. Likewise, EC incubated with PMA and PDBu had dose-related endocytosis increases. Cytoskeletal inspection of 10 nM PMA-perturbed EC revealed structural remodeling with stress fiber formation. Similar cellular functional changes occur in EC exposed to high low-density lipoprotein (LDL) concentrations. Protein kinase C (PKC) inhibition with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) prevented cytoskeletal remodeling in PMA-stimulated EC. In differenc...","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"35 1","pages":"207-218"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76156778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-01DOI: 10.3109/10623329609024703
H. Mertens, G. Rubanyi
Although reduced endothelium—dependent coronary vasodilation is a consistent finding in patients with hypertension, studies in perfused hearts isolated from spontaneously hypertensive rats (SHR) lead to controversial results. One possible explanation is that coronary vascular reactivity in SHR hearts were studied at different fixed perfusion pressure levels, which were outside the arterial blood pressure range found in these animals. Therefore, the objective of the present experiments was to systematically study the effect of an endothelium-dependent (serotonin) and endothelium—independent (sodium nitroprusside, SNP) vasodilator on coronary flow rate at a wide range of perfusion pressure levels (55 to 130 mmHg) in saline perfused hearts isolated from normotensive (NWR) and SH rats. The pressure-flow relationship showed coronary flow autoregulation at different pressure levels in the two groups (55 to 90 mmHg in NWR hearts and 110 to 130 mmHg in SHR hearts). At a maximally effective concentration (104M) co...
{"title":"Relationship Between Perfusion Pressure and Coronary Vasoreactivity in Saline Perfused Hearts Isolated from Normotensive and Spontaneously Hypertensive Rats: Role of Endothelium","authors":"H. Mertens, G. Rubanyi","doi":"10.3109/10623329609024703","DOIUrl":"https://doi.org/10.3109/10623329609024703","url":null,"abstract":"Although reduced endothelium—dependent coronary vasodilation is a consistent finding in patients with hypertension, studies in perfused hearts isolated from spontaneously hypertensive rats (SHR) lead to controversial results. One possible explanation is that coronary vascular reactivity in SHR hearts were studied at different fixed perfusion pressure levels, which were outside the arterial blood pressure range found in these animals. Therefore, the objective of the present experiments was to systematically study the effect of an endothelium-dependent (serotonin) and endothelium—independent (sodium nitroprusside, SNP) vasodilator on coronary flow rate at a wide range of perfusion pressure levels (55 to 130 mmHg) in saline perfused hearts isolated from normotensive (NWR) and SH rats. The pressure-flow relationship showed coronary flow autoregulation at different pressure levels in the two groups (55 to 90 mmHg in NWR hearts and 110 to 130 mmHg in SHR hearts). At a maximally effective concentration (104M) co...","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"49 1","pages":"281-288"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77438525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-01DOI: 10.3109/10623329609024690
L. Fuchs
A genetic model of cardiomyopathy, the Syrian cardiomyopathic hamster, is characterized by myocardial necrosis and dysfunction which may be initiated by inadequate coronary blood flow. The mechanisms mediating coronary vasospasm observed during the development of cardiomyopathy in this model are unknown. The present study utilized isolated coronary arteries (150-250 pm diameter) from cardiomyopathic (M) and Golden Syrian control (C) hamsters to determine if endothelial dysfunction was present during the necrotic stage of cardiomyopathy (60-90 days of age). Intraluminal diameter was continuously recorded in coronary arteries maintained at an intraluminal pressure of 40 mxnhg. In pre-constricted vessels, relaxation to the endothelium-dependent vasodilator, acetylcholine (ACh), was impaired in vessels from M compared to C hamsters. Inhibition of nitric oxide synthase activity with N-nitro-L-arginine (LNA) significantly reduced relaxation to ACh in coronary arteries from C hamsters. However, LNA had little ef...
心肌病的遗传模型，叙利亚心肌病仓鼠，其特征是心肌坏死和功能障碍，这可能是由冠状动脉血流量不足引起的。在该模型中，在心肌病发展过程中观察到的介导冠状动脉痉挛的机制尚不清楚。本研究利用心肌病(M)和金叙利亚对照(C)仓鼠的分离冠状动脉(直径150-250 pm)来确定在心肌病坏死阶段(60-90日龄)是否存在内皮功能障碍。连续记录冠状动脉腔内直径，维持腔内压40mxhg。在预收缩血管中，与C仓鼠相比，M仓鼠血管中内皮依赖性血管扩张剂乙酰胆碱(ACh)的松弛受损。用n -硝基- l -精氨酸(LNA)抑制一氧化氮合酶活性可显著降低C仓鼠冠状动脉对乙酰胆碱的松弛。然而，LNA几乎没有……
{"title":"Superoxide Anions Contribute to Impaired Endothelium-Dependent Relaxation in Coronary Arteries of Young Cardiomyopathic Hamsters","authors":"L. Fuchs","doi":"10.3109/10623329609024690","DOIUrl":"https://doi.org/10.3109/10623329609024690","url":null,"abstract":"A genetic model of cardiomyopathy, the Syrian cardiomyopathic hamster, is characterized by myocardial necrosis and dysfunction which may be initiated by inadequate coronary blood flow. The mechanisms mediating coronary vasospasm observed during the development of cardiomyopathy in this model are unknown. The present study utilized isolated coronary arteries (150-250 pm diameter) from cardiomyopathic (M) and Golden Syrian control (C) hamsters to determine if endothelial dysfunction was present during the necrotic stage of cardiomyopathy (60-90 days of age). Intraluminal diameter was continuously recorded in coronary arteries maintained at an intraluminal pressure of 40 mxnhg. In pre-constricted vessels, relaxation to the endothelium-dependent vasodilator, acetylcholine (ACh), was impaired in vessels from M compared to C hamsters. Inhibition of nitric oxide synthase activity with N-nitro-L-arginine (LNA) significantly reduced relaxation to ACh in coronary arteries from C hamsters. However, LNA had little ef...","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"4 1","pages":"141-149"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91362907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-01DOI: 10.3109/10623329609024679
Jianben Song, D. Zawieja, H. Granger, A. H. Goodman, M. Davis
In coronary endothelium, bradykinin (BK) modulates production of vasodilators by stimulating Ca2+ influx. To examine the ionic currents involved in this process, we applied BK (100 nM) to single bovine coronary venular endothelial cells (CVEC) while recording membrane potential (Em) or whole-cell current simultaneously with [Ca2+]i. The resting potential (Er) of unstimulated cells was bimodally distributed (-70 ± 9 mV, n = 26; -15 ± 8 mV, n = 30). Irrespective of Er, BK evoked a biphasic [Ca2+]i increase simultaneously with a change in Em. When Er was negative to -30 mV, depolarizations were typically observed. When Er was positive to -30 mV, transient hyperpolarizations were typically observed. Under voltage clamp, [Ca2+], increased as the membrane hyperpolarized and the ratio Δ[Ca2+]i/ΔEm was greater in the presence of BK than in unstimulated cells. Many, but not all, cells exhibited an outward K+ current that appeared to be Ca2+ dependent. When present, this current typically predominated over other cu...
在冠状动脉内皮中，缓激素(BK)通过刺激Ca2+内流调节血管舒张剂的产生。为了研究这一过程中涉及的离子电流，我们将BK (100 nM)应用于单个牛冠状静脉内皮细胞(CVEC)，同时记录膜电位(Em)或全细胞电流与[Ca2+]i。未受刺激细胞的静息电位Er呈双峰分布(-70±9 mV, n = 26;-15±8mv, n = 30)。与Er无关，BK在Em变化的同时引起双相[Ca2+]i增加。当Er为负至-30 mV时，通常观察到去极化。当Er为正至-30 mV时，通常观察到瞬态超极化。在电压箝位下，[Ca2+]随着膜的超极化而增加，BK存在时，[Ca2+]i/ΔEm的比值Δ大于未刺激的细胞。许多，但不是全部，细胞表现出外向的钾离子电流，似乎是Ca2+依赖。当存在时，这种电流通常比其他电流占主导地位。
{"title":"Multiple Ionic Mechanisms Activated by Bradykinin in Coronary Venular Endothelial Cells","authors":"Jianben Song, D. Zawieja, H. Granger, A. H. Goodman, M. Davis","doi":"10.3109/10623329609024679","DOIUrl":"https://doi.org/10.3109/10623329609024679","url":null,"abstract":"In coronary endothelium, bradykinin (BK) modulates production of vasodilators by stimulating Ca2+ influx. To examine the ionic currents involved in this process, we applied BK (100 nM) to single bovine coronary venular endothelial cells (CVEC) while recording membrane potential (Em) or whole-cell current simultaneously with [Ca2+]i. The resting potential (Er) of unstimulated cells was bimodally distributed (-70 ± 9 mV, n = 26; -15 ± 8 mV, n = 30). Irrespective of Er, BK evoked a biphasic [Ca2+]i increase simultaneously with a change in Em. When Er was negative to -30 mV, depolarizations were typically observed. When Er was positive to -30 mV, transient hyperpolarizations were typically observed. Under voltage clamp, [Ca2+], increased as the membrane hyperpolarized and the ratio Δ[Ca2+]i/ΔEm was greater in the presence of BK than in unstimulated cells. Many, but not all, cells exhibited an outward K+ current that appeared to be Ca2+ dependent. When present, this current typically predominated over other cu...","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"4 1","pages":"29-40"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84852679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-01-01DOI: 10.3109/10623329609024689
M. Clarke, K. Pritchard, M. Medow, P. McNeil
We report here that exposure of large vessel EC to clinically relevant, atherogenic levels of native LDL (240 mg cholesterol/dL) increases the incidence and severity of shear-induced EC plasma membrane wound injury in vitro. The proportion of LDL-treated EC that survived mechanical shearing in suspension was significantly less (∼20%; p < 0.005) than that of control, untreated EC. Moreover, the amount of a fluorescent, cytoplasmic wound marker, detected by flow cytometry, in surviving LDL-treated cells was significantly more (∼2 log units; p < 0.005) than that detected in surviving, control EC. Mechanically sheared LDL-treated EC released significantly more (∼2 fold; p < 0.02) bFGF than sheared, control EC. LDL treatment of EC resulted in an increase of ∼60% in membrane-associated cholesterol, and an increase in the cholesterol/phospholipid ratio from 0.6 to 1.3. Fluorescence anisotropy revealed that the plasma membrane fluidity (PMF) of LDL-treated EC was significantly lower than that of control EC. When ...
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