To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute a...To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2＋ indicator Fura-2/AM was used to observe [Ca^2＋ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid （NFA） and indaryloxyacetic acid （IAA-94） exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2＋ ]i was increased. Under normoxic condition, [Ca^2＋ If was （123.634-18.98） nmol/ L, and in hypoxic condition, [Ca^2＋]i wag （281. 754-16.48） nmol/L （P〈0. 01）. Under normoxic condition, [Ca^2＋ ]i showed no significant change and no effect on Clca channels was observed （P〉 0. 05）. Chronic hypoxia increased [Ca^2＋ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2＋ ]i from （281.75± 16.48） nmot/L to （117.66 ±15.36） nmol/L （P〈0.01）. MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency （A value） from 0. 459±0. 058 to 0. 224±0. 025 （P〈0. 01）. Hypoxia increased [Ca^2＋ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2＋ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.展开更多
To explore the effects of total flavonoids of Hippophae rhamnoides L. （TFH） quercetin （Que） and isorhamnetin （Isor） on the intracellular free calcium （[Ca^2＋]） in vascular smooth muscle cells （VSMC） of spon...To explore the effects of total flavonoids of Hippophae rhamnoides L. （TFH） quercetin （Que） and isorhamnetin （Isor） on the intracellular free calcium （[Ca^2＋]） in vascular smooth muscle cells （VSMC） of spontaneously hypertensive rats （SHR） and Wistar-Kyoto rats （WKY）. Metheds： Fluo 3-acetoxymethylester（Fluo-3/AM） was used to observe the effects of TFH （100mg/L） and its essential monomers, namely Que （10^-4mol/L） and Isor （10^-4mol/L） on changes of [Ca^2＋]1 in cultured SHR and WKY VSMC （abbr. to Ca-SHR ＆ Ca-WKY） following exposure to high K^＋, norepinephrine （NE） and angiotensin Ⅱ （AngⅡ）, and to compare with the effects of verapamil （Ver）. Results： （1） TFH, Que and Isor had inhibitory effects on resting Ca-SHR （P〈0.05）, but had no significant effects on Ca-WKY （P〉0.05）. （2） High K^＋ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）; TFH, Que and Isor could inhibit the elevation of [Ca^2＋]1 induced by high K^＋ -depolarization, with the effects similar to that of Ver, and the effect on Ca-SHR was more significant than that on Ca-WKY （P〈0.05）. （3） NE and Ang Ⅱ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）, TFH, Que and Isor had remarkably inhibitory effect on the elevation of Ca-SHR and Ca-WKY induced by NE or Ang Ⅱ. （4） In the absence of extracellular Ca^2＋ , TFH, Que and Isor also had certain inhibitory effect on Ca-SHR and Ca-WKY induced by NE, and the effect on the former was more significant than that on the latter（P〈0.05）. Ceaclusiea： TFH, Que and Isor might decrease the levels of [Ca^2＋], in VSMCs by blocking both voltage-dependent calcium channels （VDC） and receptoroperated calcium channels （ROC） in physiological or pathological state, which may be one of the important mechanisms of their hypotensive and protective effects on target organs in patients with hypertension.展开更多
Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. lntracellula...Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. lntracellular calcium concentrations were measured by confocal Laser Scanning Microscopy and Fura-3 fluorescence dyeing techniques. Cell growth was measured by MTT assay. Results PDGF-BB increased intracellular calcium concentrations in a dose-dependent manner, and at the same time promote the proliferation of mesangial cells. After preincubation with calcium channel blocker nifedipine or angiotensin converting enzyme inhibitor captopril, both the increase of intracellular calcium concentrations and cell proliferations induced by PDGF-BB were inhibited. Tripteriglum Wilfordii Glycosides （TMG） significantly inhibited the mesangial cell proliferations, but it had no significant effect on intracellular calcium concentrations. Conclusion There was a positive relationship between the elevation of intracellular calcium concentration and cell proliferation in glomerular mesangial cells, but the increase of intracellular calcium concentrations wasn＇t the only way for proliferation.展开更多
By using Fura-2/AM, the effects of magnesium (Mg 2+) on the glutamate-induced increase of intracellular free calcium ([Ca 2+]i) in the cultured hippocampal neurons and the features were investigated by integrated ph...By using Fura-2/AM, the effects of magnesium (Mg 2+) on the glutamate-induced increase of intracellular free calcium ([Ca 2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1×10 —5 mol/L glutamate; Group B receiving 1×10 —5 mol/L glutamate and1×10 —5 mol/L Mg 2+ simultaneously; Group C receiving 1×10 —5 mol/L glutamate again after [Ca 2+]i in group B back to the baseline. The results showed that in group A, [Ca 2+]i was obviously increased. In group B, the changes in [Ca 2+]i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the △[Ca 2+]i was slightly decreased. It was suggested that Mg 2+ could quickly inhibit the rise of [Ca 2+]i induced by glutamate in the cultured hippocampal neurons in rats.展开更多
By using Ca2+ -sensitive fluorescent probe, Fura-2 , the effects of endothelial cell-conditioned medium and hypoxia on intracellular free calcium ( [Ca2+]i) in cultured pulmonary artery smooth muscle cell (PASMC) were...By using Ca2+ -sensitive fluorescent probe, Fura-2 , the effects of endothelial cell-conditioned medium and hypoxia on intracellular free calcium ( [Ca2+]i) in cultured pulmonary artery smooth muscle cell (PASMC) were studied. Normoxic porcine pulmonary artery endothelial cell-conditioned medium (NPAECCM) obviously elevated [Ca2+]i in PASMC,whereas the hypoxic porcine pulmonary artery endothelial cell conditioned medium (HPAECCM)significantly elevated [Ca2+]i in PASMC much more than NPAECCM. Both the effects of NPAECCM and HPAECCM were dependent on the cultured endothelial cell extracellular calcium concentrations, ranged from 1.8 mmol/L to 2. 4 mmol/L.Meanwhile, hypoxia directly increased, which was partially inhibited by verapamil,[Ca2+]i in PASMC through Ca2+ influx pathway.The data suggest that the augmented regulation of endothelial cell on PASMC via Ca2+ second messenger system and the hypoxia-induced Ca2+ influx into PASMC,particularly the former, may be components of mechanisms underlying hypoxic pulmonary vasoconstriction and chronic pulmonary hypertension.展开更多
The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6NBD-ceramide, and then the single cells were examined by laser scanning confocal microscopy (LSCFM) for subce...The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6NBD-ceramide, and then the single cells were examined by laser scanning confocal microscopy (LSCFM) for subcellular distributions of Ca2+ and the location of Golgi apparatus. In these cells, the intracellular Ca2+ were found to be highly concentrated in the Golgi apparatus. The changes of distribution of cytosolic high Ca2+ region and the Golgi apparatus coincided with the cell cycle phase.In calcium free medium, when the plasma membrane of the cells which had been loaded with fluo-3/AM were permeated by digitonin, the fluorescence of the Golgi region decreased far less than that of the cytosol. Our results indicated that the Glogi lumen retained significantly high concentration of free calcium.展开更多
This study measured platelet intracellular free calcium (PFCa 2+ ) of 1003 normal pregnancies in different trimester. The purpose of this study was to find the alteration of PFCa 2+ in normal pregnancy, to pr...This study measured platelet intracellular free calcium (PFCa 2+ ) of 1003 normal pregnancies in different trimester. The purpose of this study was to find the alteration of PFCa 2+ in normal pregnancy, to provide scientific basis for forecasting and preventing PIH (pregnancy induced hypertension). The results showed that the PFCa 2+ concentration was stable and slightly increased with the progression of gestational weeks.展开更多
Aim To investigate the effects of iptakalim, a new structural potassium channel opener （KCO）, on intracellular calcium concentration ([Ca2+]i), protein kinase C （PKC）, and cAMP-dependent kinase （PKA） activities ...Aim To investigate the effects of iptakalim, a new structural potassium channel opener （KCO）, on intracellular calcium concentration ([Ca2+]i), protein kinase C （PKC）, and cAMP-dependent kinase （PKA） activities in rat tail artery smooth muscle cells （RTA-SMC）, and to analyze mechanisms involved in iptakalim reversing hypertensive vascular remodeling. Methods RTA-SMC was cultured and passages 3-4 were used for experiment. [Ca2+]i was measured by laser scanning confocal microscope after loaded with fluorescent indicator fluo-3-acetoxymethylester, and activities of PKA and PKC were detected by commercial assay kits （the nonradioactive PepTag system） following instructions. Results Compared with baseline, [Ca2+]i reduced significantly after iptakalim- or pinacidil-treatment at concentrations of 0.1, 1 and 10 (μmol·L-1), while diazoxide caused significant decrease at concentration of 1 and 10 (μmol·L-1). After preincubation with 1 (μmol·L-1) glibenclamide, [Ca2+]i was not significantly changed when iptakalim, pinacidil or diazoxide were added at concentration of 0.1 and 1 (μmol·L-1). Activities of PKA and PKC increased significantly by 1 μmol·L-1 iptakalim- or pinacidil-treatment, while 1 μmol·L-1 diazoxide induced significant change in activity of PKC but not in that of PKA. Conclusion The characteristics of iptakalim on [Ca2+]i, PKA and PKC are more or less similar to those of pinacidil. Iptakalim decreased [Ca2+]i while increased PKA and PKC activities of RTA-SMCs, which may contribute to its ability to reverse antihypertensive vascular remodeling.展开更多
文摘To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2＋ indicator Fura-2/AM was used to observe [Ca^2＋ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid （NFA） and indaryloxyacetic acid （IAA-94） exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2＋ ]i was increased. Under normoxic condition, [Ca^2＋ If was （123.634-18.98） nmol/ L, and in hypoxic condition, [Ca^2＋]i wag （281. 754-16.48） nmol/L （P〈0. 01）. Under normoxic condition, [Ca^2＋ ]i showed no significant change and no effect on Clca channels was observed （P〉 0. 05）. Chronic hypoxia increased [Ca^2＋ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2＋ ]i from （281.75± 16.48） nmot/L to （117.66 ±15.36） nmol/L （P〈0.01）. MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency （A value） from 0. 459±0. 058 to 0. 224±0. 025 （P〈0. 01）. Hypoxia increased [Ca^2＋ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2＋ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.
基金Supported by One-hundred-people Plan of Hygiene Systemin Shanghai (No .990122)
文摘To explore the effects of total flavonoids of Hippophae rhamnoides L. （TFH） quercetin （Que） and isorhamnetin （Isor） on the intracellular free calcium （[Ca^2＋]） in vascular smooth muscle cells （VSMC） of spontaneously hypertensive rats （SHR） and Wistar-Kyoto rats （WKY）. Metheds： Fluo 3-acetoxymethylester（Fluo-3/AM） was used to observe the effects of TFH （100mg/L） and its essential monomers, namely Que （10^-4mol/L） and Isor （10^-4mol/L） on changes of [Ca^2＋]1 in cultured SHR and WKY VSMC （abbr. to Ca-SHR ＆ Ca-WKY） following exposure to high K^＋, norepinephrine （NE） and angiotensin Ⅱ （AngⅡ）, and to compare with the effects of verapamil （Ver）. Results： （1） TFH, Que and Isor had inhibitory effects on resting Ca-SHR （P〈0.05）, but had no significant effects on Ca-WKY （P〉0.05）. （2） High K^＋ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）; TFH, Que and Isor could inhibit the elevation of [Ca^2＋]1 induced by high K^＋ -depolarization, with the effects similar to that of Ver, and the effect on Ca-SHR was more significant than that on Ca-WKY （P〈0.05）. （3） NE and Ang Ⅱ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）, TFH, Que and Isor had remarkably inhibitory effect on the elevation of Ca-SHR and Ca-WKY induced by NE or Ang Ⅱ. （4） In the absence of extracellular Ca^2＋ , TFH, Que and Isor also had certain inhibitory effect on Ca-SHR and Ca-WKY induced by NE, and the effect on the former was more significant than that on the latter（P〈0.05）. Ceaclusiea： TFH, Que and Isor might decrease the levels of [Ca^2＋], in VSMCs by blocking both voltage-dependent calcium channels （VDC） and receptoroperated calcium channels （ROC） in physiological or pathological state, which may be one of the important mechanisms of their hypotensive and protective effects on target organs in patients with hypertension.
文摘Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. lntracellular calcium concentrations were measured by confocal Laser Scanning Microscopy and Fura-3 fluorescence dyeing techniques. Cell growth was measured by MTT assay. Results PDGF-BB increased intracellular calcium concentrations in a dose-dependent manner, and at the same time promote the proliferation of mesangial cells. After preincubation with calcium channel blocker nifedipine or angiotensin converting enzyme inhibitor captopril, both the increase of intracellular calcium concentrations and cell proliferations induced by PDGF-BB were inhibited. Tripteriglum Wilfordii Glycosides （TMG） significantly inhibited the mesangial cell proliferations, but it had no significant effect on intracellular calcium concentrations. Conclusion There was a positive relationship between the elevation of intracellular calcium concentration and cell proliferation in glomerular mesangial cells, but the increase of intracellular calcium concentrations wasn＇t the only way for proliferation.
文摘By using Fura-2/AM, the effects of magnesium (Mg 2+) on the glutamate-induced increase of intracellular free calcium ([Ca 2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1×10 —5 mol/L glutamate; Group B receiving 1×10 —5 mol/L glutamate and1×10 —5 mol/L Mg 2+ simultaneously; Group C receiving 1×10 —5 mol/L glutamate again after [Ca 2+]i in group B back to the baseline. The results showed that in group A, [Ca 2+]i was obviously increased. In group B, the changes in [Ca 2+]i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the △[Ca 2+]i was slightly decreased. It was suggested that Mg 2+ could quickly inhibit the rise of [Ca 2+]i induced by glutamate in the cultured hippocampal neurons in rats.
文摘By using Ca2+ -sensitive fluorescent probe, Fura-2 , the effects of endothelial cell-conditioned medium and hypoxia on intracellular free calcium ( [Ca2+]i) in cultured pulmonary artery smooth muscle cell (PASMC) were studied. Normoxic porcine pulmonary artery endothelial cell-conditioned medium (NPAECCM) obviously elevated [Ca2+]i in PASMC,whereas the hypoxic porcine pulmonary artery endothelial cell conditioned medium (HPAECCM)significantly elevated [Ca2+]i in PASMC much more than NPAECCM. Both the effects of NPAECCM and HPAECCM were dependent on the cultured endothelial cell extracellular calcium concentrations, ranged from 1.8 mmol/L to 2. 4 mmol/L.Meanwhile, hypoxia directly increased, which was partially inhibited by verapamil,[Ca2+]i in PASMC through Ca2+ influx pathway.The data suggest that the augmented regulation of endothelial cell on PASMC via Ca2+ second messenger system and the hypoxia-induced Ca2+ influx into PASMC,particularly the former, may be components of mechanisms underlying hypoxic pulmonary vasoconstriction and chronic pulmonary hypertension.
文摘The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6NBD-ceramide, and then the single cells were examined by laser scanning confocal microscopy (LSCFM) for subcellular distributions of Ca2+ and the location of Golgi apparatus. In these cells, the intracellular Ca2+ were found to be highly concentrated in the Golgi apparatus. The changes of distribution of cytosolic high Ca2+ region and the Golgi apparatus coincided with the cell cycle phase.In calcium free medium, when the plasma membrane of the cells which had been loaded with fluo-3/AM were permeated by digitonin, the fluorescence of the Golgi region decreased far less than that of the cytosol. Our results indicated that the Glogi lumen retained significantly high concentration of free calcium.
文摘This study measured platelet intracellular free calcium (PFCa 2+ ) of 1003 normal pregnancies in different trimester. The purpose of this study was to find the alteration of PFCa 2+ in normal pregnancy, to provide scientific basis for forecasting and preventing PIH (pregnancy induced hypertension). The results showed that the PFCa 2+ concentration was stable and slightly increased with the progression of gestational weeks.
文摘Aim To investigate the effects of iptakalim, a new structural potassium channel opener （KCO）, on intracellular calcium concentration ([Ca2+]i), protein kinase C （PKC）, and cAMP-dependent kinase （PKA） activities in rat tail artery smooth muscle cells （RTA-SMC）, and to analyze mechanisms involved in iptakalim reversing hypertensive vascular remodeling. Methods RTA-SMC was cultured and passages 3-4 were used for experiment. [Ca2+]i was measured by laser scanning confocal microscope after loaded with fluorescent indicator fluo-3-acetoxymethylester, and activities of PKA and PKC were detected by commercial assay kits （the nonradioactive PepTag system） following instructions. Results Compared with baseline, [Ca2+]i reduced significantly after iptakalim- or pinacidil-treatment at concentrations of 0.1, 1 and 10 (μmol·L-1), while diazoxide caused significant decrease at concentration of 1 and 10 (μmol·L-1). After preincubation with 1 (μmol·L-1) glibenclamide, [Ca2+]i was not significantly changed when iptakalim, pinacidil or diazoxide were added at concentration of 0.1 and 1 (μmol·L-1). Activities of PKA and PKC increased significantly by 1 μmol·L-1 iptakalim- or pinacidil-treatment, while 1 μmol·L-1 diazoxide induced significant change in activity of PKC but not in that of PKA. Conclusion The characteristics of iptakalim on [Ca2+]i, PKA and PKC are more or less similar to those of pinacidil. Iptakalim decreased [Ca2+]i while increased PKA and PKC activities of RTA-SMCs, which may contribute to its ability to reverse antihypertensive vascular remodeling.
