The effect of lanthanum ( Ⅲ ) (La^3 + ) on cytosolic free calcium ( [ Ca^2 + ] i ) in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluo...The effect of lanthanum ( Ⅲ ) (La^3 + ) on cytosolic free calcium ( [ Ca^2 + ] i ) in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluorescent probe by using a confocal laser scanning microscope. La^3+ does not alter basal [Ca^2+ ]i levels and cell spread area at the concentration of 1.00 × 10^- 8 mol· L ^- 1. However, La^3 + at higher concentrations ( 1. 00 × 10^ - 5 and 1.00 × 10^- 7 mol· L^- 1 ) decreases [ Ca^2 + ] i levels and cell spread area, and greater decreases are observed for the higher concentrations of La^3 + . Since [Ca^2 + ]i affects cytoskeleton and the adhesion properties of osteoclasts, our results seem to suggest that La^3 + inhibit bone resorption by decreasing [Ca^2+]i in rabbit mature osteoclasts.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
AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout th...AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.展开更多
To investigate the intracellular mechanism that interleukin 1β (IL 1β) facilitates epileptic seizure and neuronal damage, the effect of IL 1β alone or IL 1β plus glutamate (Glu) on the intracellular free calci...To investigate the intracellular mechanism that interleukin 1β (IL 1β) facilitates epileptic seizure and neuronal damage, the effect of IL 1β alone or IL 1β plus glutamate (Glu) on the intracellular free calcium ([Ca 2+ ] i) of single cultured hippocampal neuron was examined by using EPC 9 light electricity measurement system. The results showed that IL 1β of different concentrations (5×10 3 U/L, 10×10 3 U/L, 20×10 3 U/L, 30×10 3 U/L, 50×10 3 U/L, 100×10 3 U/L) failed to affect the neuronal [Ca 2+ ] i, but IL 1β could facilitate the augmentation of neuronal [Ca 2+ ] i induced by Glu in a dose dependent pattern. MK 801 inhibited the effect of Glu on [Ca 2+ ] i, and also inhibited the effect of IL 1β on [Ca 2+ ] i induced by Glu, while verapamil did not influence the effect of Glu or IL 1β. It is concluded that IL 1β, as a neuromodulator, can facilitate the activation of NMDA receptor by Glu, induce the increase of intracellular calcium, which enhances the excitement of neuron.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
Aim:To study the relaxation mechanisms of tetrandrine(Tet)on the corpus cavernosum smooth muscle.Methods: The corpus cavernosum smooth muscle cells from New Zealand white rabbits were cultured in vitro.[Ca^(2+)]_i was...Aim:To study the relaxation mechanisms of tetrandrine(Tet)on the corpus cavernosum smooth muscle.Methods: The corpus cavernosum smooth muscle cells from New Zealand white rabbits were cultured in vitro.[Ca^(2+)]_i was measured by Fluorescence Ion Digital Imaging System,using Fluo-2/AM as a Ca^(2+)-sensitive fluorescent indicator. Results:Tet(1,10 and 100 μmol/L)had no effect on the resting [Ca^(2+)]_i(P>0.05).In the presence of extracellular Ca^(2+)(2.5 mmol/L),Tet(1,10 and 100 μmol/L)inhibited [Ca^(2+)]_i elevation induced by high K^+ and phenylephrine(PE) in a concentration-dependent manner(P<0.05).In calcium free solution containing egtaic acid,Tet(1 and 10 μmol/L) had no inhibitory effects on [Ca^(2+)]_i elevation induced by PE(P>0.05).However,Tet(100μmol/L)inhibited [Ca^(2+)]_i elevation induced by PE(P<0.05).Conclusion:Tet inhibited the Ca^(2+)influx from the extracellular site via voltage- activated Ca^(2+)channel and α_1-adrenoceptor-operated Ca^(2+)channel.At a high concentration,Tet might inhibit the cytosolic calcium pool release in cultured corpus cavernosum smooth muscle cells.This inhibitory action on [Ca^(2+)]_i might be one of the relaxation mechanisms of Tet on the corpus cavernosum smooth muscle.(Asian J Androl 2006 Jul;8:405-409)展开更多
An ICP-OES method has been developed to estimate Calcium and Phosphorous in In vitro phosphate binding study of Eliphos Tablets. The method is selective and is capable of detecting calcium and phosphorous in the prese...An ICP-OES method has been developed to estimate Calcium and Phosphorous in In vitro phosphate binding study of Eliphos Tablets. The method is selective and is capable of detecting calcium and phosphorous in the presence of other trace elements. The method has been validated using RF power of 1500 watts, plasma flow of 15L/min, Nebuliser flow of 0.8 L/min and plasma view at radial mode for calcium and axial mode for phosphorus. The wavelength was monitored for calcium and phosphorous at 317.933 nm and 213.677 nm respectively. The method has been validated in terms of specificity, precision, linearity, accuracy, limit of quantification and ruggedness. The In vitro binding studies were performed for Eliphos Tablets at eight dif- ferent phosphate concentrations by incubating at 37.0?C and analysis was performed using the validated method to estimate free calcium and phosphorus. The objective of the study is to provide an alternate In vitro method to estimate the binding capacity of calcium acetate tablets to avoid the expensive in-vivo bio clinical studies.展开更多
The changes of the cytoplasmic free calcium level in the neutrophils after smoke in-halation injury were observed in rabbits and then the effects of tetrandrine,a calcium antago-nist,on the changes of free calcium lev...The changes of the cytoplasmic free calcium level in the neutrophils after smoke in-halation injury were observed in rabbits and then the effects of tetrandrine,a calcium antago-nist,on the changes of free calcium level were studied.It was found that the number of neu-trophils increased significantly preceded by a transient decrease in the blood and also increasedin the bronehoalveolar lavage fluid after smoke inhalation.and the level of cytoplasmic free calci-um in the blood neutrophil increased likewise.Administration of tetrandrine resulted in a reduc-tion of the neutrophils number in the lungs and the free calcium level in the blood neutrophils toalleviate the pulmonary injury due to smoke inhalation.It is believed that there is a close rela-tionship between the activation of neutrophils and the pathophysiological changes of the lungs,and tetrandrine can exert its therapeutic effects on the injury by decreasing the free calcium levelin the neutrophils to modulate their functions.展开更多
Calcium homeostasis in synaptosomes is altered during aging. The intrasynaptomal free calcium concentration ([Ca2+]i) was determined in 3- and 24-month-old rats treated with or without Rbl and Rgl. As expected, the [C...Calcium homeostasis in synaptosomes is altered during aging. The intrasynaptomal free calcium concentration ([Ca2+]i) was determined in 3- and 24-month-old rats treated with or without Rbl and Rgl. As expected, the [Ca2-]i level increased with age. Treatment with Rbl and Rgl elicited an obvious decrease of [Ca2+]i content, especially in aged rates. In addition, Rbl and Rgl significantly stimulated the activity of Na+, K+-ATPase while Rbl inhibited the activity of Ca2+, Mg2--ATPase arid calmodulin. In view of the close relationship of [Ca2-]i level with aging, the changes of [Ca2+]i induced by Rbl and Rgl, as shown by our results, might provide an explanation of the mechanisms of their antiaging function.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
Summary: The effects of 3, 4-Dihydroxyacetophenone (3, 4-DHAP) on cytosolic free calcium [Ca~2+ ]_i in pulmonary artery endothelia (PAECs) and smooth muscle cells (PASMCs) during acute hypoxia were studied. Porcine pu...Summary: The effects of 3, 4-Dihydroxyacetophenone (3, 4-DHAP) on cytosolic free calcium [Ca~2+ ]_i in pulmonary artery endothelia (PAECs) and smooth muscle cells (PASMCs) during acute hypoxia were studied. Porcine pulmonary artery endothelial and smooth muscle cells (PASMCs) were cultured primarily, and they were divided into 4 groups: groups incubated under normoxia or hypoxia and those with or without treatment with 3, 4-DHAP. The [Ca~2+ ]_i of both PAECs and PASMCs was measured by determining the fluorescence of fura 2 AM on spetrofluorometer. Our results showed that hypoxia caused significant elevation of [Ca~2+ ]_i, in both PAECs and PASMCs, 3, 4-DHAP could attenuate the hypoxic elevation of [Ca~2+ ]_i only in PASMCs but not in PAECs. It is concluded that 3, 4-DHAP decreases the hypoxic elevation of [Ca~2+ ]_i in PASMCs. This might contribute to its inhibitory effect on hypoxic pulmonary vasoconstriction.展开更多
采用传统的固相反应法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_(3)(BCZT)以及掺杂Al-Mg-Ca玻璃粉的BCZT无铅压电陶瓷。首先研究了预烧温度对BCZT陶瓷粉体的影响,其次研究了掺杂Al-Mg-Ca玻璃粉对BCZT无铅压电陶瓷的烧结性能、介...采用传统的固相反应法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_(3)(BCZT)以及掺杂Al-Mg-Ca玻璃粉的BCZT无铅压电陶瓷。首先研究了预烧温度对BCZT陶瓷粉体的影响,其次研究了掺杂Al-Mg-Ca玻璃粉对BCZT无铅压电陶瓷的烧结性能、介电性能和压电性能的影响。最后通过正交试验确定了其烧结工艺。结果显示BCZT粉体的最佳预烧温度在1100℃。掺杂Al-Mg-Ca玻璃粉能够有效降低BCZT陶瓷的烧结温度。通过烧结工艺正交实验获得了最佳烧结工艺:1100℃预烧,1350℃烧结,升温速度为2℃/min,保温时间为7 h,在110 min降温至800℃。验证正交试验所得到的结果是掺杂Al-Mg-Ca玻璃粉的BCZT陶瓷的居里温度点的介电常数为12228,压电常数d_(33)为425 p C/N。展开更多
Effects of ATF on cytosclic free calcium ([Ca2+]i) in single porcine pulmonary artery endothelia cell were studied.Using a dual-wavelength excitation on microflurometry.it was found that ATP evoked a rapid transient i...Effects of ATF on cytosclic free calcium ([Ca2+]i) in single porcine pulmonary artery endothelia cell were studied.Using a dual-wavelength excitation on microflurometry.it was found that ATP evoked a rapid transient in[Ca2+]i which was then followed by a maintained elevation of[Ca2+]i.The removal of extracellular Ca2+ abolished the maintained plateform, but exerted no obvious effect on the initial-transient.These results suggest that ATP stimulates both calcium release from intracellular calcium pool(s)and calcium influx across the Plasma membrane from extracellular space.展开更多
文摘The effect of lanthanum ( Ⅲ ) (La^3 + ) on cytosolic free calcium ( [ Ca^2 + ] i ) in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluorescent probe by using a confocal laser scanning microscope. La^3+ does not alter basal [Ca^2+ ]i levels and cell spread area at the concentration of 1.00 × 10^- 8 mol· L ^- 1. However, La^3 + at higher concentrations ( 1. 00 × 10^ - 5 and 1.00 × 10^- 7 mol· L^- 1 ) decreases [ Ca^2 + ] i levels and cell spread area, and greater decreases are observed for the higher concentrations of La^3 + . Since [Ca^2 + ]i affects cytoskeleton and the adhesion properties of osteoclasts, our results seem to suggest that La^3 + inhibit bone resorption by decreasing [Ca^2+]i in rabbit mature osteoclasts.
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.
基金The Research Committee of Intractable Pancreatic Diseases, provided by the Ministry of Health, Labour, and Welfare, Japan, No. 50253448
文摘AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.
文摘To investigate the intracellular mechanism that interleukin 1β (IL 1β) facilitates epileptic seizure and neuronal damage, the effect of IL 1β alone or IL 1β plus glutamate (Glu) on the intracellular free calcium ([Ca 2+ ] i) of single cultured hippocampal neuron was examined by using EPC 9 light electricity measurement system. The results showed that IL 1β of different concentrations (5×10 3 U/L, 10×10 3 U/L, 20×10 3 U/L, 30×10 3 U/L, 50×10 3 U/L, 100×10 3 U/L) failed to affect the neuronal [Ca 2+ ] i, but IL 1β could facilitate the augmentation of neuronal [Ca 2+ ] i induced by Glu in a dose dependent pattern. MK 801 inhibited the effect of Glu on [Ca 2+ ] i, and also inhibited the effect of IL 1β on [Ca 2+ ] i induced by Glu, while verapamil did not influence the effect of Glu or IL 1β. It is concluded that IL 1β, as a neuromodulator, can facilitate the activation of NMDA receptor by Glu, induce the increase of intracellular calcium, which enhances the excitement of neuron.
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Aim:To study the relaxation mechanisms of tetrandrine(Tet)on the corpus cavernosum smooth muscle.Methods: The corpus cavernosum smooth muscle cells from New Zealand white rabbits were cultured in vitro.[Ca^(2+)]_i was measured by Fluorescence Ion Digital Imaging System,using Fluo-2/AM as a Ca^(2+)-sensitive fluorescent indicator. Results:Tet(1,10 and 100 μmol/L)had no effect on the resting [Ca^(2+)]_i(P>0.05).In the presence of extracellular Ca^(2+)(2.5 mmol/L),Tet(1,10 and 100 μmol/L)inhibited [Ca^(2+)]_i elevation induced by high K^+ and phenylephrine(PE) in a concentration-dependent manner(P<0.05).In calcium free solution containing egtaic acid,Tet(1 and 10 μmol/L) had no inhibitory effects on [Ca^(2+)]_i elevation induced by PE(P>0.05).However,Tet(100μmol/L)inhibited [Ca^(2+)]_i elevation induced by PE(P<0.05).Conclusion:Tet inhibited the Ca^(2+)influx from the extracellular site via voltage- activated Ca^(2+)channel and α_1-adrenoceptor-operated Ca^(2+)channel.At a high concentration,Tet might inhibit the cytosolic calcium pool release in cultured corpus cavernosum smooth muscle cells.This inhibitory action on [Ca^(2+)]_i might be one of the relaxation mechanisms of Tet on the corpus cavernosum smooth muscle.(Asian J Androl 2006 Jul;8:405-409)
文摘An ICP-OES method has been developed to estimate Calcium and Phosphorous in In vitro phosphate binding study of Eliphos Tablets. The method is selective and is capable of detecting calcium and phosphorous in the presence of other trace elements. The method has been validated using RF power of 1500 watts, plasma flow of 15L/min, Nebuliser flow of 0.8 L/min and plasma view at radial mode for calcium and axial mode for phosphorus. The wavelength was monitored for calcium and phosphorous at 317.933 nm and 213.677 nm respectively. The method has been validated in terms of specificity, precision, linearity, accuracy, limit of quantification and ruggedness. The In vitro binding studies were performed for Eliphos Tablets at eight dif- ferent phosphate concentrations by incubating at 37.0?C and analysis was performed using the validated method to estimate free calcium and phosphorus. The objective of the study is to provide an alternate In vitro method to estimate the binding capacity of calcium acetate tablets to avoid the expensive in-vivo bio clinical studies.
文摘The changes of the cytoplasmic free calcium level in the neutrophils after smoke in-halation injury were observed in rabbits and then the effects of tetrandrine,a calcium antago-nist,on the changes of free calcium level were studied.It was found that the number of neu-trophils increased significantly preceded by a transient decrease in the blood and also increasedin the bronehoalveolar lavage fluid after smoke inhalation.and the level of cytoplasmic free calci-um in the blood neutrophil increased likewise.Administration of tetrandrine resulted in a reduc-tion of the neutrophils number in the lungs and the free calcium level in the blood neutrophils toalleviate the pulmonary injury due to smoke inhalation.It is believed that there is a close rela-tionship between the activation of neutrophils and the pathophysiological changes of the lungs,and tetrandrine can exert its therapeutic effects on the injury by decreasing the free calcium levelin the neutrophils to modulate their functions.
文摘Calcium homeostasis in synaptosomes is altered during aging. The intrasynaptomal free calcium concentration ([Ca2+]i) was determined in 3- and 24-month-old rats treated with or without Rbl and Rgl. As expected, the [Ca2-]i level increased with age. Treatment with Rbl and Rgl elicited an obvious decrease of [Ca2+]i content, especially in aged rates. In addition, Rbl and Rgl significantly stimulated the activity of Na+, K+-ATPase while Rbl inhibited the activity of Ca2+, Mg2--ATPase arid calmodulin. In view of the close relationship of [Ca2-]i level with aging, the changes of [Ca2+]i induced by Rbl and Rgl, as shown by our results, might provide an explanation of the mechanisms of their antiaging function.
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Summary: The effects of 3, 4-Dihydroxyacetophenone (3, 4-DHAP) on cytosolic free calcium [Ca~2+ ]_i in pulmonary artery endothelia (PAECs) and smooth muscle cells (PASMCs) during acute hypoxia were studied. Porcine pulmonary artery endothelial and smooth muscle cells (PASMCs) were cultured primarily, and they were divided into 4 groups: groups incubated under normoxia or hypoxia and those with or without treatment with 3, 4-DHAP. The [Ca~2+ ]_i of both PAECs and PASMCs was measured by determining the fluorescence of fura 2 AM on spetrofluorometer. Our results showed that hypoxia caused significant elevation of [Ca~2+ ]_i, in both PAECs and PASMCs, 3, 4-DHAP could attenuate the hypoxic elevation of [Ca~2+ ]_i only in PASMCs but not in PAECs. It is concluded that 3, 4-DHAP decreases the hypoxic elevation of [Ca~2+ ]_i in PASMCs. This might contribute to its inhibitory effect on hypoxic pulmonary vasoconstriction.
文摘采用传统的固相反应法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1))O_(3)(BCZT)以及掺杂Al-Mg-Ca玻璃粉的BCZT无铅压电陶瓷。首先研究了预烧温度对BCZT陶瓷粉体的影响,其次研究了掺杂Al-Mg-Ca玻璃粉对BCZT无铅压电陶瓷的烧结性能、介电性能和压电性能的影响。最后通过正交试验确定了其烧结工艺。结果显示BCZT粉体的最佳预烧温度在1100℃。掺杂Al-Mg-Ca玻璃粉能够有效降低BCZT陶瓷的烧结温度。通过烧结工艺正交实验获得了最佳烧结工艺:1100℃预烧,1350℃烧结,升温速度为2℃/min,保温时间为7 h,在110 min降温至800℃。验证正交试验所得到的结果是掺杂Al-Mg-Ca玻璃粉的BCZT陶瓷的居里温度点的介电常数为12228,压电常数d_(33)为425 p C/N。
文摘Effects of ATF on cytosclic free calcium ([Ca2+]i) in single porcine pulmonary artery endothelia cell were studied.Using a dual-wavelength excitation on microflurometry.it was found that ATP evoked a rapid transient in[Ca2+]i which was then followed by a maintained elevation of[Ca2+]i.The removal of extracellular Ca2+ abolished the maintained plateform, but exerted no obvious effect on the initial-transient.These results suggest that ATP stimulates both calcium release from intracellular calcium pool(s)and calcium influx across the Plasma membrane from extracellular space.