N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils

N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though Ca²⁺ signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ([Ca²⁺]ᵢ) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on [Ca²⁺]ᵢ in human neutrophils. We observed that NAC (1 µM ~ 1 mM) and cysteine (10 µM ~ 1 mM) increased [Ca²⁺]ᵢ in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in [Ca²⁺]ᵢ in human neutrophils was observed. In Ca²⁺-free buffer, NAC- and cysteine-induced [Ca²⁺]ᵢ increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in [Ca²⁺]ᵢ in human neutrophils occur through Ca²⁺ influx. NAC- and cysteine-induced [Ca²⁺]ᵢ increase was effectively inhibited by calcium channel inhibitors SKF96365 (10 µM) and ruthenium red (20 µM). In Na⁺-free HEPES, both NAC and cysteine induced a marked increase in [Ca²⁺]ᵢ in human neutrophils, arguing against the possibility that Na⁺-dependent intracellular uptake of NAC and cysteine is necessary for their [Ca²⁺]ᵢ increasing activity. Our results show that NAC and cysteine induce [Ca²⁺]ᵢ increase through Ca²⁺ influx in human neutrophils via SKF96365- and ruthenium red-dependent way.

Identification of Lys49-PLA2 from crude venom of Crotalus atrox as a human neutrophil-calcium modulating protein

We fortuitously observed a human neutrophil intracellular free-calcium concentration ([Ca2+]i) increasing activity in the commercially available phosphodiesterase I (PDE I), which is actually dried crude venom of Crotalus atrox. As this activity was not observed with another commercially available pure PDE I, we tried to find out the causative molecule(s) present in 'crude' PDE, and identified Lys49-phospholipase A2 (Lys49-PLA2 or K49-PLA2), a catalytically inactive protein which belongs to the phospholipase A2 family, by activity-driven three HPLC (reverse phase, size exclusion, reverse phase) steps followed by SDS-PAGE and LC-MS/MS. K49-PLA2 induced Ca2+ infl ux in human neutrophils without any cytotoxic eff ect. Two calcium channel inhibitors, 2-aminoetoxydiphenyl borate (2-APB) (30 microM) and SKF-96365 (20 microM) signifi cantly inhibited K49-PLA2-induced [Ca2+]i increase. These results suggest that K49-PLA2 modulates [Ca2+]i in human neutrophils via 2-APB- and SKF-96365-sensitive calcium channels without causing membrane disruption.

TRPV1 in Salivary Gland Epithelial Cells Is Not Involved in Salivary Secretion via Transcellular Pathway

Transient receptor potential vanilloid subtype 1 (TRPV1) was originally found in sensory neurons. Recently, it has been reported that TRPV1 is expressed in salivary gland epithelial cells (SGEC). However, the physiological role of TRPV1 in salivary secretion remains to be elucidated. We found that TRPV1 is expressed in mouse and human submandibular glands (SMG) and HSG cells, originated from human submandibular gland ducts at both mRNA and protein levels. However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ([Ca2+]i) in these cells, although carbachol consistently increased [Ca2+]i. Exposure of cells to high temperature (>43degrees C) or acidic bath solution (pH5.4) did not increase [Ca2+]i, either. We further examined the role of TRPV1 in salivary secretion using TRPV1 knock-out mice. There was no significant difference in the pilocarpine (PILO)-induced salivary flow rate between wild-type and TRPV1 knock-out mice. Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone. Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

Cloning and expression of rotavirus nonstructural protein 4 and its interference effect on intrancellu-lar calcium homeostasis / 中华微生物学和免疫学杂志

Objective To construct prokaryotic expression systems of genes of intact rotavirus non -structural protein 4 (NSP4) and 86 to 175 amino acid peptide of NSP4 (NSP486-175) and to identify the bio-activities of the recombinant expression products .Methods Colloidal gold assay was used to screen group A rotavirus antibody-positive stools , from which the viral RNA was extracted and transcribed into cDNA .Then NSP4 gene and NSP486-175 gene were amplified by PCR and inserted into pET-28a(+) vector to construct the prokaryotic expression plasmids of pET-28a(+)-NSP4 and pET-28a(+)-NSP486-175 , which were transformed into E.coli BL21( DE3) and inducted by IPTG .The expressed NSP486-175 protein was purified by Ni-NTA af-finity chromatography and examined by Western blot .Fluo-3 AM ester was used to label intracellular free Ca2+( [ Ca2+] i) in Caco-2 cells and laser scanning confocal microscopy was performed to detect the effect of NSP486-175 protein on [Ca2+]i.Results DNA sequencing indicated that NSP4 gene and NSP486-175 gene were consistent with the corresponding sequences in NCBI .The intact NSP4 had difficulty in expressing in E.coli. NSP486-175 protein mainly existed in soluble form with a relative molecular weight of 10×103 .Fluorescence in-tensity and distribution were changed by exogenous addition of NSP 486-175 to cultured Caco-2 cells.Conclu-sion The expression vectors of pET-28a(+)-NSP4 and pET-28a(+)-NSP486-175 were successfully construc-ted and the target protein could induce [Ca2+]i imbalance.This phenomenon preliminarily indicates that the prokaryotic expressed NSP486-175 protein has biological activity and can be further used to elucidate rotavirus pathogenic mechanisms and perform vaccine research .

Action mechanism of hyperin on neonatal rat's neuron with anoxia-reoxygenation / 中国药理学通报

Aim To study the action mechanism of hyperin(Hyp) on neonatal rat's neuron with anoxia/reoxygenation(A/R).Methods The dissociated neonatal rat brain cells were subjected to 30 min of anoxia or followed 40 min of reoxygenation.Lactate dehydrogenase(LDH),malondialdehyde(MDA)and nitric oxide(NO)in the supernatant were measured.The intracellular free calcium concentration([Ca~(2+)]_i)in brain cells was assayed with Fura 2-AM method.Results Anoxia induced a significant increase of LDH in the supernatant from (62.0±13.0) U·L~(-1)(Sham group)to (116.0±16.6) U·L~(-1)(Control group,P<0.01),and reoxygenation markedly increased LDH and MDA in the supernatant from (45.6±9.2) U·L~(-1) and (9.1±0.9) μmol·L~(-1)(Sham group)to (106.0±17.4) U·L~(-1) and (16.4±2.7) μmol·L~(-1)(Control group,P<0.01),respectively.In the range of 1.0 ～ 16.0 μmol·L~(-1),Hyp markedly and concentration-dependently inhibited anoxia-or reoxygenation-evoked increases of LDH and MDA.1.0～16.0 μmol·L~(-1) Hyp not only inhibited anoxia-induced increase of NO in the supernatant and rise of [Ca~(2+)]_i in brain cells(P<0.05 or P<0.01),but also attenuated reoxygenation-evoked increases of NO and[Ca~(2+)]_i(P<0.05 or P<0.01),Hyp 16.0 μmol·L~(-1) significantly reduced NO and[Ca~(2+)]_i from (34.4±6.3) μmol·L~(-1) and (640±94) nmol·L~(-1) to (25.0±5.1) μmol·L~(-1) and (331±56) nmol·L~(-1),respectively.Conclusion The protective effect of Hyp on A/R-injured neurons may be related to the inhibition of overload of[Ca~(2+)]_i,NO release and lipid peroxidation.

Effects of aspirin on [Ca~(2+)] i and NGB in cultured neural cells of newborn rat under chemical-induced hypoxic exposure / 基础医学与临床

Objective To investigate the protective effects of aspirin on hypoxic brain neural cells of rat and the effects of extracellular calcium on the neuroprotective effect of aspirin. Methods The hypoxic cell model was established by adding Na_2S_2O_4 to the calcium or calcium free medium. Cultured primary cortical neurons of rat were pretreated with ASA in vitro. The change of intracellular free calcium and neuroglobin (NGB) were observed and analyzed by laser scanning confocal microscope. Results The expression level of [Ca~(2+)] i and NGB increased significantly in the chemical hypoxia group ( P < 0. 05 ). ASA can attenuate the increase of [ Ca~(2+) ] i and NGB in the hypoxic group and calcium-free hypoxia group(P <0. 05). Conclusion Aspirin can inhibit calcium overload and the hypoxia-induced expression of NGB, so protect rat brain cells against hypoxia.

Effect of Emodin on intracellular calcium concentration ([Ca~(2+)]i) and apoptosis of hepatic cells after simulated cold ischemia-reperfusion / 西安交通大学学报(医学版)

Objective To investigate the effect of Emodin on intracellular calcium concentration ([Ca~(2+)]i) and apoptosis of hepatic cells after simulated cold ischemia-reperfusion. Methods Glucose-oxygen deprivation, low temperature, subsequent reoxygenation and rewarming were used to induce ischemia-reperfusion injury model in cultured hepatic cells which were divided into 4 groups: control group and Emodin-treated group(100, 10 and apoptosis rate were determined by flow cytometry (FCM) respectively; the content of lactate dehydrogenase (LDH) in supernatant was tested. Results Intracellular calcium fluorescence intensity in Emodin-treated groups of high, medium and low density was 24.12±0.51, 26.35±1.34 and 39.12±1.94, respectively, which were significantly lower than 105.29±1.01 in control group(P<0.01). Apoptosis rate in Emodin-treated groups of high, (179.67±18.57)u/L in Emodin-treated groups of medium and high density respectively, which were significantly lower than (351.33±34.16)u/L in control group(P<0.01). Conclusion Emodin could reduce [Ca~(2+)]i and inhibit apoptosis of hepatic cells after simulated cold ischemia-reperfusion, thus protecting hepatic cells effectively.

Suplementación oral de calcio en adolescentes embarazadas / Calcium oral supplementation in adolescent pregnant women

Objetivo: Determinar el efecto de la administración oral de calcio en adolescentes embarazadas de bajo nivel socioeconómico sobre las concentraciones de calcio ionizado plasmático y libre intracelular. Métodos: En un ensayo clínico controlado doble-ciego aleatorizado se estudiaron 52 mujeres, 26 (50%) adolescentes embarazadas que recibieron 600 mg de calcio elemental y 26 (50%) adolescentes embarazadas que recibieron 600 mg de placebo entre las semanas 17 y 19 de embarazo. Los niveles pre-tratamiento y post-tratamiento de calcio ionizado plasmático y libre intracelular se evaluaron en ambos grupos de acuerdo con la intención de tratamiento. Resultados: Se analizaron 48 adolescentes embarazadas que completaron el estudio (24 en el grupo de calcio y 24 en el grupo de placebo). Las características sociodemográficas de los grupos fueron comparables (p=0.92) al igual que la ingesta basal de calcio en su dieta (p=0.62). La suplementación oral de calcio por intención de tratamiento no modificó las concentraciones de calcio ionizado plasmático (1.19+0.04 mmol/l vs. 1.23+0.02 mmol/l, p=0.56) ni las concentraciones del calcio ionizado libre intracelular (116.2 mmol/l vs. 89.7 mmol/l, p= 0.91), se observó un resultado semejante en las embarazadas que recibieron placebo (1.20+0.05 mmol/l vs. 1.19+0.03 mmol/l p=0.86; 116.2 mmol/l vs. 137.5 mmol/l, p=0.16, respectivamente). Conclusiones: La administración oral de calcio en adolescentes embarazadas de bajo nivel socioeconómico no modificó ni las concentraciones plasmáticas ni las intracelulares del calcio ionizado lo que podría explicar en parte el poco efecto preventivo del uso del calcio como única medida de intervención para prevenir la preeclampsia.

Objective: To determine the effect of oral administration of calcium on plasma and ionized free calcium concentration in healthy adolescent pregnant women. Methods: In a double blind randomized controlled clinical trial were recruited 48 healthy adolescent pregnant women, 24 (50%) received 600 mg of elemental calcium and 24 (50%) received 600 mg of lactose placebo. At the inclusion time the plasma and intracellular free calcium concentrations were measured by standardized techniques. One month later the plasma and intracellular free calcium concentrations in both groups were measured. Results: At the inclusion time and one month after treatment both groups were comparable for sociodemographic characteristics and the basal intake of calcium (p=0.92, p=0.62). Calcium supplementation did not modify the concentrations of plasma ionized calcium (1.19+0.04 mmol/l vs. 1.23+0.02 mmol/l, p=0.56) and the free intracellular calcium concentration (mmol/l vs. 89.7 mmol/l, p=0.91); similar effects were observed with the placebo treatment (1.20+0.05 mmol/l vs. 1.19+0.03 mmol/l p=0.86; 116.2 mmol/l vs 137.5 mmol/l, p=0.16, respectively). Conclusions: Oral administration of 600 mg of elemental calcium in adolescent pregnant women did not induce changes in the plasma and intracellular ionized free calcium concentrations and could explain in part the lack effect of this only supplementation in preeclampsia prevention.

Effect and Mechanism of Epidermal Growth Factor on Proliferation of GL15 Gliomas Cell Line / 华中科技大学学报（医学）（英德文版）

The effects of epidermal growth factor (EGF) on proliferation of G 15 glioma cells and the possible mechanisms were investigated. GFAP and EGFR expression was detected by immunohistochemical method. After the cells were treated with EGF at different concentrations, cell count method was used to determine the proliferation of glioma cells, cell cycle and apoptosis were analyzed by flow cytometry (FCM), and laser scan confocal microscope (LSCM) was used to measure the cytoplasmic free calcium. The results showed that GFAP was diffusedly expressed in GL15 cells and EGFR was over-expressed. EGF at doses of ≤ 1 ng/mL could significantly stimulate cell proliferation, cells in phase G0/G1 decreased, and those in phase S increased. EGF at doses of 10 and 100ng/ml could inhibit the cell proliferation significantly, and the apoptosis ratio in high dose of EGF group was higher than in control group. EGF could significantly induce a quick rise of intracellular free calcium, but the peak value of intracellular free calcium activated by high dose of EGF was higher than by low dose of EGF. It was suggested that EGF had a dual effect on gliomas: low dose of EGF could stimulate the cell proliferation of gliomas, but high dose of EGF could induce the cell apoptosis and inhibit the proliferation of gliomas, which might be contributed to the difference of intracellular free calcium.

Effects of aspirin on [Ca~(2+)]i and NGB in cultured neural cells of newborn rat under chemical-induced hypoxic exposure / 基础医学与临床

Objective To investigate the protective effects of aspirin on hypoxic brain neural cells of rat and the effects of extracellular calcium on the neuroprotective effect of aspirin. Methods The hypoxic cell model was established by adding Na2S2O4 to the calcium or calcium free medium. Cultured primary cortical neurons of rat were pretreated with ASA in vitro. The change of intracellular free calcium and neuroglobin (NGB) were observed and analyzed by laser scanning confocal microscope. Results The expression level of [Ca2+]i and NGB increased significantly in the chemical hypoxia group(P

The effect of Shihusan on intracellular free calcium of human retinal neural cells / 眼科

Objective To explore the effects of Shihusan on the intracellular free calcium of human retina cells and the protection from the damage of glutamate. To investigate its function and mechanism in retinal degeneration diseases, and to offer the basis on which to treat the similar disease clinically. Design Experimental study. Participants Retinal cells from normal human eye. Methods Cultivation of human retinal neural cells was perfonned. The changes of fluorescent density of intracellular free calcium of cultured cells labeled with Fluo3/AM before and after adding Shihusan and verapamil were detected with laser scanning confocal microscopy. In addition, the effect of Shihusan on calcium overload provoked by glutamic acid was observed. Main Outcome Measures The level of intracellular free calcium of retinal cells. Results The retinal cells adhered, spread and grew well in vitro. The fluorescence intensity increased 88% in glutamic acid group, decreased 14.8% and 57.3% in Shihusan group and verapamil group respectively. Shihusan couldn't decrease the intracellular Ca2+ that was increased by glutamic acid, but could inhibit the increasing tendency induced by glutamic acid. The difference was significant compared to control group (P=0.000). Conclusions Shihusan might decrease the level of intracellular free calcium in cultured human retinal cells, and resist the damage of glutamate. Its mechanism was related possibly to resisting calcium overload and inhibiting apoptosis.

Effect of Extracts from Safflower Seeds on Osteoblastic Differentiation and Intracellular Free Calcium Concentration in MC3T3-E1 Cells

Very little research has been carried out on safflower seed for the prevention and treatment of the bone deficiency diseases, including osteoporosis, which are supported by scientific evidences. In the present study, 3microliter of 0.1% dried crude extract or 2microliter of 0.1% dried aqueous fraction were shown to significantly accelerate the rate of differentiation of osteoblast. Also, the crude extract and aqueous fraction increased the [Ca2+]i of the cultured osteoblast cells: 3microliter of 0.1% dried crude extract and 2microliter of 0.1% dried aqueous fraction significantly increased the [Ca2+]i of the cultured osteoblast cells (8x104) to the extent that it deserves a considerable attention. Furthermore, the crude extract and aqueous fraction increased the [Ca2+]i of the cultured osteoblast cells, and 300microM Cd2+, specific calcium channel blocker, completely blocked the increase. Therefore, the increased [Ca2+]i of the cultured osteoblast cells by safflower seed component continued to activate calcium channel.

Comparison of ANG II-mediated Ca2+i, IP3 Production and ATPi in Isolated Renal Proximal Convoluted Tubules of Adult SHR and WKY / 대한신장학회잡지

BACKGROUND: The renin angiotensin syaimstem plays an important role in hypertension. Therefore, the purpose of this study was to investigate the comparison of responsiveness to angiotensin II (ANG II) in isolated renal proximal convoluted tubules of spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats. METHODS: Intracellualr calcium concentration ([Ca2+i) was measured using Fura- 2/AM, inositol trisphosphate (IP3) accumulation was determined by radioimmuno assay and cellular ATP content measured using the microchemilunescene method in renal proximal tubule suspension or isolated renal proximal tubules. RESULTS: When measured the ANG II-induced [Ca2+i, the young rats showed a greater response to ANG II than adult rats in both strains. The ANG II (10-7 M)-induced [Ca2+i transient in the cortical tubule suspension from adult SHR was significantly lower than that in age-matched WKY. In isolated proximal tubule segments, ANG II-induced [Ca2+i increment was only observed in S1 segments. Comparing responsiveness to ANG II in SHR and WKY, similar phenomenon was observed as experiment using tubule suspension. IP3 accumulation by ANG II also attenuated in adult SHR. The 20-minutes incubation without any exogenous substrate in proximal convoluted tubule (S1) significantly decreased cellular ATP content and ANG II (10-7 M) inhibited decrement of cellular ATP level. The effect of ANG II on cellular ATP restoration was disappeared by the treatment with losartan. CONCLUSION: From these results, the responsiveness of ANG II to AT1A receptor is attenuated in the proximal convoluted tubules of adult SHR comparing the age- mached WKY.

Effect of protopine on contraction and intracellular free calcium concentration of smooth muscle of thoracic aorta in rats / 第三军医大学学报

Objective To study the effect of protopine (Pro) on the intracellular free calcium ions of the smooth muscular cells of the thoracic aorta in rats. Methods The procedure of calcium absence-calcium addition was designed to observe the changes of the level of calcium ions in the strips of the smooth muscle of the thoracic aorta indirectly. The concentration of calcium ions in the smooth muscle of the thoracic aorta was determined with Fura-2/AM loaded SMCs. The elevation of calcium ions was induced with norepinephrine (NE). The concentration of potassium ions was observed in the presence of Pro. Results Pro significantly inhibited the NE-induced transient contract of the smooth muscle of the thoracic aorta in calcium-free medium and long-lasting contraction after the addition of calcium ions in a concentration-dependent manner. In Fura-2/AM loaded SMCs, Pro (50 ?mol/L or 100 ?mol/L) exerted no effect on the resting calcium ions but obvious effect on the NE-induced and high potassium level-induced elevation of calcium ions. In the presence of extracellular calcium ions, Pro (50 ?mol/L) decreased the NE-induced elevation of calcium ions but showed no effect on potassium-induced elevation of calcium. Pro (100 ?mol/L) significantly decreased NE-induced and high potassium level-induced elevation of calcium ions. Conclusion Pro reduces NE-induced or high potassium level-induced elevation of calcium ions in the smooth muscle of the thoracic aorta through its effect on calcium release and/or calcium influx.

Inhibition effects of radix salviae miltiorrhizae on Ca~(2+) activity promoted by angiotensin Ⅱ: a randomized control trial / 第三军医大学学报

Objective To investigate whether pharmacological serum from the rats taking radix salviae miltiorrhizae (RSM) can inhibit increase of intracellular free calcium level in hepatic stellate cells (HSCs). Methods A total of 32 healthy SD rats were divided into 4 groups. Two groups were modeled into hepatic fibrosis by 40% CCl 4 injection subcutaneously for 9 weeks and RSM were filled into the stomachs of one group (group A) but the same volume of saline into the other group (group B) twice a day for 6 d. Another two groups were only filled with RSM (group C) and saline (group D) for 6 d without modeling into hepatic fibrosis. The pharmacological serum was drawn from the inferior vena cava at 2 h after the last time of RSM or saline and used to culture HSCs at the concentration of 10% for 24 h. After HSCs were loaded with Fluo-3/AM, the effects of RSM on [Ca 2+ ] i with laser scanning confocal microscopy were examined before and after angiotensin Ⅱ treatment. Results In the activated HSCs of groups A and C, [Ca 2+ ] i decreased significantly as compared with groups B and D (P

Effects of Breviscapine on the contraction of rabbit aorta strips induced by noradrenaline and high potassium / 中国药理学通报

Aim To observe the effects of Breviscapine (Bre) on the contractions induced by noradrenaline (NA) and high potassium in rabbit aorta strips and to investigate the relationships of these effects to the changes of intracellular free calcium( i). Methods The effects of Bre on the concentration-response curves for NA and high potassium, and on the transient contractions induced by NA and caffeine in Ca 2+-free medium and the sustained contraction by NA after replenishing Ca 2+ were surveyed using rabbit aorta strips; the changes of i increased by NA and high potassium in the presence of Bre were determined using fura-2/AM loaded cultured smooth muscle cells of rabbit aorta. Results Bre shifted the concentration-response curve for NA to right in a dose-dependent manner , but shifted that for high potassium to left; it inhibited the transient contraction induced by NA and caffeine in the Ca 2+-free medium and the sustained contraction induced by NA after replenishing Ca 2+; Bre inhibited the i increased by NA, but enhanced that increased by high potassium in the smooth muscle cells of rabbit aorta. Conclusion Bre inhibits the contraction induced by NA through its inhibition effects on Ca 2+-influx and Ca 2+-release ; it enhances the Ca 2+-influx induced by high potassium, but the mechanism by which Bre enhances the high potassium inducing Ca 2+ -influx is not known.

Effects of YMⅢ on vascular contractive activities and the underlying mechanism / 中国药理学通报

Aim To investigate the effects of YMⅢ,a derivative of naftopidil, on the vascular contractive activities in rabbit aorta and to explore its vasodilative mechanisms.Methods The isotonic contractions of the thoracic aorta strips from rabbits were recorded, and the effects of YMⅢ on the concentration-response curves of noradrenaline(NA),high potassium and 5-hydroxytryptamine(5-HT)were observed.Intracellular free Ca2+([Ca2+]i)was investigated in the pressence of and the absence of YMⅢ in different conditions.Results YMⅢ(10-8,5?10-8,10-7 mol?L-1)shifted the concentration-response curve of NA with a parallel manner to right, the maximum response was unchanged and the pA2 value was 8.00; YMⅢ (10-5 mol?L-1)also shifted the concentration-response curve induced by high potassium to right but with non-parallel manner,the response was depressed and the pD′2 value was 4.26. However, YMⅢ(10-7,10-6,10-5 mol?L-1)had no statistical influence on the concentration-response curve induced by 5-HT, although it tended to depress the response of the curve at 10-5 mol?L-1.In Ca2+-free medium,YMⅢ (10-8,5?10-8 and 10-7mol?L-1) significantly inhibited the transient contraction induced by NA and the long-lasting one induced by addition of Ca2+ with a concentration-dependent manner.But even at 10-5 mol?L-1,it did not inhibit the contraction induced by caffeine.Conclusions YMⅢ may be ?-adrenergic receptor blocker.Its vasodilative mechanism may be related to:blocking ?-adrenergic receptor on cell membrane resulting in the inhibition on the influx of extracellular Ca2+ and the release of intracellular calcium.

Effects of smoking and glonoine on intracellular Ca~(2+) in vascular smooth muscle cell in rabbits with atherosclerosis / 中国药理学通报

Aim To study the effects of smoking and glonoine on intracellular free Ca2+ concentration([Ca2+]i) in vascular smooth muscle cell in rabbits with atherosclerosis,and to explore the effects of smoking on atherosclerosis and biologic action of glonoine.Methods An atherosclerosis in rabbits was produced.The vascular smooth muscle cells were isolated.The cells were loaded by Fluo-3/AM.[Ca2+]i in vascular smooth muscle cell was measured by flow cytometer(FCM).The spatial distribution and the dynamic changes of [Ca2+]i in single vascular smooth muscle cells were determined by laser scanning confocal microscopy(LSCM).Results Atherosclerosis plaques in arteriae aorta were observed and the degrees were different in various groups.[Ca2+]i in vascular smooth muscle cells in rabbits with atherosclerosis markedly increased[(48.45?5.31) vs that in saline control(38.09?2.57),P

The Role of ATP on Reactive Oxygen Species Generation and Cellular Proliferation in BV-2 Cells / 대한소아신경학회지

PURPOSE: Adenosine triphosphate (ATP) evokes several cellular responses in microglia including propagation. However, the role of the purinoceptor on ROS generation in microglia is unclear. In order to determine the action of the purinoceptor in microglia, the effects of ATP on ROS generation and cellular proliferation in BV-2 murine microglial cells were evaluated. An additional aim of this study was to investigate signal transduction pathways using several inhibitors. METHODS: The [Ca2+] was measured using Ca2+ sensitive indicator, Fura-2/AM. ROS production was observed by fluorescence-confocal microscope and cell proliferation was evaluated by counting cell number. RESULTS: ATP increased the intracellular calcium levels ([Ca2+]i) in BV-2 cells in a dose-dependent manner. This increase was attenuated by pretreatment with a calcium chelator (EGTA) and a phospholipase C (PLC) inhibitor (U-73122) while the protein tyrosine kinase (PTK) inhibitor (genistein) had no inhibitory effects. To identify the effects of the nucleotides, ROS generation was observed in the nucleotide-stimulated BV-2 cells. The treatment with 100 M ATP induced ROS generation, but 100 M adenosine and 100 M UTP did not. To investigate the signal transduction pathway in ATP-induced ROS generation, several inhibitors were pretreated before adding ATP. ATP- induced ROS production was blocked by pretreatment with either 0.5 mM EGTA or 10 M U73122 while 40 M genistein had an inhibitory effect on ATP action. Correspondingly, 40 M KN62 (CaM kinase II inhibitor), 1 M sphingosine (protein kinase C inhibitor), 1 nM DPI (NADPH oxidase inhibitor) and 50 M mepacrine (phospholipase A2 inhibitor) could suppress ATP-induced ROS generation. The effects of ATP on cell proliferation was observed 3 days after ATP treatment and its peak velocity after 4 days. NF-kB activation was observed after the cells were incubated with 0.1 mM ATP. The maximal level of NF-kB activation was obtained with 0.3 mM ATP while higher concentrations were less effective. CONCLUSION: Overall, we conclude that ATP in BV-2 cells induces ROS generation and cell propagation. The signal transduction pathways including calcium, CaM kinase II, PLC, protein kinase C, phospholipase A2 and NADPH oxidase are involved in ATP-induced ROS generation.

The Effect of CGRP on Free Calcium Concentration in Brain Cells of Hypoxic-ischemic Neonatal SD Rats / 中国医师杂志

Objective To explore the effect of calcium gene-related peptide (CGRP) on free calcium concentration in the brain cells of hypoxic-ischemic neonatal SD rats. Methods Animal model of hypoxic-ischemic cerebral injury was set up using SD rats of 7 days old. Then the rats were randomly divided into treatment group given 3?g/kg/d CGRP intraperitoneally for 3 days immediately after the model was made, and salt solution group given 0.9% NaCl solution intraperitoneally for 3 days. Normal control group received sham operation. All the rats were decapitated after 3 days and the concentration of free calcium in brain cells was measured with calcium fluorescence indicator in Fura-2Am. Results The free calcium concentration in brain cells in salt solution group was significantly higher than that in the other two groups (P