外源Ca^(2+)对金线莲组培苗生长发育的影响

以金线莲组培苗为试验材料,研究添加不同浓度(0、1.5、3、6、9 mmol/L)Ca^(2+)对金线莲组培苗的气孔细胞、农艺性状、酶活性的影响。结果表明,在1.5 mmol/L Ca^(2+)环境下培养的金线莲叶片宽大、植株也相对健壮,总体长势较好,生理生化指标体现该浓度下的金线莲各类代谢活动较为旺盛,各种关键酶的活性也比较高,抗逆性能较优,6 mmol/L Ca^(2+)环境下培养的金线莲叶片较小且幼嫩,但植株丛芽多而健壮。因此,1.5 mmol/L Ca^(2+)是相对适宜金线莲组培苗生长发育的钙环境,而6 mmol/L Ca^(2+)是相对适宜金线莲长芽扩繁的钙环境。

Relationship of Intracellular Free Ca^(2+) Concentration and Calcium-activated Chloride Channels of Pulmonary Artery Smooth Muscle Cells in Rats under Hypoxic Conditions

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.

The concentration quenching and crystallographic sites of Eu^(2+) in Ca_2BO_3Cl

A yellow phosphor, Ca2BO3CI：Eu2＋, is prepared by the high-temperature solid-state method. Under the condition of excitation sources ranging from ultraviolet to visible light, efficient yellow emission can be observed. The emission spectrum shows an asymmetrical single intensive band centred at 573 nm, which corresponds to the 4f65dl→4f7 transition of Eu2＋. Eu2＋ ions occupy two types of Ca2＋ sites in the Ca2BO3C1 lattice and form two corresponding emission centres, respectively, which lead to the asymmetrical emission of Eu2＋ in Ca2BO3C1. The emission intensity of Eu2＋ in Ca2BO3C1 is influenced by the Eu2＋ doping concentration. Concentration quenching is discovered, and its mechanism is verified to be a dipole-dipole interaction. The value of the critical transfer distance is calculated to be 2.166 nm, which is in good agreement with the 2.120 nm value derived from the experimental data.

FOLLICULO-STELLATE CELLS OF THE RAT ANTERIOR PITUITARY RESPONDED TO ANGIOTENSIN Ⅱ BY INCREASING INTRACELLULAR Ca^(2+) CONCENTRATION

Objective The main purpose of this study was to investigate whether the folliculo stellate cells (FSC) respond to angiotensin(Ang)Ⅱ by increasing intracellular free Ca 2+ concentration ([Ca 2+ ]i),and where the origin of Ca 2+ mobilization is if that has occurred.Methods Pituitary cells in primary culture were prepared from male Wister rats(250g) by a conventional method and cultured in MEM supplemented with 4% normal rat serum.After 2 days in culutre,cells were loaded with 1 μmol/L fura PE3/AM for 1 h and subjected to a Ca 2+ imaging experiment with Quanti Cell 700 system.Excitation wavelengths of 340 and 380 nm were selected by means of a computer controlled filterwheel.Results The [Ca 2+ ]i of FSC in the rat anterior pituitary was elevated by Ang Ⅱ.The elevation of [Ca 2+ ]i of FSC induced by 0.1,1.0,10 and 100 nmol/L Ang Ⅱ was (56.33±6.18)( ±s ),(117.07±36.07),(175.59±40.01) and (216.02±11.52) nmol/L,respectively.The increase of [Ca 2+ ]i of FSC induced by 100 nmol/L Ang Ⅱ was not influenced by the medium without Ca 2+ (0Ca),but significantly suppressed by thapsigargin(TG),an inhibitor of ATPase.The rate of responsive FSC to Ang Ⅱ (100 nmol/L) was 61.84% which was obviously higher than that of pituitary endocrine cells(43.49%).Conclusion The present experiment demonstrates that the FSC in the rat anterior pituitary responds to Ang Ⅱ by increasing [Ca 2+ ]i,which raises the possibility that Ang Ⅱ released from either lactotrophs or gonadotrophs affects FSC through paracrine mechanism.The elevation of [Ca 2+ ]i induced by Ang Ⅱ presents a dosage dependent relation, and is possibly because of the release of Ca 2+ from an intracellular Ca 2+ pool(s).Fashions of Ca 2+ release are relative to the concentration of Ang Ⅱ.The results indicate that Ang Ⅱ functions as a paracrine factor among pituitary cells including FSC.

Effect on apoptosis、mitochondrial membrane potential and Ca^(2+) concentration in HepG-2 by CSEO

Objective To study on the mechanism of growth inhibiting and apoptosis inducing effect of total alkaloid in the CSEO(Capparis spinosa L.essential oil,CSEO)on human hepatocarcinoma cell Line HepG-2.Methods The growth inhibiting effect of the CSEO on human hepatocarcinoma cell Line HepG-2 was measured by MTT method.Morphological observation of the HepG-2 cells was completed by fluorescence microscope.The changing of mitochondrion membrane potential induced by CSEO was observed by staining with Rhodamine123.Effect of the CSEO on intracellular Ca2+ level of the HepG-2 cells was measured by laser confocal microscope.Results The CESO has obvious growth inhibiting effect on the HepG-2 and seems to be dose-dependent,and its IC50 is 127.5 μg·mL-1.The characteristic apoptosis morpha of HepG-2 cells has been observed,and the apoptosis percentage increase to 44.447% in the 300 μg·mL-1 dosage group.In addition,the progress of cells cycle of G1 period has been blocked,and the cellular proportion in S and G2 period is decreased in the 75 μg·mL-1 and 150 μg·mL-1 dosage groups by the function of CSEO for 48 h.The mitochondria membrane potential(Δψm)effected by CESO is decreased,while the curve moves toward left.In addition,the intracellular Ca2+ level is increased by the function of CESO in the middle and high dose groups.Conclusions The CESO has obviously growth inhibiting and apoptosis inducing effect on human hepatocarcinoma cell Line HepG-2 by the mechanism of decreasing the mitochondria membrane potential and increasing the intracellular Ca2+ level.

Measurement of cytoplasmic Ca^(2+) concentration in Saccharomyces cerevisiae induced by air cold plasma

In this study, a novel approach to measure the absolute cytoplasmic Caconcentration([Ca]cyt) using the Caindicator fluo-3 AM was established. The parameters associated with the probe fluo-3 AM were optimized to accurately determine fluorescence intensity from the Ca-bound probe. Using three optimized parameters(final concentration of 6 m M probe,incubation time of 135 min, loading probe before plasma treatment), the maximum fluorescence intensity(F?=?527.8 a.u.) and the minimum fluorescence intensity(F?=?63.8 a.u.) were obtained in a saturated Casolution or a solution of lacking Ca. Correspondingly, the maximum [Ca]cytinduced by cold plasma was 1232.5 n M. Therefore, the Caindicator fluo-3 AM was successfully applied to measure the absolute [Ca]cytin Saccharomyces cerevisiae stimulated by cold plasma at atmospheric air pressure.

葛根素降低细胞内Ca^(2+)浓度并上调BDNF保护血管性痴呆大鼠海马神经细胞

目的观察葛根素对血管性痴呆(VD)大鼠海马神经细胞内Ca^(2+)浓度及脑源性神经生长因子(BDNF)的影响,探讨葛根素保护神经细胞的可能机制。方法雄性SD大鼠随机分为假手术组、模型组和葛根素干预组,采用间隔3 d结扎双侧颈总动脉法建立VD模型;术后2周用Morris水迷宫评估大鼠学习记忆能力,免疫组化和Western blotting检测大鼠海马组织BDNF的表达情况,流式细胞仪检测平均荧光强度来表示细胞内游离Ca^(2+)浓度。结果葛根素干预组Morris水迷宫逃避潜伏期显著缩短,海马BDNF表达量显著增加,海马神经细胞内Ca^(2+)浓度减低;与模型组相比,差异有统计学意义(P<0.05)。结论葛根素对VD大鼠具有神经保护作用,其作用机制可能与葛根素降低海马神经细胞内Ca^(2+)浓度及上调BDNF的表达有关。

Pcv-aCO_(2)/Ca-cvO_(2)联合血气乳酸水平指导院前创伤性休克患者早期复苏的目标

目的探讨中心静脉-动脉血二氧化碳分压差(central venous-arterial carbondioxide difference,Pcv-aCO_(2))与动脉-中心静脉血氧含量差(arterial-central venous oxygen content difference,Ca-cvO_(2))的比值(Pcv-aCO_(2)/Ca-cvO_(2))联合血气乳酸水平作为院前创伤性休克患者早期复苏目标对预后的意义。方法回顾性分析常德市第一人民医院120急救中心2021年9月—2022年9月院前接诊的145例创伤性休克患者,其中男性73例,女性72例;年龄19~78岁,平均58.4岁;道路交通伤49例,高处坠落伤28例,击打伤17例,跌倒伤27例,其他24例。在120救护车上完成动脉置管和中心静脉置管术测定Pcv-aCO_(2)/Ca-cvO_(2)值,同时采取床旁即时检验进行血气乳酸水平的监测。于休克复苏后1h(T1)按Pcv-aCO_(2)/Ca-cvO_(2)和血气乳酸值结果分为4组:A组(n=45):Pcv-aCO_(2)/Ca-cvO_(2)>1.8、乳酸水平>2mmol/L;B组(n=31):Pcv-aCO_(2)/Ca-cvO_(2)>1.8、乳酸水平≤2mmol/L;C组(n=37):Pcv-aCO_(2)/Ca-cvO_(2)≤1.8、乳酸水平>2mmol/L;D组(n=32):Pcv-aCO_(2)/Ca-cvO_(2)≤1.8、乳酸水平≤2mmol/L。比较各组间液体治疗开始时间(T0)和液体复苏后1h(T1)心率、中心静脉压、平均动脉压、中心静脉血氧饱和度水平,入院后24h及第3天急性生理与慢性健康(acute physiology and chronic health evaluation,APACHE)II和序贯器官衰竭评分(sequential organ failure assessment,SOFA)评分、住院时间、28d病死率。结果四组患者T0时心率、中心静脉压、平均动脉压、中心静脉血氧饱和度差异无统计学意义(P>0.05)。与T0相比,T1时的心率、中心静脉压、平均动脉压、中心静脉血氧饱和度比较差异有统计学意义(P<0.05)。D组在第3天的APACHE II(13.7±4.1)分和SOFA评分(5.2±2.1)分最低,住院时间最短(6.4±2.5)d,28d病死率(9.3%)最低,生存时间中位数最长,与A组比较差异有统计学意义(P<0.05)。T1时的Pcv-aCO_(2)/Ca-cvO_(2)和血气乳酸水平是28d病死率的独立预测因子。Pcv-aCO_(2)/Ca-cvO_(2)联合血气乳酸水平的受试者工作特征(ROC)曲线下面积显著大于单独Pcv-aCO_(2)/Ca-cvO_(2)或血气乳酸水平的ROC曲线下面积(P<0.05)。结论Pcv-aCO_(2)/Ca-cvO_(2)联合血气乳酸水平可预测创伤性休克患者不良结局,并为院前评估创伤性休克早期复苏的充分性提供有用信息。

对Ca^(2+)影响煤泥浮选和凝聚作用机理的认识

分析了Ca2+的作用机理,当矿浆中Ca2+浓度适中时,能强化煤泥的浮选和凝聚效果.Ca2+与水分子生成的六水络合物[Ca(H2O)6]2+在颗粒表面吸附或与气泡吸附,破坏双电层,使颗粒表面和气泡表面疏水性提高,从而改善煤泥浮选和凝聚效果.钙离子在煤泥水系统中循环,生产中节省药剂费用.Ca2+浓度小时效果不明显;Ca2+浓度较大时,与水生成的亲水性物质在颗粒表面上小部分吸附或沉淀,恶化浮选效果.但由于静电吸引,凝聚效果变好;硫酸钙用量太大时,生成的亲水性物质和没溶的硫酸钙会在颗粒面上大面积吸附、沉淀,颗粒间产生静电排斥,凝聚效果变差.

黄芪多糖对缺血缺氧脑损伤大鼠脑组织Ca^(2+)和兴奋性氨基酸的影响

目的:探讨黄芪多糖对缺血缺氧脑损伤大鼠脑组织中Ca^(2+)和兴奋性氨基酸水平的影响。方法:60只大鼠随机分成3组:假手术组、模型组、黄芪多糖组,每组20只。采用改良Longa线栓法制备大鼠中动脉栓塞(MCAO)模型。黄芪多糖组于脑缺血前30 min及术后8 h按1g·kg^(-1)分别腹腔注射给药1次,模型组和假手术组于同时间腹腔注射等容量生理氯化钠溶液。3组均于造模24 h后断头取血2 mL,分离血清,并取全脑,测脑组织的Ca^(2+)含量、脑组织和血清中谷氨酸(Glu)和天门冬氨酸(Asp)的含量。结果:模型组脑组织Ca^(2+)、脑组织和血清Glu和Asp含量均明显高于假手术组(P＜0．01),黄芪多糖组这些指标的变化则显著低于模型组(P＜0．01或P＜0．05)。结论:黄芪多糖对缺血缺氧脑损伤大鼠具有脑保护作用,其机制可能与降低脑内Ca^(2+)和兴奋性氨基酸的含量有关。

天山乌鲁木齐河源1号冰川积累区气溶胶和表层雪中可溶性矿物粉尘的变化特征及相互关系——以Ca^(2+)、Mg^(2+)为例

对天山乌鲁木齐河源1号冰川(以下简称1号冰川)积累区海拔4130 m处12个月、每周1次的气溶胶和表层雪样品进行了分析.结果表明,1号冰川气溶胶与表层雪中Ca2+、Mg2+的平均浓度均在夏季最高,冬季最低.气溶胶中Ca2+、Mg2+浓度变化规律极其相似,二者在一年内出现两次峰值,第1次出现在春季,第2次出现在夏末秋初.表层雪中这两种离子浓度变化趋势也相似,峰值均出现在夏季,且Ca2+浓度峰值的出现稍早于Mg2+,二者浓度在冬季都有所升高,尤其Ca2+更为显著.气溶胶和表层雪中对应离子间在整体变化趋势上较为相似,且在日时间尺度上的对应关系有显著的特点.相应离子的对应关系,可能受粉尘微粒的溶解、离子的清除比率、离子的淋溶强弱等性质的影响.

固化土孔隙液Ca(OH)_2饱和度对强度的影响

物理力学性质相同的土样掺加等量水泥制备的固化土强度通常有很大差别。通过选取几组物理力学性质相近的典型土样,掺加不同比例的水泥和Ca(OH)2制备成固化土,测定了固化土孔隙液离子浓度和固化土强度。研究表明:由于土样对Ca(OH)2的消耗,可能导致固化土孔隙液中Ca(OH)2不饱和,进而影响了水化硅酸钙的生成量;不同土样对Ca(OH)2消耗量不同,导致在掺加同量水泥时水化物的生成量不同,因此固化土强度不同。土样各种化学性质的影响因素对固化土强度的影响可归结为对孔隙液Ca(OH)2饱和度的影响。对于物理力学性质相近的土样,在满足孔隙液Ca(OH)2饱和的条件下,掺入同量水泥的固化土强度相同。

慢性染铅对大鼠海马区神经细胞Ca^(2+)浓度及Ca^(2+)-ATP酶活性的影响

目的：观察慢性染铅对大鼠海马区神经细胞Ｃａ２＋浓度及Ｃａ２＋－ＡＴＰ酶活性的影响。方法：用０．１５％醋酸铅饲养大鼠建立慢性染铅动物模型，参照Ｄｉｌｄｙ法和徐友涵法测定海马神经细胞Ｃａ２＋浓度及Ｃａ２＋－ＡＴＰ酶活性。结果发现：细胞内Ｃａ２＋浓度，染铅组（２０３．８３±３０．５０）ｎｍｏｌ／Ｌ，对照组（９７．６２±１９．８３）ｎｍｏｌ／Ｌ，ｔ＝８．３１Ｐ＜０．００５；Ｃａ２＋－ＡＴＰ酶活性，染铅组（３２６．４２±４０．０６）ｎｍｏｌ（Ｐｉ）·ｍｇ－１·ｍｉｎ－１，对照组（２５３．０７±２５．４０）ｎｍｏｌ（Ｐｉ）·ｍｇ－１·ｍｉｎ－１，ｔ＝３．５４，Ｐ＜０．０１。结论：慢性染铅可使大鼠海马区神经细胞内Ｃａ２＋浓度升高。

针刺人体足三里上巨虚穴对胃经其他腧穴处Ca^(2+)浓度影响的试验观察

[目的 ]观察针刺足三里、上巨虚对胃经其他腧穴处Ca2 + 浓度的影响。 [方法 ]以Ca2 + 选择性塑料针型电极 ,刺入足三里、解溪、阴市及其旁开点 ,测试Ca2 + 浓度 ,然后将针刺入上巨虚、足三里 ,动态观察测试点Ca2 + 浓度。[结果 ]针刺上巨虚、足三里 ,可提高胃经其他腧穴处Ca2 + 浓度。 [结论 ]针刺调气与调节经脉线上的Ca2 + 浓度可能存在相关性。

盐度和Ca^(2+)浓度对中国明对虾稚虾耗氧率的影响

设计双因子实验研究了水温25.0℃±0.5℃下,盐度(5,15,30)和Ca2+质量浓度(175,350,700,1 400,2 800 mg/L)对中国明对虾(Fenneropenaeus chinensis)稚虾耗氧率的影响,实验对虾的湿体质量为0.301 g±0.041 g。实验结果表明:(1)不同盐度下,中国明对虾稚虾耗氧率的大小顺序为R5>R30>R15。其中,盐度15下对虾的耗氧率显著低于盐度5和30下的耗氧率(P<0.05);(2)不同Ca2+质量浓度下,中国明对虾稚虾耗氧率的大小顺序为R2 800>R175>R700>R1 400>R350。其中,Ca2+质量浓度为350 mg/L组对虾的耗氧率显著低于其它处理组,Ca2+质量浓度为2 800 mg/L组对虾的耗氧率显著高于其它处理组(P<0.05),而Ca2+质量浓度为175,700和1 400 mg/L组间对虾的耗氧率差异不显著(P>0.05);(3)盐度和Ca2+质量浓度的交互作用显著影响中国明对虾稚虾的耗氧率(P<0.05)。

高钾离子引起PC12细胞内游离Ca^(2+)浓度升高的机制

目的：分析高钾离子（Ｋ＋）引起ＰＣ１２细胞内游离钙离子浓度（［Ｃａ２＋］ｉ）升高的可能机制。方法：利用ＭｉｒａＣａｌＩｍａｇｅＳｙｓｔｅｍ检测［Ｃａ２＋］ｉ，Ｃａ２＋荧光探针为Ｆｕｒａ－２／ＡＭ。结果：（１）ＫＣｌ浓度为３０～１００ｍｍｏｌ／Ｌ时，可剂量依赖性地诱导ＰＣ１２细胞［Ｃａ２＋］ｉ升高；（２）在细胞外无Ｃａ２＋时，高Ｋ＋对ＰＣ１２细胞［Ｃａ２＋］ｉ无影响；（３）Ｌ－型电压门控钙通道阻滞剂维拉帕米、地尔硫和硝苯地平的浓度分别为５×１０－５，１×１０－４和５×１０－３ｍｏｌ／Ｌ时，可完全阻断高Ｋ＋诱导的ＰＣ１２细胞［Ｃａ２＋］ｉ升高，但Ｎ－型电压门控钙通道阻滞剂ω－ｃｏｎｏｔｏｘｉｎＧＶＩＡ在浓度为１×１０－６ｍｏｌ／Ｌ时，对高Ｋ＋诱导的ＰＣ１２细胞［Ｃａ２＋］ｉ升高没有影响；（４）５×１０－５ｍｏｌ／Ｌ维拉帕米对细胞外由无Ｃａ２＋到有Ｃａ２＋过程引起的［Ｃａ２＋］ｉ升高无抑制作用。结论：高Ｋ＋引起ＰＣ１２细胞［Ｃａ２＋］ｉ升高以细胞质膜上Ｌ－型电压门控Ｃａ２＋通道开放为基础。

人参皂苷Rg_1对H_2O_2诱导的HT22细胞凋亡及胞内Ca^(2+)变化的影响

目的研究人参皂苷Rg_1对H_2O_2诱导的HT22细胞凋亡及胞内Ca^(2+)浓度变化的影响。方法以0、6.25、12.5、25、50、100μg/L人参皂苷Rg_1预处理细胞24 h,采用Ca^(2+)荧光染料探针Fluo-3/AM负载细胞1 h后,50 mmol/L H_2O_2刺激细胞,多功能酶标仪测定荧光强度,激光共聚焦显微镜实时监测[Ca^(2+)]i变化,Hoechst 33258染色检测细胞凋亡。结果 H_2O_2可诱导细胞内Ca^(2+)浓度增加(P<0.01),并增加细胞凋亡率(P<0.01)。不同浓度人参皂苷Rg_1可呈剂量依赖性的抑制H_2O_2诱导的HT22[Ca^(2+)]i增加(P<0.01),抑制细胞凋亡(P<0.01),以50μg/L的作用为最强(P<0.01)。结论人参皂苷Rg_1可通过降低H_2O_2诱导的HT22细胞内Ca^(2+)水平的升高,抑制氧化应激引起的细胞凋亡。

Ca^(2+)浓度对膨润土掺砂混合土渗透性能的影响

垃圾填埋场底部铺设含黏土或膨润土掺砂混合土的防渗系统,防止渗滤液流入地下污染周边环境。采用模型试验研究Ca^(2+)离子浓度和基础局部沉降对膨润土掺砂混合土渗透特性的影响。试验结果表明Ca^(2+)浓度对膨润土掺砂混合土的渗透性能有较大影响,渗透液中Ca^(2+)浓度超过一定值后混合土渗漏;Ca^(2+)离子浓度与发生渗透时间之间有很大关系,浓度越高发生渗透的时间越短;同样沉降量条件下,含Ca^(2+)离子溶液渗透的混合土均发生渗漏,而用蒸馏水作渗透液的没有出现渗漏;钠基膨润土遇Ca^(2+)离子溶液后,当Ca^(2+)离子浓度大于两倍Na+就会发生离子交换,钠基膨润土转化为钙基膨润土,混合土的防渗性能下降。因此开展Ca^(2+)离子浓度对膨润土掺砂混合土渗透特性的研究具有较好的理论和实际意义。

大黄酸对IL-2诱发T淋巴细胞增殖和细胞[Ca^(2＋)]_i变化的作用

研究大黄酸对IL-2引起大鼠T淋巴细胞增殖和细胞内[Ca^(2+)]_i变化的影响.采用MTT法检测细胞增殖,用单细胞钙成像系统记录胞内游离Ca^(2+)浓度([Ca^(2+)]_i).结果表明,大黄酸对IL-2引起的细胞增殖有显著抑制作用,且抑制效果与剂量有关;IL-2引起[Ca^(2+)]_i升高,并持续维持高[Ca^(2+)]_i水平,[Ca^(2+)]_i升高的机制包括胞内Ca^(2+)释放和胞外Ca^(2+)内流;大黄酸显著抑制IL-2引起的[Ca^(2+)]_i升高.结果提示大黄酸可抑制T淋巴细胞增殖,作用机制可能与抑制细胞内[Ca^(2+)]_i升高相关.

1,25-(OH)_2D_3对肺纤维化大鼠肺泡Ⅱ型上皮细胞中Ca^(2+)浓度和PI3K/AKT/mTOR通路的影响

目的特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是一种慢性炎症性疾病,病因不明,缺乏有效的治疗方法。文中旨在探讨肺泡Ⅱ型上皮细胞中Ca^(2+)和PI3K/AKT/mTOR通路在大鼠IPF中的作用,以及1,25-(OH)_2D_3对Ca^(2+)浓度和PI3K/AKT/mTOR通路的影响。方法 150只雄性SD大鼠随机分为:预防组(对照组Ⅰ、模型组Ⅰ、给药组Ⅰ,每组20只)和治疗组(对照组Ⅱ、模型组Ⅱ、给药组Ⅱ,每组30只)。对照组Ⅰ/Ⅱ行气管暴露手术,气管内给以200μL/只的无菌等渗盐水,并分别于第2和14天开始腹腔注射等渗盐水(200μL/只);模型组Ⅰ/Ⅱ气管内灌注博来霉素(5 mg/kg),并分别于手术后第2和14天开始腹腔注射维生素D3的溶剂(0.1%乙醇和99.9%的丙二醇,1μL/g体重);给药组Ⅰ/Ⅱ气管内灌注博来霉素(5 mg/kg),并分别于手术后第2和14天开始腹腔注射1,25-(OH)_2D_3(2μg/kg体重)。大鼠气管内注射博来霉素建立IPF模型,给药组腹腔注射1,25-(OH)_2D_3进行预防和治疗。检测各组大鼠肺组织中羟脯氨酸的含量,分离肺泡Ⅱ型上皮细胞并用Fluo-3AM荧光负载,激光共聚焦显微镜检测细胞内Ca^(2+)浓度。RT-PCR方法检测PI3K、AKT、mTOR mRNA的表达水平。结果模型组Ⅰ/Ⅱ和给药组Ⅰ/Ⅱ中大鼠肺组织中羟脯氨酸的含量、肺泡Ⅱ型上皮细胞内Ca^(2+)浓度以及PI3K、AKT、mTOR mRNA表达,在各时间点与相应对照组Ⅰ/Ⅱ相比均明显升高(P<0.05或P<0.01);给药组Ⅰ/Ⅱ与模型组Ⅰ/Ⅱ相比,上述指标均有显著降低(P<0.05或P<0.01)。模型组Ⅰ/Ⅱ和给药组Ⅰ/Ⅱ中Ca^(2+)浓度与PI3K、AKT、mTOR mRNA表达之间具有显著正相关(r=0.598 8、r=0.623 0、r=0.6603,P<0.01;r=0.7012、r=0.6323、r=0.7403,P<0.01)。结论 PI3K-AKT-mTOR通路在大鼠IPF的发生发展中起重要作用,1,25-(OH)_2D_3可以降低肺泡Ⅱ型上皮细胞内Ca^(2+)的浓度,抑制PI3K-AKT-mTOR通路,进而抑制IPF的发生发展。