Effects of Iptakalim on intracellular free calcium concentration of cultured rabbit pulmonary arterial smooth muscle cells

Objective:To explore the effects of Iptakalim on intracellular free calcium concentration and on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1(ET-1) in vitro. Methods:A cell culture model, [3H]-thymidine([3H]-TdR) incorporation test and confocal microscope were used to observe proliferation and intracellular free calcium concentration([Ca2+]i) of rabbit PASMC induced by ET-1 in vitro. Results:The value of [3H]-TdR incorporation in ET-1 group was increased 1.468 times higher than that in control group. Iptakalim at the concentration of 10-7mol/L,10-6 mol/L,10-5 mol/L lowered [3H]-TdR incorporation by (19.8±4.6)%, (41.2±9.5)%, (54.7±10.1)%, respectively, compared with the value of the cells treated with ET-1(P＜0.01); The intracellular fluorescence intensity of PASMC in ET-1 group was increased from 73.70±10.12 to 143.84±28.23, significantly higher than that in control group(P＜0.01); whereas with Iptakalim,the fluorescence intensity(FI) was only increased from 74.30±10.20 to 86.03±9.82, significantly lower than that in ET-1 group(P＜0.01). Conclusion:Iptakalim inhibited proliferation of PASMC and decreased intracellular free calcium concentration of cultured rabbit PASMC induced by ET-1.     

不同参数次声对心肌细胞钙离子的影响

目的：观察不同参数次声对大鼠心肌 细胞钙离子浓度的影响。方法：用8 Hz的90、130 dB次声分别作用于大 鼠1、7、14、21和28 d，每日2 h，观察大鼠心肌细胞钙离子浓度的变化。结果:与对照组比较，次声作用组大鼠心肌细胞钙离子浓度随时间延长及声压级水平升高 而逐渐增加（P<0.01）。结论：次声可引起大鼠心肌细胞钙离子浓 度的变化，其变化与次声暴露参数有关。     

Subcellular gradients of intracellular free calcium concentration in isolated lacrimal acinar cells

The spatial distribution of intracellular free calcium concentration ([Ca²⁺]_i) was measured in small clusters of isolated rat lacrimal acinar cells by imaging the fluorescence of the Ca²⁺-sensitive dye fura-2. In the absence of extracellular Ca²⁺, stimulation with acetylcholine (ACh) caused an increase in [Ca²⁺]_i, due to release of intracellular Ca²⁺ stores, which was maximal at the luminal pole of the cell. In contrast, the organellar Ca²⁺-ATPase inhibitor 2,5-di(tert-butyl)-hydroquinone caused an increase in [Ca²⁺]_i, which was most marked in the basolateral region of the cell. When the cells were stimulated with ACh in a medium containing Ca²⁺, the gradients of [Ca²⁺]_i (with [Ca²⁺]_i most elevated at the luminal pole) were maintained for the duration of agonist stimulation. The possible implications of these results concerning the location and identity of intracellular Ca²⁺ stores, and the location of the sites that underlie agonist-stimulated Ca²⁺ influx, are considered. In particular, it seems likely that intracellular inositol-1,4,5-trisphosphate (InsP₃) binding sites may be concentrated in the luminal region of the cell. It is not clear, however, whether this implies that there is a distinct luminally located InsP ₃-sensitive organelle.     

Extracellular magnesium regulates intracellular free Mg2+ in vascular smooth muscle cells

Summary Regulatory effects of extracellular magnesium ions ([Mg²⁺]_o) on intracellular free ionized magnesium ([Mg²⁺]_i) were exmained in cultured vascular smooth muscle cells (VSMCs) fromrat aorta by digital imaging microscopy using the Mg²⁺ fluorescent probe, Mag-fura-2. With normal Mg²⁺(1.2 mM)-containing incubation media, [Mg²⁺]_i in VSMCs was 0.63±0.09 mM. The ratio of [Mg²⁺]_i/[Mg²⁺]_o was 0.52±0.07. Elevation of [Mg²⁺]o up to 4.8 mM induced consistent increments in [Mg²⁺]_i (to a mean values of 1.63±0.08 mM) in 5 min and lowered the ratio of [Mg²⁺]_i/[Mg²⁺]_o to 0.34±0.02. Our data suggest that [Mg²⁺]_o can regulate [Mg²⁺]_i, which may be related to its effects on intracellular Ca²⁺ ([Ca²⁺]_i) and tone of VSMCs.     

超氧阴离子自由基对大鼠肝卵圆细胞胞内自由钙浓度的影响

采用激光共聚焦扫描显微镜,观察黄嘌呤黄嘌呤氧化酶反应系统（Ｘ／ＸＯ）生成不同浓度的超氧阴离子自由基（Ｏ２）致培养的大鼠肝卵圆细胞（ＷＢ细胞）胞质内钙浓度的变化,结果发现：仅小剂量的Ｏ２引起胞质内钙浓度升高,约３０Ｓ后达到峰值,６０ｓ后恢复正常。部分细胞观察到数次钙浓度间断升高、幅度逐渐下降的现象。超氧化物歧化酶（ＳＯＤ）可抑制此变化,过氧化氢酶（ＣＡＴ）无效果,细胞在无钙液中观察仍出现钙峰,但受     

镁对大鼠缺氧再给氧心肌细胞内游离钙的影响

目的和方法：用ＡＣＡＳ５７０粘附式细胞仪，以荧光素染色法观察镁（Ｍｇ２＋）对体外培养乳鼠心肌细胞内游离钙（Ｃａ２＋）的影响及对缺氧再给氧时细胞内Ｃａ２＋作用。结果：细胞外Ｍｇ２＋降至０３ｍｍｏｌ·Ｌ－１，细胞内Ｃａ２＋荧光强度上升速度加快，达到稳定所需时间延长，出现Ｃａ２＋振荡曲线。增加Ｍｇ２＋浓度可使细胞内Ｃａ２＋降低。Ｍｇ２＋还可以显著减少缺氧再给氧时细胞内Ｃａ２＋，Ｐ＜００１。结论：细胞外低Ｍｇ２＋可导致细胞内Ｃａ２＋增加，Ｍｇ２＋有维持正常心肌细胞内Ｃａ２＋稳定性及拮抗缺氧再给氧时细胞内Ｃａ２＋超载作用     

IL—2对神经元NMDAR1m RNA表达和细胞内钙浓度的影响

Ｎ－甲基－Ｄ－天门冬氨酸（ＮＭＤＡ）受体和细胞内游离钙浓度（［Ｃａ２＋］ｉ）的变化与神经元的兴奋性关系密切。本文报道以大鼠大脑皮层神经元为研究对象，通过Ｎｏｒｔｈｅｒｎ印迹杂交并以Ｆｕｒａ－２作为Ｃａ２＋荧光指示剂，观察了外源性白细胞介素－２（ＩＬ－２）对ＮＭＤＡ受体１型亚单位（ＮＭＤＡＲ１）ｍＲＮＡ表达量及［Ｃａ２＋］ｉ的影响。结果显示：不同浓度的ＩＬ－２（１～２００Ｕ／ｍｌ）作用于原代培养的胚胎大鼠大脑皮层神经元６小时后其ＮＭＤＡＲ１ｍＲＮＡ表达量明显增加，并与ＩＬ－２浓度呈正相关关系。当其浓度为２５～２００Ｕ／ｍｌ时，ＮＭＤＡＲ１ｍＲＮＡ表达量增加４４．３％～２１９．７％（Ｐ＜０．０５）。ＩＬ－２（１～２００Ｕ／ｍｌ）与新生大鼠大脑皮层神经元共同孵育５～１０分钟后，［Ｃａ２＋］ｉ增加２７．１％～９４．２％（Ｐ＜０．０５）。钙通道阻断剂ｎｉｆｅｄｉｐｉｎｅ可完全阻断ＩＬ－２引起的［Ｃａ２＋］ｉ升高，而ＮＭＤＡ受体拮抗剂ＭＫ－８０１无此作用。本文结果提示：外源性ＩＬ－２具有兴奋性神经调质样作用，可能参与或介导了神经兴奋毒性作用和惊厥性疾病的发生与发展过程。     

慢性缺氧对大鼠肺动脉平滑肌细胞胞内钙的影响及其机制研究

目的:研究慢性缺氧对大鼠肺动脉平滑肌细胞(PASMCs)胞内钙浓度(［Ca²⁺］_i)的影响及L-型钙通道和胞内钙库的作用,为缺氧性肺动脉高压(HPH)发病机制的进一步研究提供理论依据。 方法:复制大鼠缺氧性肺动脉高压动物模型，利用Fura－2/AM钙离子成像方法测定PASMCs在不同钙离子浓度细胞外液及L-型钙通道阻滞剂nifedipine和IP3R钙通道抑制剂肝素干预前后 ［Ca²⁺］_i变化。 结果:(1)缺氧＋含钙外液组PASMCs ［Ca²⁺］_i 显著高于对照＋含钙外液组（P<0.05）。缺氧＋含钙外液组PASMCs ［Ca²⁺］_i显著高于缺氧＋无钙外液组（P<0.05）。(2)缺氧nifedipine组PASMCs［Ca²⁺］_i在加药前后无显著差异（P>0.05）。（3）缺氧未干预组与缺氧肝素组PASMCs ［Ca²⁺］_i无明显差异（P>0.05）。 结论:慢性缺氧可使PASMCs的［Ca²⁺］_i增加。慢性缺氧引起［Ca²⁺］_i增加可能与细胞外钙内流有关，L-型钙通道和IP3R钙通道在调节［Ca²⁺］_i的过程中可能不独立发挥作用。     

心房肽对高血压模型鼠（SHR）免疫细胞内钙离子浓度的影响

本文探讨了心房肽对自发性高血压大鼠免疫细胞内钙离子浓度的影响,结果表明,心房肽可直接促进大鼠胸腺、脾及淋巴结细胞内的钙离子浓度,亦能协同ConA促进大鼠脾细胞及T细胞内Ca~(2+)浓度的增加,但却不能影响B细胞的Ca~(2+)含量.心房肽还能协同IL-2促进经ConA诱导的大鼠淋巴母细胞内Ca~(2+)浓度的增加。同时发现自发性高血压大鼠免疫细胞心房肽所增加的Ca~(2+)浓度较正常血压对照鼠为低.     

虎杖甙对正常人血管平滑肌细胞内钙和膜电位的调节作用

目的和方法：观察虎杖甙（ＰＤ）对人脐带动脉平滑肌细胞（ＶＳＭＣ）内游离钙、细胞膜电位的变化,以探讨ＰＤ对血管平滑肌的调节机制。用Ｆｌｕｏ－３－ＡＭ、ＤｉＢＡＣ４（３）标记培养的ＶＳＭＣ,在激光共聚焦显微镜上测定细胞内游离钙和膜电位变化。结果：给ＰＤ（０５ｍｍｏｌ／Ｌ）１０ｍｉｎ后,ＶＳＭＣ内游离钙浓度升高５６％±５６％。当ＰＤ加入前用维拉帕米和ＥＧＴＡ预处理后,则游离钙不再升高;ＥＧＴＡ和肝素预处理也抑制ＰＤ的升钙作用,而ＥＧＴＡ和普鲁卡因预处理则使细胞内钙显著升高。ＰＤ还可使ＶＳＭＣ膜电位去极化,加入钠通道阻断剂河豚毒素（２５μｍｏｌ／Ｌ）可完全阻断ＰＤ的去极化作用：加甲氰咪胍、维拉帕米、优降糖和利及丁预处理不能阻断ＰＤ去极化作用。结论：：ＰＤ可通过细胞外钙内流来增加细胞内游离钙浓度,并促进细胞外钠离子内流而导致细胞去极化     

两型TNF-α的细胞毒效应与靶细胞内Ca2+浓度变化的关系

目的 :比较分泌型TNF α(S TNF α)和跨膜型TNF α(TM TNF α)发挥细胞毒效应时 ,引起靶细胞内Ca2 浓度的变化。方法 :采用生物学活性检测法 ,观察两型TNF α对不同靶细胞的杀伤效应 ;用Fura 2检测细胞内Ca2 浓度的变化。结果 :TM TNF α可杀伤实验所用 6株靶细胞 ;而S TNF α则仅对其中两株有细胞毒效应。两型TNF α杀伤靶细胞时 ,均伴有明显的Ca2 浓度升高。用钙螯合剂EGTA(10mmol/L)预先处理靶细胞30min ,只能降低S TNF α作用的靶细胞内的Ca2 浓度 ,并使其细胞毒效应明显减弱 (P <0 .0 1) ;对TM TNF α无影响。结论 :两型TNF α发挥细胞毒效应时 ,均可引起靶细胞内钙离子的重分布 ,导致靶细胞内Ca2 浓度的升高 ,但S TNF α的作用还可能与促进胞外Ca2 内流有关     

Interactions between membrane potential and intracellular calcium concentration in vascular smooth muscle

The intracellular calcium concentration is a major determinant of vascular tone. In the steady state it is regulated mainly by membrane potential. At the same time, several mechanisms regulating the calcium concentration, including the membrane potential, are influenced by the intracellular calcium concentration itself. There are thus multiple possible positive and negative feedback loops involved in calcium regulation. This review gives a brief overview of the different mechanisms involved, including calcium-dependent ion channels, exchangers, and ATPases, and discusses their role in agonist-mediated responses, in relation primarily to studies on the portal vein and mesenteric small arteries.     

Effects of endurance training on intracellular calcium concentration in T lymphocytes

The purpose of the present study was to determine whether 12 months of endurance training reduced [Ca²⁺]i in T helper (CD4⁺) lymphocytes in trained (TR) men compared to untrained (UT). Fourteen trained (Ironman triathletes) and nine untrained (sedentary) men volunteered for the study. The TR group averaged 12 km of swimming, 300 km of cycling and 60 km of running per week during the year. Resting blood samples were taken from TR (VO_2peak 64 ± 2 ml kg⁻¹ min⁻¹) and UT (VO_2peak 42 ± 2 ml kg⁻¹ min⁻¹) subjects every 4 weeks for 52 weeks (October 1, 1999–October 1, 2000). Leukocyte concentration was measured using a full blood count. Unstimulated CD4⁺ lymphocytes were separated and analysed for changes in free ([Ca²⁺]i) and total ([Ca²⁺]t) calcium using flow cytometry. There were no significant differences in leukocyte concentration between UT and TR groups. There were significant differences between TR and UT in [Ca²⁺]i (October B and November), and [Ca²⁺]t (January and March). There were also significant sequential monthly changes in both [Ca²⁺]i and [Ca²⁺]t for TR and UT groups during the study. Significant increases in [Ca²⁺]i and [Ca²⁺]t during summer (January and March) for both TR and UT groups suggest an increase in intracellular signalling during hot weather. [Ca²⁺]i and [Ca²⁺]t were significantly lower in TR lymphocytes during November and March, suggesting that endurance training during warmer months may decrease [Ca²⁺]i through altered intracellular signalling, possibly to maintain lymphocyte function during heat stress.     

过氧化氢对乳鼠心肌细胞内游离钙浓度的影响及牛磺酸的拮抗作用

目的:研究过氧化氢(H₂O₂)对心肌细胞i的影响,以及牛磺酸对H₂O₂诱导钙超载的拮抗作用。方法:采用SD大鼠乳鼠进行心肌细胞培养,实验分4组:①正常对照组;②H₂O₂组:加入终浓度为100μmol/L的H₂O₂;③H₂O₂＋牛磺酸(同时)组:牛磺酸30mmol/L与H₂O₂100μmol/L同时加入;④H₂O₂＋牛磺酸(先后)组:先加入终浓度为100μmol/L的H₂O₂,2min后再加20mmol/L的牛磺酸。以Fluo-3/AM荧光指示剂负载,应用激光共聚焦显微镜技术,分别于加入H₂O₂后即刻与15min,检测i变化。结果:对照组心肌细胞内荧光强度和荧光光密度值较低。H₂O₂加入后即刻,细胞内荧光光密度值开始增加,15min后细胞内荧光强度和荧光光密度值显著高于对照组(P＜0.05)。而H₂O₂＋牛磺酸(同时)组细胞内荧光光密度值显著低于H₂O₂组(P＜0.05vsH₂O₂组);H₂O₂＋牛磺酸(先后)组细胞内荧光光密度值显著低于H₂O₂组(P＜0.05vsH₂O₂组)。结论:H₂O₂可引起心肌细胞内钙超载;牛磺酸能显著减轻H₂O2诱导的心肌细胞内Ca²⁺超载。     

复方丹参滴丸对缺氧心肌细胞内钙离子平均荧光强度的影响

目的:探讨复方中药丹参滴丸对缺氧/复氧心肌细胞的保护作用。方法:培养的乳鼠心肌细胞,用钙探针Fluo-3/AM染色,利用激光扫描共聚焦显微镜观察心肌细胞缺氧/复氧及在复方丹参滴丸保护作用下心肌细胞内钙离子荧光强度变化。结果:缺氧加丹参保护组,细胞内钙离子荧光强度(1217.78±312.07)明显低于单纯缺氧组(1509.43±508.58);缺氧复氧加丹参组,细胞内钙离子荧光强度为(1567.91±577.61),亦较缺氧再给氧组(1617.6±477.53)低。结论:复方丹参滴丸对缺氧心肌细胞有明显保护作用。     

The intracellular concentration of free magnesium in extensor digitorum longus muscles of the rat

Magnesium-sensitive microelectrodes were used to measure the intracellular concentration of free Mg2+, [Mg2+]f, in rat extensor digitorum longus muscles in vitro at 30 degrees C. The intracellular activities of Na+ and K+ were also determined so that allowance could be made for the interference from these ions with the Mg2+ electrode response. The mean value for [Mg2+]f based on twenty-six measurements in twelve muscles was 0.47 mM.     

天麻钩藤饮对SHR血清Ca2+浓度及血管平滑肌细胞钙通道的影响

目的：探讨天麻钩藤饮对自发性高血压大鼠(SHR)的血管平滑肌细胞钙通道电生理特征的影响，以期进一步阐明天麻钩藤饮对血压干预的作用机制。方法:选用12周龄自发性高血压雄性大鼠45只，随机分为5组，即天麻钩藤饮组（A组）、天麻钩藤饮去石决明组（B组）、硝苯地平组（C组）、石决明组（D组）、生理盐水对照组（E组）。治疗4周后，测定血清游离钙浓度；用全细胞模式膜片钳技术记录分析血管平滑肌细胞L型电压依赖性钙通道的特性。结果:用药前后天麻钩藤饮组和硝苯地平组血清游离钙浓度改变没有统计学意义(P>0.05)，天麻钩藤饮去石决明组、石决明组、生理盐水组血清游离钙浓度低于用药前 (P<0.05) ，以生理盐水组最明显(P<0.01)。天麻钩藤饮组、硝苯地平组有明显减少血管平滑肌细胞ICa-L内流的作用，石决明组作用较弱，天麻钩藤饮去石决明组、生理盐水组没有减少血管平滑肌细胞ICa-L内流的作用。结论:天麻钩藤饮可以提高血清游离钙离子浓度。天麻钩藤饮有明显的阻滞血管平滑肌细胞L型钙离子通道的作用，这可能是其降压作用机制之一。     

氢氟酸烧伤中毒对兔外周血单个核细胞凋亡与胞内钙浓度的影响

目的: 研究氢氟酸烧伤中毒对兔外周血单个核细胞(PBMC)早期凋亡百分率和胞内游离钙浓度([Ca²⁺]_i)的影响。方法: 用流式细胞仪检测兔烧伤染毒前后外周血单个核细胞的Annexin V变化, 以观察其早期凋亡百分率。用Fluo-3/Am荧光探针观察烧伤染毒前后外周血单个核细胞内Ca²⁺平均荧光强度值的变化, 以观察细胞内[Ca²⁺]_i的变化。 结果: 12只烧伤中毒兔外周血单个核细胞早期凋亡百分率显著增加, 烧伤染毒前后比较P<0.01。而12只烧伤中毒兔中8只染毒后1 h外周血单个核细胞内[Ca²⁺]_i显著降低, 烧伤染毒前后比较P<0.05。其余4只却表现[Ca²⁺]_i染毒前后比较P>0.05。 结论: 本实验氢氟酸烧伤中毒使兔外周血单个核细胞早期凋亡百分率显著增加, 外周血单个核细胞内[Ca²⁺]_i却显著降低。提示氢氟酸烧伤中毒引导的细胞凋亡并非细胞内[Ca²⁺]_i增加所引发。     

慢性肾衰大鼠单个核细胞内游离钙浓度和白介素－1活性的变化

本文探讨了５／６肾切除术后慢性肾衰大鼠残肾纤维化的发生机理，发现术后１２０天，在残肾单个核炎性细胞浸润、残肾显著纤维化和肾功能损害的同时，残肾脂质过氧化物含量显著升高，抗氧化机制功能显著下降，钠钾ＡＴＰ酶活力显著下降，周围血单个核细胞内游离钙浓度显著升高，单个核细胞培养上清白介素－１活性增高。而摄入大量维生素Ｅ的大鼠，上述各指标有不同程度的改善，残肾纤维化显著减轻。提示残肾纤维化可能与单个核白细胞内游离钙浓度升高，进而产生白介素－１增多有关。     

Effects of motilin on intracellular free calcium in cultured smooth muscle cells from the antrum of neonatal rats

Aim: The aim of this study was to determine the effects of motilin on [Ca²⁺]_i regulation and its underlying molecular mechanism in cultured antral smooth muscle cells (ASMCs). Methods: Antral cells were isolated and cultured from neonatal rats, and then the [Ca²⁺]_i in these cells was evaluated by calcium fluorescent probe Fluo-3/AM on a laser scanning confocal microscope. Results: We show that motilin dose-dependently increased [Ca²⁺]_i concentration in cultured ASMCs. Pre-incubation of cells with either the calcium antagonist verapamil (10⁻⁵ mol L⁻¹) or the calcium chelator Egtazic (EGTA, 0.1 mmol L⁻¹) significantly suppressed motilin (10⁻⁶ mol L⁻¹) induced [Ca²⁺]_i increase as indicated by fluorescent intensity. Interestingly, after mixing with the non-selective intracellular calcium release blocker TMB-8 (10⁻⁵ mol L⁻¹), guanosine triphosphate regulatory protein antagonist NEM (10⁻⁵ mol L⁻¹), phospholipase C (PLC) inhibitor compound 48/80 (1.2 μg mL⁻¹) and ryanodine at high concentration (10⁻⁵ mol L⁻¹), the motilin-induced [Ca²⁺]_i increase was only partially blocked. The protein kinase C inhibitor d -sphingosine (10⁻⁶ mol L⁻¹), however, did not show any inhibitory effect on motilin-induced [Ca²⁺]_i elevation. Conclusions: Our study suggests that motilin-stimulated [Ca²⁺]_i elevation in ASMCs is probably due to sustained extracellular Ca²⁺ influx and Ca²⁺ release from Ca²⁺ stores via inositol tris-phosphate receptors and ryanodine receptors. Specifically, motilin-induced [Ca²⁺]_i release is accompanied with guanosine triphosphate-binding protein-coupled receptor–PLC–inositol tris-phosphate signalling cascades.