Inhibitory effects of melatonin on free intracellular calcium in mouse brain cells

目的：研究褪黑激素（Ｍｅｌ）对老年小鼠大脑皮层突触体内钙含量以及激动剂诱发的新生小鼠脑细胞［Ｃａ２＋］ｉ升高的影响,以探讨Ｍｅｌ抗衰老的作用机理．方法：钙离子荧光染料Ｆｕｒａ２ＡＭ负载已制备的突触体或细胞,用ＲＦ５０００型双波长荧光分光光度计测定［Ｃａ２＋］ｉ．结果：长期使用Ｍｅｌ抑制老年小鼠大脑皮层Ｃａ２＋超负荷,Ｍｅｌ也降低钙通道激活剂ＢａｙＫ８６４４,高浓度氯化钾（ＫＣｌ）和谷氨酸钠诱发的分离的新生小鼠脑细胞［Ｃａ２＋］ｉ升高．结论：Ｍｅｌ对中枢神经元［Ｃａ２＋］ｉ超载的抑制作用与其抗衰老作用有关．     

维拉帕米对大鼠脑突触体内Ca^2＋和Ca^（2＋）Mg^（2＋）—ATP酶的影响

维拉帕米１０，５０和１００μｍｏｌ．Ｌ＾－１能增加高Ｋ＾＋和去甲肾上腺素所致大鼠脑突触体内激离Ｃａ＾２＋的浓度，但使静息状态突触体内游离Ｃａ＾２＋浓度下降。Ｖｅｒ还抑制突触体Ｃａ＾（２＋）Ｍｇ＾（２＋）－ＡＴＰ酶活性。结果提示：与静息状态不同，在神经末梢受到刺激时，Ｖｅｒ可能是通过抑制ＣａＭ，进而抑制Ｃａ＾（２＋）Ｍｇ＾（２＋）－ＡＴＰ酶活性，使胞浆内游离Ｃａ＾（２＋）升高，引起递质释放量增加。     

卡托普利和依那普利拉对分离的大鼠心肌细胞内游离Ca^2＋浓度的影响

目的：研究转换酶抑制剂卡托普利（Ｃａｐ）和依那普利拉（Ｅｎａ）对ＳＨＲ和ＷＫＹ大鼠心肌细胞内游离Ｃａ＾２＋浓度的影响，方法：用荧光探针Ｆｕｒａ２－ＡＭ结合计算机图象处理技术测定分离心肌细胞内游离Ｃａ＾２＋浓度，结果：ＳＨＲ心理细胞内游离Ｃａ＾２＋浓度（１７４±５ｎｍｏｌ．Ｌ＾－１）较ＷＫＹ大鼠（１４８±１５ｎｍｏｌ．Ｌ＾－１）高（Ｐ〈０．０１），Ｃａｐ和Ｅｎａ能明显降低ＳＨＲ心肌细胞内游离Ｃａ＾２     

尼莫地平,非洛地平和维拉帕米对离体人血管作用

观察尼莫地平（Ｎｉｍ）非洛地平（Ｆｅｌ）是否有不同的作用模式。方法：比较尼莫地平（Ｎｉｍ），非洛地平（Ｆｅｌ）对去甲肾上腺素（ＮＥ）和氯化ＣａＣｌ２引起的人动脉收缩的不同作用，并且与维拉帕米（Ｖｅｒ）的作用相比较。结果：Ｎｉｍ，Ｆｅｌ对无Ｃａ＾２＾＋ｙｍ Ｋ＾＋去极化时ＣａＣｌ２所致离体人血管收缩的拮抗作起收缩时，Ｎｉｍ，Ｆｅｌ和Ｖｅｒ拮抗作用ｐＤ２在子宫动脉分别为７．３８，７．６５和７．２０；在     

地塞米松对新生小鼠海马和培养的皮层神经胶质中敏感细胞内钙浓度的影响

目的：研究地塞米松（Ｄｅｘ）对神经元和胶质细胞内钙浓度（Ｃａ＾２＋）ｉ的影响,方法：Ｆｕｒａ２－ＡＭ负载小鼠海马细胞（ＮＭＨＣ）和培养的胶质细胞（ＣＣＮ）,单细胞内（Ｃａ＾２＋）ｉ由ＡＲ－ＣＭ－ＭＩＣ检测系统测定。结果：Ｄｅｘ使多数ＮＭＨＣ（Ｃａ＾２＋）ｉ浓度依赖地迅速升高,９６个ＮＭＨＣ中公１０％出现（Ｃａ＾２＋）ｉ降低,（Ｃａ＾２＋）ｉ,升高被无镁细胞外液阻滞,被氯化镧逆转,但不受氯化锂影响,     

受精和人工激活诱导的小鼠卵内游离钙离子变化

目的：研究哺乳类动物卵母细胞激活机制，方法：将休止于第二次成熟分裂中期的小鼠卵母细胞负载Ｆｕｒａ２－ＡＭ后用乙醇，钙离子载体，电脉冲或受精等激活，采用ＳｐｅｘＡＲ－ＣＭ－ＭＩＣ阳离子检测系统测定卵激活过程中细胞内游离Ｃａ＾２＋浓度变化；电镜下检测卵激活后皮质颗粒释放，结果在含Ｃａ＾２＋（１．７ｍｍｏｌ．Ｌ＾－１）的ＩＶＦ液中，精子受精诱发卵内Ｃａ＾２＋浓度波动，这种Ｃａ＾２＋波动持续达３－４ｈ直到     

三氟拉嗪对大鼠脑突触体内Ca2＋水平和Ca2＋，Mg2＋─ATP酶活性的作用

用Ｑｕｉｎ２法测得大鼠脑突触体内静息游离Ｃａ２＋浓度（［Ｃａ２＋］ｉ）为８５±１３μｍｏｌ·ｇ－１ｐｒｏｔｅｉｎ．三氟拉嗪（ＴＦＰ）１，５和１０μｍｏｌ·Ｌ－１对静息突触体［Ｃａ２＋］ｉ无明显影响，但能以剂量依赖方式增高６５ｍｍｏｌ·Ｌ－１ＫＣｌ所致突触体［Ｃａ２＋］ｉ升高，从１９２±５８μｍｏｌ·ｇ－１ｐｒｏｔｅｉｎ分别达到２３３±６３，４３１±９９和６６１±１７３μｍｏｌ·ｇ－１ｐｒｏｔｅｉｎ．ＴＦＰ５，１０和５０μｍｏｌ·Ｌ－１分别使突触体Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶活性降低３１％，４１％和４５％；使Ｍｇ２＋－ＡＴＰ酶活性降低３０％，３６％和３９％，提示ＴＦＰ可能是通过抑制钙调素，进而抑制Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶活性，使突触体［Ｃａ２＋］ｉ升高，促进神经末梢释放递质     

钾通道开放剂降低血管平滑肌细胞内游离钙浓度

研究ＰＣＯ－Ｐｉｎ，Ｎｉｃ，Ｌｅｍ及ＲＰ对ＶＭＳＣ内［Ｃａ＾２＋］ｉ的改变及其可能机制。ＶＳＭＣ加入Ｆｕｒａ－２ＡＭ２．５μｍｏｌ．Ｌ＾－１３７℃下孵育５０ｍｉｎ，［Ｃａ＾２＋］ｉ用荧光分光光度计检测。４种ＰＣＯ能较弱地抑制Ｋ＾＋３０ｍｍｏｌ．Ｌ＾－１诱导的［Ｃａ＾２＋］ｉ增加，但明显抑制ＡＴＰ０．１ｍｍｏｌ．Ｌ＾－１诱导的［Ｃａ＾２＋］ｉ峰相及持续相增加，且呈剂量依赖性。格列苯脲完全阻断Ｐｉｎ，     

蜂毒肽Mastoparan诱导大鼠小脑颗粒神经元死亡的机制

目的 研究蜂毒肽ｍａｓｔｏｐａｒａｎ（ＭＰ）通过改变细胞内钙离子浓度（［Ｃａ＾２＋］ｉ）诱导大鼠小脑颗粒神经元死亡的机制。方法 测定原代培养神经元的存活率；用Ｆｕｒａ－２／ＡＭ荧光比值成像技术测定［Ｃａ＾２＋］ｉ。结果 ＭＰ剂量依赖性地诱导小脑颗粒神经元死亡，并触发［Ｃａ＾２＋］ｉ升高。移去细胞外钙，或使用电压依赖性Ｃａ＾２＋通道阻滞剂尼莫地平不能阻断其作用。用ｔｈａｐｓｉｇａｒｇｉｎ预先耗竭１，     

甲基黄酮醇胺对分离的胎鼠脑细胞内游离钙浓度的影响

目的：观察甲基黄酮醇胺（ＭＦＡ）对胎鼠脑细胞内游离钙浓度在静息以及激动剂存在时的作用。方法：用钙离子荧光染料Ｆｕｒａ２－ＡＭ负载后，测定分离的胎鼠脑细胞内游离钙浓度（Ｃａ＾２＋）及其变化。结果：在含钙１．３ｍｍｏｌ．Ｌ＾－１的Ｈａｎｋｓ’液中，（Ｃａ＾２＋）为１９７±２０ｎｍｏｌ．Ｌ＾－１（ｎ＝４４），ＭＦＡ０．１５ｍｍｏｌ．Ｌ＾－１对静息脑细胞内钙浓度无明显影响。在细胞外钙１．３ｍｍｏｌ．Ｌ＾－     

前胡丙素对高血压大鼠血管肥厚、细胞内钙、胶原及NO的影响

目的　研究前胡丙素对自发性高血压大鼠SHR及肾型高血压大鼠RHR的血管肥厚、细胞内钙、胶原、NO及血管收缩的反应性影响。方法用显微测微仪测定血管中膜层厚度,细胞大小,用Fura-2/AM为荧光指示剂,测定单细胞内［Ca²⁺］i,以测定羟脯氨酸含量反映胶原含量,用Griess法测定NO含量,以血管环观察收缩反应。结果　前胡丙素抑制血管中膜层增厚,维持细胞内［Ca²⁺］i稳态。减少胶原形成,增加SMCs释放NO。抑制血管环高反应状态。结论　前胡丙素抑制高血压血管肥厚,降低胶原含量及血管异常反应。     

小檗碱对培养大鼠神经细胞内游离Ca^2＋的影响

以Ｆｕｒａ２／ＡＭ为细胞内钙离子的荧光指示剂，用ＡＲＣＭＭＩＣ阳离子测定系统，直接测定了体外培养的新生大鼠神经细胞内游离钙（［Ｃａ２＋］ｉ）值，并观察了小檗碱（Ｂｅｒ）的影响。结果表明，Ｂｅｒ对神经细胞静息［Ｃａ２＋］ｉ无明显影响，Ｂｅｒ１～１００μｍｏｌ·Ｌ－１能剂量依赖地抑制去甲肾上腺素和Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ升高，其ＩＣ５０分别为３９．９和１７．９μｍｏｌ·Ｌ－１。高剂量Ｂｅｒ（１０～１００μｍｏｌ·Ｌ－１）能抑制高Ｋ＋引起的［Ｃａ２＋］ｉ升高。姐果提示，Ｂｅｒ对去甲肾上腺素，高Ｋ＋及Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ升高的抑制作用可能是其抗脑缺血作用机制之一。     

褪黑激素对大脑皮层谷氨酸释放及其神经毒的拮抗作用

AIM: To observe the effects of melatonin (Mel) on glutamate (Glu) release from the cortical synaptosomes in old mice and on neurotoxicity induced by KCl, Glu in cultured cortical cells of fetal rat and to explore the antiaging mechanism of Mel. METHODS: Glu release by the synaptosomes in old mouse cerebral cortex was detected in a spectrofluorophotometer. The neuronal viability in primary cultures from rat cerebral cortex was assessed using MTT stain and lactate dehydrogenase (LDH) efflux in the bathing medium. RESULTS: Mel inhibited the K+ (30 mmol.L-1)-induced Glu release from synaptosomes either in calcium dependent or independent conditions [control (10.6 +/- 1.1), (9.2 +/- 0.7) mumol.g-1 (protein); Mel 0.1 mumol.L-1 (6.5 +/- 0.9), (7.5 +/- 0.6) mumol.g-1 (protein), respectively, P < 0.01 vs control group), increased MTT activity (control 0.67 +/- 0.04, 0.81 +/- 0.03; Mel 0.1 mumol.L-1 0.715 +/- 0.023, 0.925 +/- 0.027, P < 0.01 vs control group] and decreased LDH efflux (control 0.400 +/- 0.016, 0.379 +/- 0.016; Mel 0.1 mumol.L-1 0.345 +/- 0.021, 0.340 +/- 0.012, respectively, P < 0.01 vs control group), therefore, protected the neuronal viability against KCl and Glu-induced injury. CONCLUSION: The inhibitory effect of Mel on Glu release from cortical synaptosome and the protective effect of Mel on cortical neurons against neurotoxicity are its antiaging mechanisms.     

卡托普利对缺氧诱导的肺动脉平滑肌细胞增殖和胶的合成的抑制作用

AIM: To study the effect of captopril (Cap) on hypoxia-induced proliferation and collagen synthesis in vascular smooth muscle cells (VSMC). METHODS: VSMC were isolated from rabbit pulmonary artery. Cultured VSMC were evaluated by incorporation of [3H]thymidine and [3H]proline, cell number, and intracellular calcium concentration ([Ca2+]i). RESULTS: Pretreatment of pulmonary VSMC with Cap 1 mumol.L-1 blocked hypoxia-induced increase in cell number and incorporation of [3H]proline and [3H]thymidine, which were decreased 25%, 21%, and 36%, respectively, as compared with hypoxic control. It also inhibited the increase of intracellular Ca2+ concentration under hypoxic condition. Addition of nifedipine inhibited hypoxia-stimulated increase in the collagen, DNA synthesis, and [Ca2+]i. Bay-K-8644 increased cell number (35%), DNA (55%), collagen synthesis (36%), and [Ca2+]i (33%) in pulmonary VSMC, that was completely abolished by Cap 1 mumol.L-1. CONCLUSION: Cap inhibited hypoxia-induced proliferation and collagen synthesis in VSMC.     

小檗胺对高钾,去甲肾上腺素及咖啡因引起大鼠心肌细胞内钙动拮？…

AIM: To study the effects of berbamine (Ber) on intracellular calcium concentration ([Ca2+]i) mobilized by KCl depolarization, norepinephrine (NE), and caffeine. METHODS: [Ca2+]i was measured with fluorescent intensity (FI) by confocal microscope in single cultured cardiomyocytes of newborn rats loaded with Fluo 3-AM 2 mumol.L-1. RESULTS: FI value of [Ca2+]i in control level was 248 +/- 70 in the presence of extracellular calcium 1.5 mmol.L-1 and was not changed by Ber 3-30 mumol.L-1. KCl (60 mmol.L-1)- and NE (30 mumol.L-1)-induced [Ca2+]i mobilizations were inhibited (P < 0.01) by Ber 30 mumol.L-1, similar to that of verapamil (Ver). The inhibitory effect of Ber on [Ca2+]i induced by KCl was further increased (P < 0.05) in the presence of egtazic acid 3 mmol.L-1, but that on [Ca2+]i induced by NE was not changed. The [Ca2+]i mobilized by caffeine 80 and 160 mumol.L-1 in D-Hanks' solution was not affected (P > 0.05) by Ber and Ver. CONCLUSION: Ber possessed the antagonistic effects on [Ca2+]i increases via voltage-dependent Ca2+ channel and receptor-operated Ca2+ channel in newborn rat cardiomyocytes, but without effect on intracellular Ca2+ release.     

金丝桃苷对分离的新生大鼠脑细胞内游离钙浓度的影响

AIM: To study the effects of hyperin (Hyp) on free intracellular calcium concentration ([Ca2+]i) of brain cells. METHODS: The neonatal rat brain cells were dissociated. [Ca2+]i in presence and absence of extracellular high K+, L-glutamic acid (Glu), 5-hydroxytryptamine (5-HT), and norepinephrine (NE) were assayed with Fura 2-AM. RESULTS: The resting [Ca2+]i in Hanks' solution (CaCl2 1.3 mmol.L-1) was (208 +/- 12) nmol.L-1 (n = 17). Hyp had no significant effects on the resting [Ca2+]i. Hyp 1.0, 4.0, and 16.0 mumol.L-1 markedly inhibited the increase of [Ca2+]i evoked by K+ 50 mmol.L-1 in a concentration-dependent manner. Hyp 16.0 mumol.L-1 inhibited the increases of [Ca2+]i induced by NE 1, 2, 4, and 8 mumol.L-1. Hyp (16.0 mumol.L-1) also markedly attenuated 5-HT and Glu-induced increase of [Ca2+]i. CONCLUSION: Hyp possessed inhibitory effects on influx of Ca2+ in the neonatal rat brain cells.     

小檗胺对培养的HeLa细胞内游离钙浓度的作用

AIM: To study the involvement of Ca2+ signaling and the effects of berbamine (Ber) on intracellular calcium concentration ([Ca2+]i) elevated in cultured HeLa cells. METHODS: [Ca2+]i was measured by confocal microscopy in single HeLa cell loaded with Fluo 3-AM. The change of [Ca2+]i was represented by fluorescent intensity (FI). RESULTS: (1) In the presence of extracellular Ca2+ 1.3 mmol.L-1, the resting level of FI was 186 +/- 44, n = 49 cells from all control experiments, and KCl, NE, caffeine, and calcimycin (Cal) all induced [Ca2+]i elevations in cultured HeLa cells. (2) The resting level of FI was not affected by pretreatment with Ber. The FI increased by KCl 60 mmol.L-1, NE 100 micromol.L-1, and Cal 30 micromol.L-1 were attenuated (P < 0.05 or P < 0.01), the slope and the time to peak of FI increase were decreased and prolonged. (3) In the absence of extracellular Ca2+, caffeine 80 mmol.L-1-induced [Ca2+]i mobilization was not inhibited by Ber 100 micromol.L-1 pretreatment. (4) These effects of Ber were similar to those of verapamil (Ver) 10 mumol.L-1. CONCLUSION: Although it was derived from cervical cancer, the HeLa cells which were belong to the nonexcitable cell possessed the similar biological properties with excitable cells, and Ca2+ also played a crucial role in signal transduction processes.