维拉帕米A_(23187)对成纤维细胞胶原基因表达的影响

研究维拉帕米（Ver）和A23187对3T6成纤维细胞Ⅲ、Ⅳ型胶原基因表达的影响，旨在探讨Ca2+对胶原合成的作用。实验采用标记Ⅲ、Ⅳ型前胶原cDNA探针与RNA斑点印迹的杂交，检测了Ver、23187，对Ⅲ、Ⅳ型前胶原mRNA水平的影响。结果显示，Ver、A23187不同程度的降低了Ⅲ、Ⅳ型前胶原mRNA的水平。表明Ca2+参与了胶原合成的调控。

内、外源性生长抑素对离体培养的胰岛β细胞抗链佐霉素损伤的保护作用

在以前整体及器官水平工作的基础上,本工作进一步在离体培养的胰岛细胞上观察生长抑素(somatostatin,SS)对链佐霉素(streptozotocin,STZ)诱导的胰岛β细胞损伤的保护作用。结果表明,在向培养的胰岛细胞中加入STZ前10min,加入不同剂量(0.025,0.05和0.1μg/ml)的SS,可不同程度地保护β细胞免受STZ的破坏。给药后6h,活细胞数由STZ破坏组的41.13±0.65万个/ml分别回升到49.0±2.0,53.0±1.33和53.38±1.74万个/ml;在给药后12h,活细胞数由破坏组的46.75±0.75万个/ml,分别升为53.0±1.25,57.04±2.39和63.13±0.62万个/ml,与破坏组间均有显著差异。电镜下超微结构的观察显示,破坏组胰岛内β细胞大量死亡,胞质内正常细胞器结构消失,代之以大量空泡和颗粒状物质;胞核结构不清。而保护组的β细胞结构完整,分泌颗粒轮廓典型,高尔基复合体及线粒体结构正常。用SS抗血清中和内源性SS后再给予STZ,β细胞破坏更为严重,但重新补充SS则可翻转抗血清的效果。加入钙离子载体A_(23187),对SS的保护作用无明显影响,表明这一作用可能与Ca^(2+)机制无关。

Correlation between inhibition of calcium-dependent apoptosis by cyclosporin A and calcium transportation in HL-60 cells

Both calcium ionophore A23187 and endoplasmic reticulum Ca2+- ATPase inhibitor thapsigargin (Tg) could increase intracellular free calcium concentration and induce apoptosis in some cell lines. In the present study, we found that HL-60 cells treated with A23187 (1μg/ml) for 4 h or with Tg (0.5μg/ml) for 2 h showed typical characteristics of apoptosis. Pretreatment with nontoxic concentration of cyclosporin A (CsA) (1μg/ml) Could block these effects. Flow cytometric analysis of intracellular Ca2+ after staining with fluo-3 AM showed that CsA did not prevent the increase of intracellular calcium induced by A23187 or Tg, but it could maintain the high level of intracellular Ca2+ for a long time. These results suggest that CsA may prevent calcium- induced apoptosis by blocking the transportation of Ca2+ in HL-60cells.