FORSKOLIN EFFECTS ON GLIAL AND CEREBROMICROVASCULAR CULTURES

环核苷酸在生长控制和分化中的作用尚不清楚。 悬而未决。福斯可林，一种可以直接 刺激腺苷酸环化酶的催化亚单位，允许研究 CAMP对脑细胞生长调控的新视角。神经胶质 取脑微血管内皮细胞、血管内皮细胞和平滑肌细胞。 用于这项体外研究。CAMP产生，胸腺嘧啶核苷掺入， 并观察细胞形态和细胞骨架的变化。 结果表明，在所有三种细胞类型中，胸腺嘧啶核苷 掺入呈剂量依赖性减少，并最大限度地抑制生长 在100毫米福斯柯林。取消了与Forsklin的一小时预孵化 含胎牛血清(FCS)培养液中胸腺嘧啶核苷的掺入 接下来的24小时。接触Forsklin也会导致剧烈和 内皮细胞形态和F-肌动蛋白组成的即刻变化 和光滑的肌肉。这些变化是可逆的。在胶质细胞中 只有在接触Forsklin更多时间后，才能看到形态变化 而不是24小时。这些变化伴随着染色增加。 抗胶质纤维酸性蛋白抗体。 这些发现支持cAMP在这些细胞的生长调节中的作用 表明Forskolin可能被用作诱导生长停滞和 最终在哺乳动物大脑的细胞培养中分化。

The role of cyclic nucleotides in growth control and differentiation is yet unresolved. The recent availability of forskolin, a drug which directly stimulates the catalytic subunit of adenylate cyclase, allowed to study growth regulation of brain cells by cAMP from a new viewpoint. Glial cells, endothelium and smooth muscle cells from brain microvessels were used for this in-vitro study. cAMP production, thymidine incorporation, and morphological and cytoskeletal changes were examined. The results demonstrated that in all three cell types, thymidine incorporation was reduced dose-dependently with maximal growth inhibition at 100 MuM forskolin. A one hour preincubation with forskolin abolished thymidine incorporation in fetal calf serum (FCS)-containing medium over the following 24 hours. Exposure to forskolin led also to drastic and immediate changes of cell morphology and F-actin composition in endothelium and smooth muscle. These changes were reversible. In glial cells morphologic changes were visible only after exposure to forskolin for more than 24 hours. These changes were accompanied by increased staining with antibodies against glial fibrillary acidic protein. The findings support a role of cAMP in growth regulation of these cells and indicate that forskolin might be used as a tool to induce growth arrest and eventually differentiation in cell cultures from mammalian brain.