Sánchez-Olea R, Morales Mulia M, Morán J, Pasantes-Morales H
Institute of Cell Physiology, National University of Mexico, Mexico City.
Neurosci Lett. 1995 Jul 7;193(3):165-8. doi: 10.1016/0304-3940(95)11691-o.
The 1,4-dihydropyridines (DHP), nimodipine (NMD) and nitrendipine (NTD) were potent blockers of regulatory volume decrease (RVD) and the volume-associated release of [3H]taurine and chloride (measured as 125I) in 2-weeks cultured rat cerebellar astrocytes. The IC50 were 30 microM and 29 microM for taurine efflux and 26 and 27 microM for C1 efflux for NMD and NTD, respectively. Inhibition by DHP was independent of extracellular Ca, as the effect was the same in media with 1 mM Ca or without Ca and 0.5 mM EGTA. DHP did not affect the basal (isosmotic) release of [3H]taurine or 125I inhibition by DHP (measured only on [3H]taurine efflux) was the same in 3-4 weeks cultured cerebellar astrocytes, 2-4 weeks cultured cortical astrocytes and 2-weeks cultured cerebellar astrocytes treated with dibutyril cAMP. Diltiazem (50 microM) and verapamil (100 microM) failed to inhibit RVD or osmolyte efflux.
1,4 - 二氢吡啶类化合物(DHP)、尼莫地平(NMD)和尼群地平(NTD)是培养2周的大鼠小脑星形胶质细胞中调节性容积减小(RVD)以及与容积相关的[3H]牛磺酸和氯离子(以125I测量)释放的强效阻滞剂。尼莫地平和尼群地平对牛磺酸外排的IC50分别为30 microM和29 microM,对氯离子外排的IC50分别为26 microM和27 microM。DHP的抑制作用不依赖于细胞外钙,因为在含有1 mM钙或不含钙及0.5 mM乙二醇双四乙酸(EGTA)的培养基中效果相同。DHP不影响[3H]牛磺酸的基础(等渗)释放,且在培养3 - 4周的小脑星形胶质细胞、培养2 - 4周的皮质星形胶质细胞以及用二丁酰环磷腺苷(cAMP)处理培养2周的小脑星形胶质细胞中,DHP对[3H]牛磺酸外排的抑制作用(仅针对[3H]牛磺酸外排测量)相同。地尔硫䓬(50 microM)和维拉帕米(100 microM)未能抑制RVD或渗透溶质外排。