Login I S, Judd A M, Cronin M J, Yasumoto T, MacLeod R M
Am J Physiol. 1985 Jan;248(1 Pt 1):E15-9. doi: 10.1152/ajpendo.1985.248.1.E15.
Reserpine exerts direct effects on several tissues, including inhibition of hormone release from rat anterior pituitary cells. To test the hypothesis that reserpine may be acting as a calcium channel antagonist, normal or GH3 rat anterior pituitary cells were preincubated in reserpine or the conventional calcium channel blocker, D-600, followed by exposure to 45Ca2+ together with stimulants of calcium uptake: maitotoxin, a potent calcium channel activator; A23187, a calcium ionophore; or 50 mMK+. After incubation, the cells were harvested by vacuum filtration and cell-associated radioactivity determined. In normal cells, reserpine blocked both basal and K+-stimulated calcium uptake. Reserpine selectively blocked maitotoxin but not A23187-induced calcium uptake. In GH3 cells 9 microM reserpine and 30 microM D-600 were equally effective in blocking maitotoxin-stimulated calcium uptake. Reserpine appears to block voltage-dependent calcium channels in pituitary cells in a concentration-dependent manner but not calcium uptake caused nonspecifically by A23187.
利血平对多种组织有直接作用，包括抑制大鼠垂体前叶细胞释放激素。为了验证利血平可能作为钙通道拮抗剂起作用这一假说，将正常或GH3大鼠垂体前叶细胞预先在利血平或传统钙通道阻滞剂D - 600中孵育，然后与钙摄取刺激剂一起暴露于45Ca2 + ：巨大戟醇毒素，一种有效的钙通道激活剂；A23187，一种钙离子载体；或50 mM K + 。孵育后，通过真空过滤收获细胞并测定细胞相关放射性。在正常细胞中，利血平阻断基础和K + 刺激的钙摄取。利血平选择性地阻断巨大戟醇毒素诱导的钙摄取，但不阻断A23187诱导的钙摄取。在GH3细胞中，9 microM利血平和30 microM D - 600在阻断巨大戟醇毒素刺激的钙摄取方面同样有效。利血平似乎以浓度依赖性方式阻断垂体细胞中的电压依赖性钙通道，但不阻断由A23187非特异性引起的钙摄取。
