1,25-DIHYDROXYVITAMIN-D3 STIMULATES CA-45(2+)-UPTAKE BY CULTURED VASCULAR SMOOTH-MUSCLE CELLS DERIVED FROM RAT AORTA
1,25-DIHYDROXYVITAMIN-D3 STIMULATES CA-45(2+)-UPTAKE BY CULTURED VASCULAR SMOOTH-MUSCLE CELLS DERIVED FROM RAT AORTA
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DOI：
10.1016/s0006-291x(88)80439-x
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发表时间：
1988-05-16
影响因子：
3.1
通讯作者：
KAWASHIMA, H
中科院分区：
文献类型：
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作者：
INOUE, T;KAWASHIMA, H
我们最近发现了1，25-二氢维生素D3受体的存在，并且1，25-二羟基维生素D3可能通过受体介导的机制刺激血管平滑肌细胞中的Ca-ATPase。这些数据表明，类固醇可能直接参与了细胞内钙稳态的调节。为了进一步确定维生素D在平滑肌细胞中的作用，我们研究了类固醇对细胞钙摄取的影响。1，25-二羟基维生素D3可促进培养的胎鼠主动脉A7r5细胞与甾醇孵育18小时后摄取45Ca~(2+)。这种效应在10-10到10-9M范围内呈剂量依赖关系，需要高三个数量级的25-羟基维生素D3或24，25-二羟基维生素D3浓度才能获得类似的效果。此外，1，25-二羟基维生素D3的作用可被蛋白质合成抑制剂放线菌酮(10-5M)所消除。这些数据清楚地表明，1，25-二羟基维生素D3可能通过受体介导的机制直接调节血管平滑肌细胞的钙稳态。
We have recently shown the presence of receptors for 1,25-dihyroxyvitamin D3 and that 1,25-dihydroxyvitamin D3 stimulates Ca-ATPase in vascular smooth muscle cells presumably via receptor mediated mechanism. These data suggest that the sterol may directly be involved in the regulation of cellular calcium homeostasis. To further define action of vitamin D in smooth muscle cells, we studied effects of the sterol on cellular uptake of calcium. 1,25-dihydroxyvitamin D3 stimulated 45Ca2+ uptake by cultured cells, A7r5, derived from fetal rat aorta, when the cells were incubated with the sterol for 18 hr. The effect was dose-dependent at 10-10 to 10-9 M, and three orders of magnitude higher concentration of 25-hydroxyvitamin D3 or 24,25-dihydroxyvitamin D3 was needed to obtain similar effects. Furthermore, the effect of 1,25-dihydroxyvitamin D3 was abolished by cycloheximide (10-5 M), a protein synthesis inhibitor. These data clearly suggest that 1,25-dihydroxyvitamin D3 may directly regulate cellular calcium homeostasis in vascular smooth muscle cells presumably via receptor mediated mechanism.