Block of calcium channels by enkephalin and somatostatin in neuroblastoma-glioma hybrid NG108-15 cells.
Block of calcium channels by enkephalin and somatostatin in neuroblastoma-glioma hybrid NG108-15 cells.
复制标题
神经母细胞瘤-神经胶质瘤杂交 NG108-15 细胞中脑啡肽和生长抑素阻断钙通道。
DOI：
10.1073/pnas.83.24.9832
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发表时间：
1986
影响因子：
11.1
通讯作者：
Narahashi,T
中科院分区：
文献类型：
--
作者：
Tsunoo,A;Yoshii,M;Narahashi,T
亮氨酸-脑啡肽、甲硫氨酸-脑啡肽和吗啡可可逆性阻断神经母细胞瘤-胶质瘤杂交细胞（NG 108 -15）的钙通道电流。亮氨酸脑啡肽阻断了Ca 2+通道电流的长期（2型）成分，而瞬时（1型）成分不受影响。脑啡肽诱导的阻断作用被纳洛酮拮抗，似乎是由δ-阿片受体介导的。两个不同的方面的封锁效果进行了检测，休息块和恢复从块在延长去极化脉冲。从阻滞中恢复更完全，其时间进程更快，去极化更积极的电位。2型通道阻滞剂在静息状态下的剂量依赖性表明一对一结合化学计量，表观解离常数为8.8 nM。生长抑素对2型Ca ~（2+）通道也有类似的选择性阻断作用。2型钙通道的时间和电压依赖性阻滞可能提供了脑啡肽能突触前抑制递质释放和生长抑素阻滞垂体生长激素释放的机制。
Leucine-enkephalin, methionine-enkephalin, and morphine caused a reversible block of Ca2+ channel currents in neuroblastoma-glioma hybrid cells (NG108-15). The long-lasting (type 2) component of the Ca2+ channel current was blocked by leucine-enkephalin, while the transient (type 1) component was not affected. The enkephalin-induced blocking action was antagonized by naloxone and appears to be mediated by delta-opiate receptors. Two different aspects of the blocking effect were detected, a resting block and a recovery from block during prolonged depolarizing pulses. Recovery from block was more complete, and its time course was more rapid, with depolarization to more positive potentials. The dose dependence of the type 2 channel block at rest indicated a one-to-one binding stoichiometry, with an apparent dissociation constant of 8.8 nM. Somatostatin exerted a similar selective blocking action on the type 2 Ca2+ channel. The time- and voltage-dependent block of type 2 Ca2+ channels may provide a mechanism underlying the enkephalinergic presynaptic inhibition of transmitter release and the somatostatin block of pituitary growth hormone release.