Quantal size of catecholamine release from rat chromaffin cells is regulated by tonic activity of protein kinase A
Quantal size of catecholamine release from rat chromaffin cells is regulated by tonic activity of protein kinase A
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DOI：
10.1016/j.neulet.2004.02.057
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发表时间：
2004-04
影响因子：
2.5
通讯作者：
Takeshi Koga;Masami Takahashi
中科院分区：
文献类型：
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作者：
Takeshi Koga;Masami Takahashi
为了阐明蛋白激酶A （PKA）的滋补活性在胞外分泌调节中的作用，我们研究了在缺乏PKA激活剂的情况下，选择性PKA抑制剂对大鼠嗜铬细胞释放儿茶酚胺（CA）的影响。肉豆蔻酰基化蛋白激酶抑制剂（myr-PKI）降低单个细胞CA释放总量，而H-89对CA释放总量和频率没有影响。安培记录显示，myr-PKI对每个细胞的安培峰值数量只有很小的影响，但优先抑制大量子大小的胞外事件。定量大小分布的变化与细胞CA含量的减少无关，用HPLC定量。这些结果表明，细胞膜附近PKA的强直活性通过调节量子大小来调节神经递质释放。
To address the roles of tonic activity of protein kinase A (PKA) in the regulation of exocytosis, we examined the effects of selective PKA inhibitors on catecholamine (CA) release from rat chromaffin cells in the absence of PKA activators. Myristoylated protein kinase inhibitor (myr-PKI) reduced the total amount of CA released from a single cell, whereas H-89 did not affect the total amount and frequency of CA release. Amperometric recording revealed that myr-PKI had only a small effect on the number of amperometric spikes per cell, but preferentially inhibited exocytotic events of large quantal size. The change in quantal size distribution was not associated with a reduction of cellular CA content, quantified by using HPLC. These results suggest that the tonic activity of PKA near the cell membrane regulates neurotransmitter release by modulating quantal size.