Pentazocine Inhibits Norepinephrine Transporter Function by Reducing its Surface Expression in Bovine Adrenal Medullary Cells
Pentazocine Inhibits Norepinephrine Transporter Function by Reducing its Surface Expression in Bovine Adrenal Medullary Cells
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DOI：
10.1254/jphs.12164fp
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发表时间：
2013-02-01
影响因子：
3.5
通讯作者：
Yanagihara, Nobuyuki
中科院分区：
文献类型：
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作者：
Obara, Go;Toyohira, Yumiko;Yanagihara, Nobuyuki
(+/-)-五唑碱(PTZ)是一种非麻醉性止痛剂，用于临床治疗中度至重度疼痛。为了研究PTZ对去甲肾上腺素能下行抑制系统的影响，本研究观察了体外培养的牛肾上腺髓质细胞和人神经母细胞瘤SK-N-SH细胞摄取去甲肾上腺素(NE)的作用。(-)-PTZ和(+)-PTZ抑制肾上腺髓质细胞摄取[H-3]NE的作用呈浓度依赖性(3-100mU/M)。Eadie-Hofstee对[H-3]NE摄取的分析表明，两种PTZ均导致V-max显著降低，而表观K-m变化不大，提示非竞争性抑制。Kappa阿片和Sigma受体拮抗剂Nor-Binaltorphimine和BD-1047分别不影响(-)-PTZ和(+)-PTZ对[H-3]NE摄取的抑制作用。PTZ抑制[H-3]Nisoxetine与完整SK-N-SH细胞的特异性结合，但不直接与牛肾上腺髓质分离的质膜结合。[H-3]尼索西汀与SK-N-SH细胞结合的Scatchard分析表明，PTZ降低了Bmax而不改变表观K-d。Western印迹分析显示，经(-)-PTZ处理后，生物素化的细胞表面NE转运体(NET)的表达减少。这些发现表明，PTZ通过阿片和西格玛受体非依赖的途径减少细胞表膜上的Net数量，从而抑制Net的功能。
(+/-)-Pentazocine (PTZ), a non-narcotic analgesic, is used for the clinical management of moderate to severe pain. To study the effect of PTZ on the descending noradrenergic inhibitory system, in the present study we examined the effect of [H-3]norepinephrine (NE) uptake by cultured bovine adrenal medullary cells and human neuroblastoma SK-N-SH cells. (-)-PTZ and (+)-PTZ inhibited [H-3]NE uptake by adrenal medullary cells in a concentration-dependent (3 - 100 mu M) manner. Eadie-Hofstee analysis of [H-3]NE uptake showed that both PTZs caused a significant decrease in the V-max with little change in the apparent K-m, suggesting non-competitive inhibition. Nor-Binaltorphimine and BD-1047, kappa-opioid and sigma-receptor antagonists, respectively, did not affect the inhibition of [H-3]NE uptake induced by (-)-PTZ and (+)-PTZ, respectively. PTZs suppressed specific [H-3]nisoxetine binding to intact SK-N-SH cells, but not directly to the plasma membranes isolated from the bovine adrenal medulla. Scatchard analysis of [H-3]nisoxetine binding to SK-N-SH cells revealed that PTZs reduced the B-max without changing the apparent K-d. Western blot analysis showed a decrease in biotinylated cell-surface NE transporter (NET) expression after the treatment with (-)-PTZ. These findings suggest that PTZ inhibits the NET function by reducing the amount of NET in the cell surface membranes through an opioid and sigma-receptor-independent pathway.