吗啡对人神经母细胞瘤SK—N—SH细胞L—Ca^2＋通道的作用

Effect of morphine on L - calcium channel of SK- N - SH human neuroblastoma cells

目的观察吗啡对人神经母细胞瘤SK-N—SH细胞L—Ca^2＋通道的影响。方法培养人神经母细胞瘤SK—N—SH细胞，应用细胞贴附式膜片钳技术记录在不同浓度吗啡（0.10^-8mol／L、10^-4mol／L、10^-6mol／L、10^-5mol／L）作用下SK—N—SH细胞L—Ca^2＋通道电流和电导变化。预先加入10^-5mol／L纳洛酮后，再依次加入上述不同浓度吗啡，记录此通道电流和电导。结果10^-7mol／L、10^-6mol／L、10^-5mol／L吗啡可抑制SK—N—SH细胞L-型Ca^2＋通道电流，吗啡浓度为10^-6mol／L、10^-5mol／L时抑制作用更明显（P〈0．01），具有浓度依赖性；各浓度吗啡对L—Ca^2＋通道电导无影响；预先加入纳络酮，可阻断吗啡对该通道的抑制作用。结论吗啡可抑制SK—N—SH细胞上L—Ca^2＋通道电流，对该通道电导无作用。纳络酮可翻转吗啡的作用，其抑制作用可能通过μ阿片受体产生。

Objective To study the effect of morphine on L - calcium channels of SK - N - SH human neuroblastoma cells. Methods SK - N - SH human neuroblastoma cells were cultured in vitro. Electrical current and conductance of calcium channels of SK - N - SH cells were measured using cell - attached patch clamp technique in the presence of morphine with different concentrations （0, 10^-8mol/L, 10^-7mo]/ L, 10^-6mol/ L and 10^-5mol/ L） preteated with or without naloxone （10^-5mol/L）. Results Electrical current of L - calcium channels of SK - N - SH human neuroblastoma cells was concentration - dependently depressed by morphine （ P 〈0, 01 at concentrations of 10^-7, 10^-6 and 10^-5 mo//L）. Pretreatment with naloxone eliminated the morphine- induced depression on electrical current of calcium channels. Electric conductance of calcium channels did not change in the presence or absence of morphine. Conclusions Morphine inhibits electric current of L - type calcium channels of SK - N - SH human neuroblastoma cells in a manner of concentration dependence, probably via blockade of μ - opioid receptor ; but does not influence electric conductence of L - type calcium channels.