炎症痛敏大鼠背根神经与细胞Ih通道特征的变化及其参与痛？…

Ih CHANNEL CHARACTERISTICS IN DRG CELIS OF ARTHRITIC RAT AND ITS POSSIBLE ROLE IN HYPERALGESIA

摘要:

目的：超极化激活电流（Ｉｈ）通道对神经元动作电位的爆发超重要作用，本工作检验其在炎症痛中的作用。方法：用完全弗氏佐剂诱发关节炎模型，用全细胞电流钳、电压钳技术研究炎症后大鼠背根神经节（ＤＲＧ）细胞Ｉｈ通道的特性。结果：炎症大鼠ＤＲＧ细胞Ｉｈ通道的翻转电位、最大电流密度没有改变，说明Ｉｈ通道的结构及表达的数量没有变化。但Ｉｈ通道的半激活电位向去极化移动，说明Ｉｈ的活性增加；电流钳记录表明，炎症大鼠Ｄ

Abstract:

Summary Aim: The hyperpolarization activated current(I h) channel plays an important role in the firing neuron action potential. In the present study we explore the role of I h in the production of inflammation induced hyperalgesia. Metholds: Complete Freund's adjuvent (CFA) induced arthritic rat modelwas used to study the I h channel characteristics in DRG cells by appling whole cell current clamp and voltage clamp techniques. Results: No significant differences were found between the arthritic rats and the control rats in the reversal potential and current density of the DRG cells, suggesting that the structure and amount of I h channel remained the same in arthritic rats. However, the half activated potential (V 1/2 ) became more positive, demonstrating an enhanced I h channel activity. The current clamp recordings in cells expressing I h current revealed a wider action potential (AP) and increased action potential frequency. Conclusion: The widening of AP and increase in AP frequency may cause abnormal AP firing in the primary afferent and increase the release of neurotransmitter in the DRG cell's central and peripheral terminals, resulting in an inflammatory hyperalgesia. Key words Inflammatory hyperalgesia; DRG; I h channel; Action potentialery and the prognosis of hilar cholangiocarcinoma. Methods We studied retrospectively 58 cases of hilar cholangiocarcinoma which entered our department between June 1987 and October 1998. The postoperative liver functional recovery and mortality and morbidity between unilateral ( n =27) and bilateral ( n =31) bile duct drainage groups were compared. Results The liver function in bilateral drainage group was nearly normal within 6 weeks after operation. The ALb level of unilateral drainaged patients recovered gradually to normal after operation, and the TBIL and ALT decrease nearly to the normal range within 6 weeks after operation. The AKP decreased within 2 postoperative weeks, then steadily increased. The differences of perioperative complication rate and mortality of the two groups showed no significance. Conclusion The data showed that the liver function can recover to some extent by unilateral bile duct drainage, and unilateral drainage operations are the choice for hilar cholangiocarcinoma that can not be excised now.