Effects of Anesthetics on tachykinin Receptors Expressed in Xenopus Oocytes

神经肽P物质（SP）和K物质（SK）调节脊髓内的伤害性传递。SP和SK是在初级传入神经内发现的C纤维亚群所特有的。然而，麻醉剂对P物质受体（SPR）的影响尚不清楚。在这项研究中，我们研究了挥发性麻醉剂和乙醇对非洲爪蟾卵母细胞表达SPR的影响。我们研究了氟烷，异氟烷，恩氟烷，乙醚和乙醇对SP诱导的电流介导的SPR表达在非洲爪蟾卵母细胞，使用全细胞电压钳的影响。所有的挥发性麻醉药和乙醇都能抑制SPR诱导的Ca^2+-激活的C1^-电流，浓度与对照组相同。蛋白激酶C（PKC）抑制剂双吲哚马来酰亚胺I（GF 109203 X）增强SP诱导的Cl ^-电流。另一方面，GF 109203 X取消了对SPR的抑制作用的挥发性麻醉剂检查和乙醇。这些结果表明，氟烷，异氟烷，恩氟烷，乙醚，和乙醇抑制SPR的功能，并建议PKC的激活参与了麻醉剂和乙醇对SPR的抑制作用的作用机制。

The neuropeptide substance P (SP) and substance K(SK) modulate nociceptive transmission within the spinal cord. SPand SK are unique to a subpopulation of C-fibers found within primary afferent nerves. However, the effects of anesthetics on the substance P receptor (SPR) are not clear. In this study, we investigated the effects of volatile anesthetics and ethanol on SPR expressed in Xenopus oocytes. We examined the effects of halothane, isoflurane, enflurane, diethyl ether, and ethanol on SP-induced currents mediated by SPR expressed in Xenopus oocytes, using a whole-cell voltage clamp. All the volatile anesthetics tested and ethanol inhibited SPRinduced Ca^<2+>-activated C1^- currents at pharmacologically relevant concentrations. The protein kinase C (PKC) inhibitor bisindolylmaleimide I (GF109203X) enhanced the SP-induced CI^-currents. On the other hand, GF109203X abolished the inhibitory effects on SPR of the volatile anesthetics examined and of ethanol. These results demonstrate that halothane, isoflurane, enflurane, diethyl ether, and ethanol inhibit the function of SPR, and suggest that activation of PKC is involved in the mechanism of action of anesthetics and ethanol on the inhibitory effects of SPR.