Effects of Anesthetics on tachykinin Receptors Expressed in Xenopus Oocytes

神经肽P物质（SP）和K物质（SK）调节脊髓内伤害性传递。spp和SK是在初级传入神经中发现的c纤维亚群所特有的。然而，麻醉药对P物质受体（SPR）的影响尚不清楚。在本研究中，我们研究了挥发性麻醉剂和乙醇对爪蟾卵母细胞中SPR表达的影响。我们使用全细胞电压钳检测了氟烷、异氟烷、安氟烷、乙醚和乙醇对爪蟾卵母细胞中表达的SPR介导的sp诱导电流的影响。所有测试的挥发性麻醉剂和乙醇在药理学相关浓度下抑制spr诱导的Ca^<2+>激活的C1^-电流。蛋白激酶C （PKC）抑制剂双吲哚酰马来酰亚胺I （GF109203X）增强sp诱导的CI^-电流。另一方面，GF109203X消除了所检测的挥发性麻醉剂和乙醇对SPR的抑制作用。这些结果表明，氟烷、异氟烷、安氟烷、乙醚和乙醇均能抑制SPR的功能，表明麻醉药物和乙醇对SPR抑制作用的作用机制涉及PKC的激活。

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.