不同给药方式对P2X_1受体介导大鼠肠系膜动脉收缩反应的影响

目的研究不同方式给予α,β-MeATP对肠系膜动脉P2X1受体介导血管收缩反应的影响。方法制备大鼠离体肠系膜动脉环标本,采用非累积给药法和单浓度给药法两种方式给予α,β-MeATP,记录药物诱发的等长收缩反应。结果两种给药方式给予α,β-MeATP(10-7-10-4mol·L-1)均可使大鼠离体肠系膜动脉产生浓度依赖性收缩反应。以KCl最大收缩反应或以标本湿重标化α,β-MeATP诱发的收缩反应时,α,β-MeATP单浓度给药的收缩反应均大于非累积给药(P<0.01)。以标本湿重标化时,10-4mol·L-1浓度α,β-MeATP诱发的收缩反应分别是(0.73±0.10)g·mg-1(单浓度组)和(0.38±0.05)g·mg-1(非累积组);以KCl最大收缩反应标化时,分别是(53.17±6.0)%(单浓度组)和(36.78±5.71)%(非累积组)。在α,β-MeATP非累积给药组120mmol·L-1KCl诱发的动脉收缩反应小于单浓度给药组和NA对照组(P<0.01)。结论在大鼠肠系膜动脉,非累积给予α,β-MeATP降低P2X1受体介导的收缩反应以及高钾诱发的收缩反应,该给药方式可能导致错误的实验结论 。

Inhibition of P2X_7 Receptor by Extracts of Chinese Medicine

Objective： To investigate the influence of Acorus gramineus （Soland）, a crude extract, SCP01, and a purified component, SCP02, and of Rosmarinus officinalis L., X0728 on human mast cells （HMC-1 Cell Line）. Methods： Current-voltage of P2X7 receptors on human mast cell membrane activated by ATP was recorded by the whole-cell patch clamp technique. Results： The current at -100 mV mediated by P2X7 was inhibited by （27.6 ± 2.0） % in the presence of 40 μg/mL SCP01 and by （29.5 ± 2.2） % in the presence of 40 μg/mL SCP02, which was identified as α-asarone. 42 μg/mL of the commercially available α-asarone inhibited the P2X7-mediated current by （52.2 ± 2.0） %. In contrast to SCP01 and SCP02, 40 μg/mL X0728 provoked stimulation of the current by （28.6 ± 2.8） %. All effects were voltage- independent. Conclusion： The inhibition of P2X7 by α-asarone will inhibit intracellular calcium increase and this may account for the inhibition of reported excitotoxic cell death. The pharmacological function of P2X7 stimulation by X0728 needs further investigation.