目的:探讨18β-甘草次酸对Wistar大鼠脑微动脉平滑肌细胞间缝隙连接的影响,为寻求强效和可逆的缝隙连接阻断剂提供实验依据。方法:去除脑微动脉段外层结缔组织后,应用全细胞膜片钳技术,观察不同种类的缝隙连接阻断剂对Wistar大鼠脑微动脉段上平滑肌细胞膜电容(Cinput)、膜电导(Ginput)和膜电阻(Rinput)的影响。结果:(1)Wistar大鼠脑微动脉段上平滑肌细胞Cinput高于消化分离的单个平滑肌细胞。(2)18β-甘草次酸(18pGA)能浓度依赖性的抑制Wistar大鼠脑动脉平滑肌细胞间的缝隙连接,IC50分别为2.0μM。当18βGA100μM时,Wistar大鼠脑微动脉段上平滑肌细胞的Cinput、Ginput或Rinput与单个平滑肌细胞十分接近。结论:1813GA可以浓度依赖性的抑制Wistar大鼠脑微动脉平滑肌细胞间缝隙连接。
Objective: To explore the influence of the blockers on gap junction between cerebral arteriolar smooth muscle cells in Wistar rat, and to provide experimental evidence for seeking the powerful and reversible gap junction blockers. Methods: The outer layer's connective tissue of the cerebral arteriolar segments was removed. Whole-cell patch clamp recordings were used to observe the impaction of the different kinds of gap junction blockers on the membrane's input capacitance (Cinput), input conductance (Ginput) and input resistance (Rinput) in the arteriolar segment smooth muscle cells. Results: (1) The Cinput and Ginput in Wistar rat arteriolar segment smooth muscle cells were much higher than those in the dispersed cells, and there was significant difference(P〈0.05). (2) 18β-Glycyrrhetinicacid (1813GA), concentration-dependently suppressed gap junction. IC50 were 2.0 μM and there was no significant difference (P〉 0.05). After application of 18βGA (100μM), the Cinput, Ginput and Rinput in situ cells were very close to those in dispersed cells. Conclusion: 18βGA concentration-dependent inhibits Wistar rat's gap junction between arterial smooth muscle cells and the inhibitory potency is similar.