四逆汤对高钾和去氧肾上腺素收缩主动脉环效应的影响

Effect of SINI TANG on contraction of aortic rings induced by high K^+ and phenylephrine

目的 研究四逆汤对高钾和去氧肾上腺素 (Phe)收缩大鼠离体主动脉血管环效应的影响。方法 观察四逆汤在主动脉环上拮抗 KCl (60 mmol/ L )和 Phe (1× 10 - 9～ 1× 10 - 4mmol/ L )的收缩血管作用 ,分别用普萘洛尔(Pro,3× 10 - 6 m mol/ L)和 Bay K8644(BK,1× 10 - 5 mm ol/ L)干预探讨其机制。结果 四逆汤减弱累积浓度的Phe收缩血管的效应 ,最大值 (Tmax)减小 ,Pro不影响四逆汤的拮抗作用 ;四逆汤减小高钾刺激血管的最大收缩效应 ,BK不能恢复这种效应。结论 四逆汤使 Phe的量效曲线右移 ,并减小其最大效应值 ,表现为非竞争性拮抗作用 ;减小高钾收缩血管的作用 ,Ca2 +开放剂 BK不能恢复四逆汤的抑制作用。四逆汤能阻断 α1受体 。

Object To study the effects of SINI TANG (SNT) on the rat aortic rings pre-contracted by high K + and phenylephrine (Phe). Methods The effects of SNT on the aortic rings in the presence of 60 mmol/L KCl and Phe (1×10 -9 -1×10 -4 mmol/L) were observed and t heir me chanisms were studied after treatment with Propranolol (Pro, 3×10 -6 mmol/ L) and Bay K8644 (BK, 1×10 -5 mmol/L) as tool drugs. Results SNT inhibited the contraction induced by cumulative Phe and decreased the maximum tension (T max ); Pro couldn't influe nce the effects of SNT. SNT attenuated the amplitude of contractile effect of hi gh K +; BK couldn't reverse the effects of SNT. Conclusion SNT can shift the dose-response curve to the right and decrease the T max . It shows that SNT is a kind of noncompe titive antagonism. SNT decreases the effect of high K + against contraction of the artery. BK, a L-type Ca 2+ channels activator, couldn't recover the inhibition induced by SNT. The results suggest that SNT inhibit α 1 recep tor, while calcium channel may not be involved in attenuating the effect of SNT on high K +-induced contraction.