Forskolin抑制大鼠胃窦环行平滑肌自发性收缩运动

Forskolin inhibits spontaneous contraction of gastric antral smooth muscle in rats

本文旨在探讨环磷酸腺苷(cyclic adenosine monophosphate,cAMP)对胃窦环行平滑肌功能的调节作用。分离大鼠胃窦环形肌条,用多道生理记录仪观察腺苷酸环化酶(adenylyl cyclase,AC)直接激活剂Forskolin对胃平滑肌自发性收缩活动的影响,并用ELISA法测定灌流液中cAMP生成量的变化。结果显示,Forskolin浓度依赖性地抑制胃窦环形肌条自发性收缩活动,降低肌条的收缩振幅和频率,使收缩运动基线明显下移。Forskolin浓度依赖性地提高灌流液中的cAMP含量,且灌流液中cAMP含量与肌条收缩振幅呈显著负相关。Forskolin对大鼠胃窦环行肌自发性收缩活动的抑制作用可被cAMP依赖性的蛋白激酶(cAMP-dependent protein kinase,PKA)抑制剂H-89所阻断。以上结果提示,Forskolin可通过增加cAMP含量激活PKA途径,从而抑制大鼠胃窦环行平滑肌的自发性收缩活动。

The aim of the present study was to investigate the effects of cyclic adenosine monophosphate （cAMP） on rat gastric antral circular smooth muscle function. Forskolin, a direct activator of adenylyl cyclase （AC）, was used to observe the influences of cAMP. Multi-channel physiological recorder was used to record spontaneous contraction activity of gastric antral circular muscle from Wistar rats. And ELISA method was used to detect the change of cAMP production in perfusate. The results showed that forskolin concentra- tion-dependently suppressed the amplitude and frequency of the spontaneous contraction of the gastric antral muscle, and lowered the baseline of contraction movement significantly. Forskolin concentration-dependently increased the production of cAMP in the per- fusate, which showed a significant negative correlation with the contraction amplitude of gastric antral ring muscle. The inhibitory ef- fect of forskolin on spontaneous contraction activity of rat gastric antral circular muscle could be blocked by cAMP-dependent protein kinase （PKA） inhibitor H-89. These results suggest forskolin increases cAMP production and then activates PKA pathway, resulting in the inhibition of the spontaneous contraction activity of rat gastric antral circular smooth muscle.