The influence of thoracic spinal subarachnoid microinjection of Phentolamine (Phen

200ug/20ul)on the effect of electroacupuncture. (EA) at Neiguan (PC 6) was observed in 42 urethan-chloralose anesthetized rabbits. Results showed that: 1) EA of Neiguan((PC 6) could significantly promote recovery of elevated ST-segments and T-waves of electrocardiogram induced by acute myocardial ischemia (AMI). 2) subarachnoid microinjection of phentolamine had no marked influence on recovery of ST-segments and T-waves

but impeded recovery of blood pressure of post-AMI; 3 and 3) subarachnoid microinjection of phentolamine could significantly weaken or eliminate the effect of EA of Neiguan(PC 6) in accelerating recovery of ST-segments and T-waves of post-AMI. It denotes that αreceptors of intra-thoracic spinal cord participate in the action of EA of Neiguan(PC 6) in improving AMI

and the upper thoracic segment of the spinal cord is one of the links for connecting Neiguan and the heart.