Substance P In The "neiguan" And The Role Of Cardiac Autonomic Nervous Path

Objective: Anti-AMI (acute myocardium ischemia) effect of electric needle stimulating PC6 was to be studied according to ECG, heart sympathetic and vagi nerve discharging, cardiac muscle ultrastructure of AMI rats being needled guided by the meridian (acupoints)-viscera relation theory, especially PC6-heart relation. Potential active substance and action passage was to be found out for PC6-heart relation on autonomic nerve anti-AMI effect to understand the regulating mechanism of nervous endocrinological system so as to provide reliable experimental evidence for PC6-heart relation theory with SP of autonomic nerve and NOS as observing index. Methods: 30 SD rats were randomly divided into normal group(group A), controlled group (group B), electric needle groups (group C), with 10 rats in each group. AMI models were induced by Pit iv, treated by the left PC 6 stimulated with electric needle. For each group, cervical vagi and sympathetic nerves were isolated, models were made 3 min later, and the BL-420E⁺ was applied to record vagi and sympathetic nerve dischargingo For group A, myocardium pieces were taken for electron microscope section 0 min,3 min,8 min,t3 rain,23rain, after the recording times being marked. In 23 min, the spinal cord and brain were taken as section for the immunohistochemistry determination of SP. For group B and group C , record times were marked correspond to that in group A in 0 min,5 min,10 min,20 min, in before and after the model establishment respectively. In 20 min, the spinal cord and brain were taken as section for the immunohistochemistry determination of SP. For group C, 5 min after the model establishment, PC6 on the left arm (between the ulna and radius 3mm from waist joint, refer to "Rats Acupoints Figure" of Hua Xing Bang, ) was stimulated with electric needle high and low frequency (from 8 to 80Hz, alternatively for 14 times/min, voltage: 1.5 v, current: 1 mA) for 5 rain. The needle without electric stimulator remained for 10 min. Observation index as follows:(1) Frequency (Hz) of vagi and sympathetic nerve discharging of different times (10 samples were taken 1 min after each time, the sample time lasts for 1 s, for the mean of sum); (2) Paraventricular nucleus (PVN) of hypothalamus, medullary bulb and vagi nerve complex, spnal lateral crus OD of SP (HPIAS-1000 was applied to scan the brown yellow and blue random mating signal. Three corresponding visual fields of four slices from PVN of hypothalamus, medullary bulb and vagi nerve complex, C₈-T₂ were taken. Then the averages of the sum of 12 visual fields for each index were the SP immunopositive OD) were observed.Results: (1). Autonomic nerve discharging: the sympathetic and vagi nerve discharging frequency differed not so obviously before and after in group A.For group B , The vagi nerve discharged more and sympathetic nerve discharged less each time from 0 min to 20 min after the model being made, It was significant comparing with the data before the model being made (P＜0.05). It also was significant comparing with group A (P＜0.05).For group C, vagi nerve discharged less and sympathetic nerve discharged more after being stimulated by the electric needle (that is 10 min to 20 min after the model being made). There was no significance comparing with that in group A, and showed significance comparing with that in group B; (2) OD of SP: the OD of SP in PVN of hypothalamus, medullary bulb and vagi nerve complex, spinal lateral crus were 115.4±12.2,43.3±12.1 in group A; OD of SP was lower in group B' than that in group A and the difference was significant between groups (P＜0.05). SP were more in any parts in group C than in group A and group B and the difference was significant between groups (P＜0.05).Conclusions: (1) Electric needles stimulating PC6 inhibits AMI vagi nerve and excites sympathetic nerve and therefore promote the recovery of AMI; (2) Electric needles stimulating PC6 promotes the SP positive expression in PVN of hypothalamus, medullary bulb and vagi nerve complex, C₈-T₂ spinal lateral crus. The SP in spinal lateral crus increases and further promotes the sympathetic nerve discharging and inhibits vagi nerve. Sympathetic nerve is to contract the heart muscles and promote myocardial circulation, while the vagi nerve inhibited decreases the myocardial impairment; (3) The new ideas: Autonomic nerve adjusting effect on AMI was studied, and PC6-heart relation was discussed from the view of SP of autonomic nerve. Few reports have been published on the antagonistic effect on SP was firstly observed with receptor blocker NK₁ⅳ.