皮肤经络的形态学基础及其立毛肌交感轴突反射传递机制

The Morphological Structure of the Skin along the Meridian and the Transmitting Mechanism of Arrector Pili Muscle-sympathetic Axon Reflex

我们把经络分为血管性与非血管性两大类 ,本文深入研究了非血管性经络———皮肤信息通路或皮肤交感神经敏感线的结构和活动机制。首先用宏观放射自显影的方法 ,在大鼠皮肤中显示出纵贯全身的系列交感物质分布线 ,连续清晰、左右对称 ,在头部和肢体末端形成环路。在沿物质分布线经过的背上部切断皮肤 ,可以显著阻断针刺“足三里”产生的针刺效应 ,说明皮肤的交感物质分布线即针刺信号传递线路 ,或者说 ,经络的形态学基础已经显现出来。进一步通过SPG荧光染色法观察到 ,位于大鼠皮肤的交感物质分布线来源于其下支配立毛肌的交感神经网络。结合我们过去关于拔除经线毛囊阻断针刺效应的实验 ,提出毛囊立毛肌在经络实质中的动力靶器官作用和实体形态学基础。最后 ,为探索针刺信号的传递机制 ,将大鼠环形剪毛 ,针刺后出现与宏观显影线走行一致的立毛线或立毛带 ,表明交感物质分布线即立毛线。皮内注射苯肾上腺素或垂体后叶素后出现相似的立毛线 ;在去中枢神经支配的皮条上也观察到延伸至在体皮肤上的立毛线 ;全部切断皮肤阻断了立毛线的跨切口传递 ;仅切断部分真皮则没有影响 ,如果在切断部分真皮的切口内微量注射普鲁卡因同样可以阻断立毛线的跨切口传递。

In this paper we studied the morphological structure and transmission mechanism of meridian (sympathetic sensitive lines along skin). ①The sympathetic substance lines(SSL) were displayed in 6 Wistar rats by macro autoradiography after intraperitoneal injection of tracer 125 I tyrosine; ②The adrenergic nerve endings innervating arrector pili musclelines were observed in 10 Wistar rats by fluorescent microscopy;③Following shearing the rat's hair as 12 ～16 rings from the head to the tail, punctured 'Zusanli' (ST 36) or the lower part of the back for 5 min, followed by intradermal injection of phenylephrine (20～60 μL, 0.125 mg/mL)or posterior pituitary hormone (20～40 μL, 0.375 U/mL) along SSL, the arrector pili line changes were observed; ④ After sectioning a skin strip with subcutaneous tissues (7 cm long an 2～2.5 cm width) covering the SAS line along the back of the rat and with only the layers of dermis and epidermis of the neck end connecting with the neck skin and recovered it original position, 30 min later, acupuncture of the skin strip was conducted for 5 min, or intradermal injection of phenylephrine was carried out in the tail end of the strip, then the production of the arrector pili line was observed.Results: ①After intraperitoneal injection of tracer 125 I tyrosine, continuous SSL appeared from the head to the foot, being symmetric on the bilateral sides, and connected each other to form loops at the head and the foot. When the upper back skin where the SSL passed was severed, the effect of acupuncture analgesia produced by stimulating ST 36 was blocked significantly. ②Under fluorescent microscopy the SSL were found to come from the adrenergic nerve endings innervating the arrector pili muscle. The acupuncture effect was blocked by depleting the hair follicles at the meridian line, indicating that the hair follicles and its arrector pili muscles along the SSL are the morphological structure of the meridian and serve as the dynamic target organs for long distance transmission of messages. ③In rats ( n =10) treated with acupuncture stimulation, a pilomotor line (about 2 cm width) could be seen along the back 5 min after acupuncture of ST 36, 4～15 min after injection of phenylephrine and 5～30 min after injection of posterior pituitary hormone, which was identical with SSL. ④In the skin strips (9 rats), a pilomotor line also appeared along the longitudinal axis 2～5 min after acupuncture, and 3～13 min after injection of the above mentioned medicines, indicating that the production of the pilomotor line is not dependent upon the central nervous system. After severing the skin to break the SSL, the pilomotor line did not cross the incision. When the incision only was limited to the dermis layer, the pilomotor line did not be influenced. If a shallow incision was treated with 2% procaine (20 μL), the pilomotor line was also blocked, showing that the pilomotor line is mediated by neural axon reflex in the reticular dermis/hypodermis layer. The propagation of acupuncture signals along the skin depends on the arrectores pilorum and the innervation of sympathetic nerves. ⑤Following shaving all the rat's hairs, the hair growth presented linear distribution from the head to the foot, which is identical with SSL.