[Effect of Electroacupuncture at Distal and Proximal Acupoints on Expression of Spinal p 38 Mitogen-activated Protein Kinase and Cyclic Adenosine 3',5'-monophosphate in Rats with Lumbago].

OBJECTIVE: To observe the influence of Electroacupuncture (EA) stimulation of different distal-proximal acupoints combination groups on pain reaction, spinal p 38 mitogen-activated protein kinase (p 38 MAPK) expression and cyclic adenosine 3', 5'-monophosphate (cAMP) content in experimental lumbago rats. METHODS: Seventy-eight male SD rats were randomized into normal, model, sham operation, EX-B 2-BL 25 (proximal acupoints, PA), BL 40-BL 60 (distal acupoints, DA) and DA+PA groups. The lumbago model was established by implanting the autologous nucleus pulposus to the site close to the left L 5 dorsal root ganglion and the surface of dura mate of spinal cord. EA (2 Hz/100 HZ,1-3 mA) was applied at bilateral EX-B 2-BL 25 or BL 40-BL 60 or both for 20 minutes, once daily for 7 days. The mechanical pain threshold was measured, and the expression of p 38 MAPK in the lumbar spinal cord was detected by immunohistochemistry and Western blot, separately. The content of cAMP in spinal cord (L 4-L 6) was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: After mode-ling, the mechanical pain threshold percentages were significantly decreased on day 3, 5 and 7 (P<0.01), and after EA stimulation of DA,PA and DA+PA, the decreased pain threshold was significantly increased at the 3 time-points (P<0.01), and the effects of both PA and DA+PA were markedly superior to that of DA (P<0.05, P<0.01). Following modeling, lumbar spinal p 38 MAPK immunoactivity and protein expression, and cAMP content were obviously up-regulated (P<0.01). Compared with the model group, the levels of p 38 MAPK immunoactivity and protein expression in the 3 EA groups and the sham group, and cAMP contents in both PA and DA+PA groups (not in the DA and sham groups) were considerably down-regulated (P<0.01, P<0.05). CONCLUSIONS: EA stimulation of distal+proximal acupoints and proximal acupoints near the focus can raise pain threshold in lumbago rats, which may be associated with their effects in suppressing lumbago-induced increase of expression of spinal p 38 MAPK protein and cAMP content. The effects of EA of distal+proximal acupoints and proximal acupoints are better than those of EA of simple distal acupoints.

[Development of Researches on Mechanisms of Acupoint Combination for Some Disorders in Nerve-humoral-immunological Modulation].

Proper combination of acupoints is one of the core issues of acupuncturology, and is also one of the factors affecting clinical outcomes. In the present paper, the authors make a review on the development of researches on the underlying mechanisms of acupoint combination for some clinical disorders from nerve system, humoral factors and immunological regulation. The neural mechanism involves both the peripheral nervous system (mainly the segmental innervation) and central nervous system (spinal cord, brainstem, hypothalamus, cerebral cortex and cerebellum) , while the humoral factors chiefly contain neurotransmitters and hormones of the endocrine system. The immunological mechanisms involve immunocytes and cytokines. Generally speaking, following acupuncture stimulation of different combined-acupoints or acupoint groups, some synergistic effects may be produced. In fact, the relatively specific clinical effect may be easy to be obtained at the peripheral segmental innervations level.