BACKGROUND:Varying degrees of inflammatory responses occur during lumbar nerve root compression.Studies have shown that nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) are involved in secondary disc inflammation.OBJECTIVE:To observe the effects of warm acupuncture on the ultrastructure of inflammatory mediators in a rat model of lumbar nerve root compression,including NOS and CGRP contents.DESIGN,TIME AND SETTING:Randomized,controlled study,with molecular biological analysis,was performed at the Experimental Center,Sixth People's Hospital Affiliated to Shanghai Jiao Tong University,between September 2006 and April 2007.MATERIALS:Acupuncture needles and refined Moxa grains were purchased from Shanghai Taicheng Technology Development Co.,Ltd.,China;Mobic tablets were purchased from Shanghai Boehringer Ingelheim Pharmaceuticals Co.,Ltd.,China;enzyme linked immunosorbent assay (ELISA) kits for NOS and CGRP were purchased from ADL Biotechnology,Inc.,USA.METHODS:A total of 50,healthy,adult Sprague-Dawley rats,were randomly divided into five groups:normal,model,warm acupuncture,acupuncture,and drug,with 10 rats in each group.Rats in the four groups,excluding the normal group,were used to establish models of lumbar nerve root compression.After 3 days,Jiaji points were set using reinforcing-reducing manipulation in the warm acupuncture group.Moxa grains were burned on each needle,with 2 grains each daily.The acupuncture group was the same as the warm acupuncture group,with the exception of non-moxibustion.Mobic suspension (3.75 mg/kg) was used in the oral drug group,once a day.Treatment of each group lasted for 14 consecutive days.Modeling and medication were not performed in the normal group.MAIN OUTCOME MEASURES:The ultrastructure of damaged nerve roots was observed with transmission electron microscopy;NOS and CGRP contents were measured using ELISA.RESULTS:The changes of the radicular ultramicrostructure were characterized by Wallerian degeneration;nerve fibers were clearly demyelinated;axons collapsed or degenerated;outer Schwann cell cytoplasm was swollen and its nucleus was compacted.Compared with the normal group,NOS and CGRP contents in the nerve root compression zone in the model group were significantly increased (P