| Lumbar disc herniation is a common disease for human beings and is a most common cause of low back pain and radiculopathy. Hie theory that low back pain and sciatica was the result of the compression nerve root by hemiated inter-vertebral disc was accepted for several decades since Mixter and Bar initially reported in 1934. However, the severe symptoms without apparent nerve root compression was often seen clinically and the size of hemiated disc was not correlated with the clinical symptoms. These phenomenon could not be explained by simple mechanical nerve root compression. There should be other reasons to explain the above apparent pardox. Recent studies have shown that there was inflammatory reaction around the hemiated disc tissue and the characteristics of this kind of inflammation was the infiltration of inflammatory cells, mainly by macrophages. The infiltrated macrophages release many cytokines and inflammatory mediators which damage the nerve roots, causing low back pain and sciatica together with mechanical compression. On the other hand the infiltrated macrophages were considered to play an important role in the clearance and the absorption of hemiated disc. With the advances of imaging techniques, spontaneous regression has been increasingly reported. Many researchers believed the spontaneous regression of hemiated discs was the results of the phagocytosis by infiltrated inflammatory cells, mainly by macrophages. However, the precise mechanism of the resorption of hemiated discs remains unknown.Chemokines are a family of pro - inflammatory cytokines with potent chemo-tactic activity for leucocytes both in vitro and in vivo . The functions of these chemokines are mediated by chemokine receptor. One receptor has the ability to combine with several chemokines and one chemokine could also combined with several receptors. The study regarding chemokines and their receptors has made great progress in recent 10 years. Nowadays more than 40 chemokines and their receptors have been identified and classified. They are a family of small secretedmolecules which consist of 70 ~ 100 amino acids. The main functions of chemo-kines are to control the activities of leucocytes and play important role in modulating immunological reaction. Chemokines are classified into CXC, CC, C and CX3C subfamilies according to specific cysteine motif of N - terminal. Each chemokine exerts its chemotactic effects via G - coupled receptors on the cell surface. Monocyte chemoattractant protein - 1 ( MCP-1) and macrophage inflammatory protein-la (MlP-la) belong to CC subfamily. Their primary function is macrophage chemotacxis and activation, to promote the transition from monocyte to macrophage, attract monocytes from circulatory system to target tissue. Nowadays the precise mechanism of inflammatory cell infiltration around the lumbar herniated discs is mostly unclear. The functions and effects of chemokines in herniated lumbar discs are still unknown.Objectives; To clarify the mechanism of macrophage infiltration around lumbar disc hemiation, ascertain the effects of MCP-1 and MlP-la on the process of macrophages infiltration and the mechanism of macrophage recruitment , discuss the mechanism of low back pain and sciatica and the cause of the regression of herniated lumbar discs.Methods1. Materials:1.1 36 lumbar disc specimens were obtained from the 30 patients who underwent surgery for persistent radicular pain. There were 18 male and 12 female in the group. The average age was 36(22 -48years). The specimens were divided into three subgroups: annulus intact( AI, n =6 ) , extrusion (EXT, n = 12) , sequestration (SEQ, n = 18). Ten intervertebral disc specimens of control group were from patients undergoing anterior spinal surgery for scoliosis ( n = 2) and spinal fracture(n =8). The ages of the two patients with scoliosis were 12 and 14 years, both were female. The average age of the other 8 patients of spinal fracture was 26 (range 18 ~34) with 5 men and 3 women. All tissue specimen were treated according to an id...
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