STUDY DESIGN: Evaluation of phospholipase A2 production according to cell type of human intervertebral disc. SUMMARY OF LITERATURE REVIEW: It was reported that the phospholipase A2 activity in human lumbar disc herniation was more active than that in other tissues. OBJECTIVES: The purpose of this study was to evaluate the differences between the cells of anulus fibrosus and nucleus pulposus when lactate was added to the culture medium. MATERIALS AND METHODS: Cells from the anulus fibrosus and nucleus pulposus of a human intervertebral disc were prepared enzymatically. After the monolayer was set up, the cells were divided to three groups and lactate doses of a 0mM, 2mM or 5mM were added respectively. At two week after lactate addition the production of phospholipase A2 was measured by Northern blotting. RESULTS: Cells of nucleus pulposus produced a small amount of phospholipase A2. Those of anulus fibrosus showed a high activity of phospholipase A2 production. The concentration of lactate did not influenced on the production of phospholipase A2. CONCLUSION: The anulus fibrosus has an important role in the production of phospholipase A2 and is thought to be related with generation of discogenic pain.