Age-related effects of cocultured rat nucleus pulposus cells and macrophages on nitric oxide production and cytokine imbalance.

Study Design: A study of age-related effects on nitric oxide (NO) and cytokine production in cocultured rat nucleus pulposus (NP) cells and macrophages.

Objective: To evaluate the effects of age on NO and cytokine production in an in vitro model of cocultured NP cells and macrophages.

Summary Of Background Data: It is well known that the clinical characteristics of lumbar disc herniation differ with age.

Low-intensity pulsed ultrasound stimulation enhances TIMP-1 in nucleus pulposus cells and MCP-1 in macrophages in the rat.

Recent studies have reported that low-intensity pulsed ultrasound (LIPUS) stimulates cell proliferation and proteoglycan production in rabbit intervertebral disc cells, and moreover promotes the secretion of MCP-1 (monocyte chemotaxis protein-1) from macrophages in a disc organ culture model. These findings suggest the possible application of LIPUS for biological repair of disc degeneration and herniation. Although the mechanisms involved are not well understood, several cytokine pathways may play a role.