A research team from McGill University in Canada has conducted a study whose findings support the theory that the nervous system has an important part to play in arthritis. The researchers are hoping that the results will contribute to the development of more effective treatments for this painful condition.
The study has provided more evidence that nerve-growth factor (NGF) plays a major role in arthritis. NGF is a protein which helps the nerves grow and survive but it also causes pain. The findings of the study indicate that bringing down NGF levels may be essential for developing more effective pain treatments.
The Canadian researchers worked with rats that had inflammatory arthritis in the ankle joint. The team focused on studying changes in the nerves and tissues around the affected joint. Sympathetic nerve fibres normally regulate blood flow in blood vessels but when the rats developed arthritis, these fibres started sprouting into the inflamed skin over the joint and enveloping the pain-sensing nerve fibres. The scientists also found more sympathetic fibres in the arthritic joint tissues.
In addition, the research showed elevated NGF levels in the inflamed skin. This mirrors the results of studies conducted with human subjects, with arthritic patients found to have significantly higher levels of NGF. The McGill team carried out an investigation into the part played by these abnormal sympathetic fibres, examining the effect of using an agent to stop the fibres from functioning. They established that this strategy led to reduced pain for the arthritic animals.