ARA290 in a rat model of inflammatory pain.

Chronic pain affects as many as one in five people. A proportion of patients with symptoms of neuropathic -pain do not have clinical signs of any obvious tissue or nerve injury. Such patients include those with diffuse limb pain, back pain, and complex regional pain syndrome type 1. These patients remain a clinical enigma. However, through the development of the neuritis model, it has become apparent that local nerve inflammation in the absence of gross pathology (i.e., axonal degeneration and demyelination) may underlie part of the mechanisms of pain. In this chapter, we describe a method to induce the neuritis model. We also describe in detail a reliable method to test for mechanical allodynia and heat hyperalgesia. Data that demonstrates the potential benefits of the neuroprotective agent ARA290 in reducing pain behavior in the neuritis model are presented.