In recent years, ion channels have emerged as new therapeutic targets for pain. Among these channels, ASICs (Acid Sensing Ion Channels) are of particular interest because they are directly activated by extracellular acidity, which is a major cause of pain. Indeed, many painful conditions such as ischemia, inflammation, tumor development or tissue incision are accompanied by tissue acidification. ASIC are excitatory ion channels that are expressed in neurons, including nociceptive sensory neurons. In humans, the use of amiloride, a nonspecific inhibitor of ASICs, has demonstrated their role in the perception of pain induced by subcutaneous injections of acidic solutions. ASICs thus appear as new candidates capable of mediating pain in humans. A growing number of data suggests that, in addition to protons, ASICs may also be activated by one or more endogenous compounds produced during inflammation. The purpose of this research project is to identify these compounds by testing the effects of human inflammatory exudates on ASICs activity. The discovery of such compounds would definitely validate ASICs as novel therapeutic targets for pain treatment in humans

Inclusion Criteria:

• septic arthritis
• gonarthrosis in push-inflammatory
• microcrystalline arthropathies
• chronic inflammatory rheumatism

Exclusion Criteria:

• refusal to participate in the protocol

(osteoarthritis, chondrocalcinosis, gouty arthritis, rheumatoid arthritis)