PET-scan shows peripherally increased neurokinin 1 receptor availability in chronic tennis elbow: a picture of neurogenic inflammation?
2011 (English)In: Pain, ISSN 0304-3959, E-ISSN 1872-6623Article in journal (Refereed) Submitted
In response to pain, neurokinin 1 (NK1) receptor availability in the central nervous system is altered in the dorsal horn of the spinal cord as well as in the brain. But the NK1 receptor and its primary agonist, substance P, also play a crucial role in peripheral tissue in response to pain, as part of neurogenic inflammation. However, little is known about alterations in NK1 receptor availability in peripheral tissue in chronic pain conditions and very few studies have been performed on human beings. We therefore performed positron emission tomography (PET) with the NK1 specific radioligand [11C]GR205171 in ten subjects with chronic tennis elbow. We demonstrated increased NK1 receptor availability in the affected arm as compared with the unaffected arm, measured as differences between the arms in number and volume of pixels > 2.5 SD above reference as well as signal intensity of this volume. We conclude that in addition to alteration of the NK1 receptor in the CNS, there is also activation, or up-regulation of the NK1 receptor in the peripheral, painful tissue in a chronic pain condition. We interpret this increased NK1 receptor availability as part of ongoing neurogenic inflammation and suggest that this is part of the cause of chronic tennis elbow.
Place, publisher, year, edition, pages
PET, chronic, pain, substance P, neurokinin 1, tennis elbow, epicondylitis, epicondylosis
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-160048OAI: oai:DiVA.org:uu-160048DiVA: diva2:447881