title: Transient receptor potential ion channels: powerful regulators of cell function.
abstract: OBJECTIVE
  This article reviews the current understanding of transient receptor potential ion channels (TRP channels) in health and disease.
  
  
  BACKGROUND
  Transient receptor potential ion channels are a group of 27 channels that are expressed in all tissues. These channels play important roles in surgically important problems, such as chronic pain, susceptibility to infection, hypothermia, and some cancers.
  
  
  METHODS
  A literature search was performed. This review focuses on the role of TRP channels in a few surgically important disease processes, such as pain, inflammation, airway diseases, and malignant melanomas. In addition, we discuss some of the structural properties that are important for the activation of TRP channels.
  
  
  RESULTS
  TRPA1 and TRPV1 are expressed on pain fibers and play an important role in the development of chronic pain, such as chemotherapy-related neuropathic pain. Deletion of TRPA1 and TRPV1 suppresses the development of chronic pain, and blockers of TRPA1 and TRPV1 show promise as a new class of painkillers. Furthermore, several TRP channels are expressed on immune cells. Macrophages express at least 3 different TRP channels, and the properly balanced activation of all these channels together allows normal macrophage function. Deletion of any of these channels results in impaired macrophage function and increased susceptibility to infection. Because several of these TRP channels on macrophages are temperature sensitive, they may comprise the link for hypothermia-related infectious complications in trauma, and to a lesser degree, in elective surgical patients.
  
  
  CONCLUSIONS
  Transient receptor potential ion channels are involved in several surgically important disease processes. Activation or blockade of these channels offers new therapeutic opportunities. Pharmacologic activation or blockade of TRP channels may offer new treatment options in surgical patients for the management of pain and infections.
authors.affiliation: *Hiram C. Polk Jr MD Department of Surgery, Price Institute of Surgical Research, and †Diabetes and Obesity Center, University of Louisville School of Medicine, Louisville, KY.
authors.forename: Adrian T
authors.initials: AT
authors.lastname: Billeter
authors.forename: Jason L
authors.initials: JL
authors.lastname: Hellmann
authors.forename: Aruni
authors.initials: A
authors.lastname: Bhatnagar
authors.forename: Hiram C
authors.initials: HC
authors.lastname: Polk
mesh_terms: D000700:Analgesics / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D002211:Capsaicin / Q000627:therapeutic use; D059350:Chronic Pain / Q000378:metabolism*; D000068736:Duloxetine Hydrochloride; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D010149:Postoperative Pain / Q000188:drug therapy / Q000378:metabolism; D012140:Respiratory Tract Diseases / Q000378:metabolism; D013530:Surgical Wound Infection / Q000378:metabolism / Q000517:prevention & control; D000074025:TRPA1 Cation Channel; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D013876:Thiophenes / Q000627:therapeutic use; D050051:Transient Receptor Potential Channels / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D013876:Thiophenes; D050051:Transient Receptor Potential Channels; D000068736:Duloxetine Hydrochloride; D002211:Capsaicin