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.
Transient receptor potential ion channels are a group of 27 ion channels that are found in all tissues. These channels are involved in pain sensation and regulation of immune function and temperature. The causal role of these channels in many diseases makes them interesting targets for the development of new therapies.
*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.
Reprints: Adrian T. Billeter, MD, PhD, Department of Surgery, University of Heidelberg Hospital, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany. E-mail: firstname.lastname@example.org; or Hiram C. Polk, Jr, MD, Hiram C. Polk Jr MD Department of Surgery, University of Louisville School of Medicine, Louisville, KY 40292. E-mail: email@example.com.
Supported in part by the Price Trust Fund and by the Joint Royal College of Surgeons of Edinburgh (RCSEd)/James and Emmeline Ferguson Research Fellowship Trust. The funding source had no role in the production of the manuscript.
Disclosure: Dr Billeter holds the Joint Royal College of Surgeons of Edinburgh (RCSEd)/James and Emmeline Ferguson Research Fellowship. We declare that no author has competing financial interests. The authors declare no conflicts of interest.
Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.annalsofsurgery.com).