Microdialysis of Inflammatory Mediators in the Skin: A Review

Abstract

Skin microdialysis is an established method for in vivo sample collection from the extracellular fluid space. This method has been extensively used in studies of inflammatory reactions in the skin of animals and humans. Skin microdialysis consists of the implantation of semi-permeable probes into the upper dermis, perfusion with a physiological buffer, and the recovery of the substances that diffused from the skin into the perfusion fluid. Microdialysis allows the simultaneous assessment of the temporal variations of inflammatory mediator release in the skin as well as the monitoring of vascular and sensory functions. By the aid of this technique, potential associations can be found between functional changes and a variety of substances and mediators released at the site of interest. This allows further insights into the possible mechanisms underlying physiological and pathophysiological events in the skin, including cutaneous inflammation. This review provides a comprehensive but not exhaustive review of the use of microdialysis in studies of experimental and clinical inflammatory reactions in the skin in animals and humans.

Preclinical and human surrogate models of itch

“…Besides spontaneous scratching, alloknesis can be assessed by observing itch‐related responses following von Frey or brush stimulation . It is also possible to assess vascular permeability using Evans blue dye, and inflammatory mediators can be analysed by microdialysis or biopsies …”

“…20,25 It is also possible to assess vascular permeability using Evans blue dye, and inflammatory mediators can be analysed by microdialysis or biopsies. 12,26,27…”

A neglected organ in multiple organ failure – ‘skin in the game’?

“…In these patients, the areas of skin investigated are obviously severely injured, and microdialysis in these regions demonstrated significantly higher levels of glucose, lactate, serotonin and cortisol in comparison to plasma (where levels of all substances were normal or reduced). These findings add to the understanding of susceptibility to infection, wound repair, oedema generation and infection by group A Streptococcus pyogenes . In regard to ischaemia/reperfusion injury, the innate immune system, represented by the key‐mediator of complement activation C3a, was identified as a sensitive early marker of reperfusion injury in both burn patients and free muscle flap reconstructive surgery patients .…”

“…Notably, samples were acquired at specific time‐points only, while serial sampling with more brief intervals might be preferable to follow the dynamic process of sepsis. Microdialysis is another invasive method, which enables serial, almost real‐time sampling of metabolites and inflammatory markers . A microdialysis catheter consists of an implantable miniaturized probe with a semipermeable membrane, allowing diffusion of extracellular substances into the lumen of the probe.…”

Preclinical Study of Tacrolimus Ointment for Prevention of Its Systemic Absorption in Atopic Dermatitis Model Mice According to Their Skin Conditions

“…[19][20][21][22][23][24] The tested skin in the clinical studies was described as lesional skin or was classi ed broadly into mild , moderate , and severe based on the extent or severity of AD. Inflammatory responses, such as dysfunction of stratum corneum (SC) barrier, [25][26][27] alteration of skin blood flow, 28) vascular hyperpermeability, 29) and leakage of plasma components, 30) occur in AD skin. The inflammatory reaction is complex and the dynamic process can affect the pharmacokinetics of TL after application of TL ointment on AD skin.…”