Figure 9. Hypothetical signalling pathway of LPA‐induced itch.

Extracellular LPA activates the LPA₅ receptor and membrane lipids are metabolized mainly by PLD. PLD and iPLA₂ activity leads to intracellular LPA production and the resulting LPA directly activates TRPA1 and TRPV1 through interactions with KK672–673/KR977–978 and K710 (Nieto‐Posadas et al. 2012), respectively, leading to an increase in [Ca²⁺]_i. Thin grey lines, red circles and orange diamonds indicate hydrocarbon chains, phosphate groups and phosphorylcholine, respectively.