Comparison of pain induction by ω-hydroxy PUFAs, 20-HETE, 20-HEPE, and 22-HDoHE, in naïve rats. (A) Intraplantar injection of the corresponding methyl esters (1 µg in 1:9 EtOH/saline) revealed ω-6 hydroxy PUFA (20-HETE), but not ω-3 hydroxy PUFAs (20-HEPE and 22-HDoHE), changed mechanical withdrawal sensitivity in the von Frey assay (Two Way Analysis of Variance, Holm-Sidak post hoc p < 0.001, n = 6, male Sprague Dawley rats). (B) Intraplantar injection of 20-HETE (1 µg of 20-HETE methyl ester in 1:9 EtOH/saline) decreased mechanical withdrawal thresholds in a dose-dependent manner indicating that pain behavior was localized to the injected (ipsilateral) hind paw (Two Way Analysis of Variance, Holm-Sidak post hoc p = 0.005, n = 6, male Sprague Dawley rats).