518 Role Of TLR4 In chronic relapsing itch induced by subcutaneous capsaicin injection in neonatal rats

Despite the high prevalence of chronic dermatitis and accompanied intractable itch, therapeutics that specifically target itching have low efficacy. Increasing evidence suggests TLRs contribute to immune activation neural sensitization; however, their roles in itch remain elusive. Here, we show RBL-2H3 mast cell line expresses TLR4 treatment with a antagonist opposes LPS dependent increase mRNA levels Th2 innate cytokines. The pathological role was studied neonate rats developed due neuronal damage after receiving subcutaneous capsaicin injections. Treatment protected these against scratching behavior dermatitis. also restored density cutaneous nerve fibers inhibited histopathological changes are associated injection. Additionally, expression IL-1β, IL-4, IL-5, IL-10, IL-13 lesional skin decreased treatment. Based on data, propose inhibiting alleviated rat model relapsing reduction signaling cells fibers.