ovalbumin and phenylbenzoquinone

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.

Topics: Acetic Acid; Animals; Benzoquinones; Homozygote; Hot Temperature; Hyperalgesia; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Interleukins; Mice; Mice, Inbred BALB C; Motor Activity; Nociception; Nociceptive Pain; Ovalbumin; Pain Measurement; Receptors, Interleukin; Rotarod Performance Test; Signal Transduction