1 The effect of IL-1ra on response to intraplantar (i.pl.) injection of LPS
, carrageenin, bradykinin, TNF alpha, IL-1 beta, IL-beta, PGE(2) and dopami
ne was investigated in a model of mechanical hyperalgesia in rats.
2 IL-1ra inhibited hyperalgesic response to LPS, carrageenin, bradykinin, T
NF alpha, and IL-1 beta, but not responses to IL-8, PGE(2) and dopamine.
3 A sheep anti-rat IL-1ra serum potentiated response to LPS, carrageenin, b
radykinin, TNF alpha and IL-1 beta but not IL-8.
4 Carrageenin and LPS stimulated and production of immunoreactive TNF alpha
, IL-1 beta and IL-1ra in the skin of injected paws.
5 The inhibition by IL-1ra of the hyperalgesic response to carrageenin was
not affected by antibodies neutralizing IL-4 and IL-10.
6 In mice, IL-1ra inhibited the nociceptive response to i.p. injection of a
cetic acid.
7 These data suggest that IL-1ra, released at sites of inflammation, limits
inflammatory hyperalgesia. This effect is independent of (IL-1ra-induced)
IL-4 and IL-10 and appears to be the result of antagonism by IL-1ra of IL-1
beta-stimulated eicosanoid production.