Nociceptive and inflammatory effects of subcutaneous TNF α
2000; Lippincott Williams & Wilkins; Volume: 85; Issue: 1 Linguagem: Inglês
10.1016/s0304-3959(99)00262-6
ISSN1872-6623
AutoresHeidi Junger, Linda S. Sorkin,
Tópico(s)Advancements in Transdermal Drug Delivery
ResumoTumor necrosis factor α (TNF) is a potent pro-inflammatory cytokine that produces pain and hyperalgesia following injection. Its algesic effects are due to sensitizing actions on nociceptive primary afferents and to the upregulation of other pro-inflammatory and algesic proteins. In anesthetized rats, we investigated the effect of subcutaneously injected TNF on background activity and mechanical sensitivity of C nociceptors of the sural nerve, as well as its effects on cutaneous plasma extravasation. TNF sensitized C nociceptors dose-dependently; the optimal dose (5 ng) lowered threshold in 66.7% of the tested fibers. This sensitization occurred within 30 min and could last for 2 or more hours. Injected TNF had no effect on Aβ mechanoreceptive fibers. In addition, TNF evoked ongoing activity in 14% of C nociceptors and caused significant and dose-related increases in vascular permeability in glabrous skin. Our data suggest that TNF released during disease or after tissue injury participates in the generation of hyperalgesia and inflammation.
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