Interleukin-1 beta enhances capsaicin-induced neurogenic vasodilatation in the rat skin.
1. This study examined the effect of interleukin-1 beta (IL-1 beta) on the capsaicin-induced increase in cutaneous blood flow of anaesthetized rats as measured by laser Doppler flowmetry. 2. The substances were administered by intraplantar subcutaneous injection of 10 microliters-volumes, saline being injected into one hindpaw and IL-1 beta into the other. 3. IL-1 beta (0.5-500 pg) was without effect on blood flow on its own but dose-dependently enhanced the hyperaemic response to intraplantar capsaicin (0.3 microgram) up to 180% (P < 0.05) of the response seen in saline-treated paws. 4. Il-1 beta-(163-171), a fragment devoid of proinflammatory activity, failed to enhance capsaicin-induced hyperaemia when given at a dose of 50 pg. 5. Indomethacin (10 mg kg-1, i.p.) did not alter the capsaicin-induced vasodilatation but prevented IL-1 beta (50 pg) from augmenting the hyperaemic response to capsaicin. 6. The hyperaemia evoked by intraplantar calcitonin gene-related peptide (0.038-3.8 ng) was not altered by IL-1 beta (50 pg). 7. These data indicate that IL-1 beta enhances the cutaneous hyperaemic response to afferent nerve stimulation with capsaicin in a prostaglandin-dependent manner. This proinflammatory action of the cytokine appears to arise from sensitization of afferent nerve endings.
Department of Anaesthesiology, University of Würzburg, Germany.
M K
MK
Herbert
P
P
Holzer
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D006940:Hyperemia / Q000139:chemically induced; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000294:innervation*; D009475:Neurons, Afferent / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000098:blood supply*; D013268:Stimulation, Chemical; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology*
D007375:Interleukin-1; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; D007213:Indomethacin