Involvement of substance P in ultraviolet irradiation-induced inflammation in rat skin.
The possible involvement of substance P released from primary afferents in rat skin was investigated in cutaneous inflammation following ultraviolet (UV) irradiation. Recordings from c-fibres innervating the UV-exposed hindpaw skin showed long-lasting low-frequency (0.8-1.25 Hz) spontaneous activity. Spontaneously active c-fibres increased to constitute 35.3% of the total population 72 h after UV exposure. Immunohistochemical analysis of substance P-containing nerve fibres in hindpaw skin revealed a significant increase in substance P immunoreactivity 24 h after UV irradiation. Average length of substance P-immunolabelled nerve fibres was about two times higher in UV-exposed compared to control skin. UV-induced oedema was investigated in rat ears using an ear-swelling test. Intradermal injection of either peptide (Spantide) or nonpeptide (CP-96,345) substance P antagonists and epicutaneous application of CP-96,345 reduced UV-induced oedema significantly in the late phase of sunburn (> 12 h after UV exposure). The UV-induced increase in skin blood flow was investigated in hindpaw skin up to 72 h by the laser Doppler technique. Epicutaneous application of CP-96,345 reduced erythema significantly between 12 and 72 h after UV exposure. Thus, our findings suggest the involvement of neurogenic substance P as a proinflammatory mediator in the late phase of UV-induced cutaneous inflammation in rats.
Eschenfelder
C C
CC
II. Physiologisches Institut der Universität Heidelberg, Germany.
Benrath
J
J
Zimmermann
M
M
Gillardon
F
F
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology; D003872:Dermatitis / Q000209:etiology* / Q000378:metabolism*; D004487:Edema / Q000209:etiology; D004890:Erythema / Q000209:etiology; D006614:Hindlimb / Q000294:innervation; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000502:physiology; D011833:Radiation Injuries, Experimental / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D014466:Ultraviolet Rays
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001713:Biphenyl Compounds; D013373:Substance P; C042867:spantide; C066892:CP 96345