Topical capsaicin pretreatment inhibits axon reflex vasodilatation caused by somatostatin and vasoactive intestinal polypeptide in human skin.
1 Wheal and flare reactions are described following intradermal injections of somatostatin, vasoactive intestinal polypeptide, substance P and histamine in normal human forearm skin. Bombesin failed to produce a significant wheal and flare.2 Pretreatment of skin with capsaicin in all cases dramatically inhibited the flare but not the wheal. This result is in accord with the hypothesis that capsaicin blocks the effector side of the axon reflex, perhaps by depleting nerve terminals of vasodilatory peptide(s).
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D001369:Axons / Q000187:drug effects*; D001839:Bombesin / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005768:Gastrointestinal Hormones / Q000037:antagonists & inhibitors*; D006801:Humans; D012018:Reflex / Q000187:drug effects; D012867:Skin / Q000098:blood supply / Q000187:drug effects*; D012882:Skin Tests; D013004:Somatostatin / Q000037:antagonists & inhibitors*; D014660:Vasoactive Intestinal Peptide / Q000037:antagonists & inhibitors*; D014664:Vasodilation / Q000187:drug effects*; D014666:Vasomotor System / Q000187:drug effects
D005231:Fatty Acids, Unsaturated; D005768:Gastrointestinal Hormones; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D001839:Bombesin; D002211:Capsaicin