An increase in the growth of hair associated with hyperinnervation of the underlying vessels in rabbit skin.
The localization of sympathetic nerves was studied histochemically in specimens of abdominal free flaps or revascularized graft and anastomosed epigastric arteries (i.e. the cut epigastric artery was resutured) from the operated and contralateral sides of rabbits, compared to controls. In the abdominal skin from control animals, noradrenaline-containing nerves were seen around blood vessels, hair follicles, sweat glands and dermis. In the free flaps, no noradrenaline-containing nerves were present after day 7. However, on the contralateral side, there was an increase in the density of these nerves by day 30, compared with controls. In the epigastric artery, noradrenaline-containing nerves were confined to the adventitial-medial border in control animals and were absent from the anastomosed epigastric arteries, but on the contralateral side they penetrated a third of the medial wall by day 15. Concomitantly, there was excessive growth of hair on the contralateral side. Understanding of the mechanism involved may be of importance in solving the problems associated with hair loss.
Crowe
R
R
Department of Anatomy and Developmental Biology, University College London, UK.
Mitsou
J
J
McGrouther
D A
DA
Burnstock
G
G
D000005:Abdomen / Q000098:blood supply; D000818:Animals; D001808:Blood Vessels / Q000294:innervation*; D006197:Hair / Q000254:growth & development*; D009638:Norepinephrine / Q000032:analysis; D011817:Rabbits; D012867:Skin / Q000294:innervation*; D012879:Skin Physiological Phenomena; D013524:Surgical Flaps; D013564:Sympathetic Nervous System / Q000737:chemistry / Q000473:pathology / Q000502:physiology*; D014945:Wound Healing
D009638:Norepinephrine