Foot shock stress prolongs the telogen stage of the spontaneous hair cycle in a non-depilated mouse model.
BACKGROUND
There is an increasing evidence to indicate that stress can influence skin disease and cutaneous functions. Previous studies have shown that stress alters the murine hair cycle; however, these studies have been carried out by using mouse models in which the hair cycle is forcibly synchronized after depilation.


OBJECTIVE
To examine whether foot shock stress (FS) changes the spontaneous hair cycle in a non-depilated animal model, and to evaluate the role of mast cells and substance P (SP) in the influence of stress on the hair cycle.


METHODS
Changes in the spontaneous hair cycle and the inhibitory effects of a specific SP NK1 receptor antagonist were examined in non-depilated mice during 3-4 weeks of FS.


RESULTS
Foot shock stress prolonged the telogen stage of the hair cycle and delayed the induction of the subsequent anagen stage in the animal model. FS caused an increase in the ratio of de-granulated mast cells in the skin, an increase in the number of TUNEL-positive cells, and a decrease in the number of Ki67-positive cells. The NK1 receptor antagonist, WIN 62577, inhibited these stress responses.


CONCLUSIONS
Our results strongly support previous work, demonstrating that stress alters active hair-cycling in vivo through the action of SP.
Katayama
Mirei
M
Department of Dermatology, Nippon Medical School, Tokyo, Japan.
Aoki
Eri
E
Suzuki
Hidenori
H
Kawana
Seiji
S
D000505:Alopecia / Q000209:etiology; D000736:Androstenes / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001562:Benzimidazoles / Q000494:pharmacology; D015550:Cell Degranulation / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D004597:Electroshock; D006197:Hair / Q000166:cytology / Q000473:pathology / Q000503:physiopathology*; D018859:Hair Follicle / Q000166:cytology; D020287:In Situ Nick-End Labeling; D015603:Keratinocytes / Q000502:physiology; D019394:Ki-67 Antigen / Q000502:physiology; D008407:Mast Cells / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D064729:Neurokinin-1 Receptor Antagonists; D012867:Skin / Q000473:pathology; D018709:Statistics, Nonparametric; D013312:Stress, Physiological / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D013373:Substance P / Q000037:antagonists & inhibitors / Q000502:physiology*
D000736:Androstenes; D001562:Benzimidazoles; D019394:Ki-67 Antigen; D064729:Neurokinin-1 Receptor Antagonists; C086110:WIN 62577; D013373:Substance P