Sex-related differences in SLIGRL-induced pruritus in mice.
OBJECTIVE
Pruritus is a common symptom of skin diseases, and is associated with impaired sleep quality and a considerable reduction in the patient's quality of life. Recently, it was reported that there are sex-specific differences in scratching behavior in chronic pruritus patients. Namely, female chronic pruritus patients scratch more and have significantly more scratch lesions than male patients. However, few animal studies have examined sex-related differences in scratching behavior. Thus, the present work investigated sex-related differences in animal pruritus using pruritogens, which are often used to create experimental animal models of itching.


METHODS
Acute pruritus was induced in ICR mice by a single intradermal injection of histamine, 4-methylhistamine, serotonin, compound 48/80, substance P (SP), or the proteinase-activated receptor-2 (PAR-2)-activating peptide SLIGRL-NH2. Chronic pruritus was induced by 5 weeks of the repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB) to BALB/c mice.


RESULTS
Female mice showed significantly higher scratching counts in SLIGRL-NH2-induced pruritus than male mice. Conversely, there was no obvious sex-related difference in scratching behavior for the other pruritogens examined.


CONCLUSIONS
These results indicate that sex-related differences may exist in the pruritogen-responsive neurons that transmit the itch signal induced by SLIGRL-NH2, but not by histamine or 5-HT.
Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan. Electronic address: yamaura@chiba-u.jp.
Katsunori
K
Yamaura
Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
Ayana
A
Tomono
Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
Eriko
E
Suwa
Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
Koichi
K
Ueno
D000208:Acute Disease; D000818:Animals; D001522:Behavior, Animal; D002908:Chronic Disease; D004195:Disease Models, Animal; D005260:Female; D006632:Histamine / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D009842:Oligopeptides / Q000494:pharmacology*; D011537:Pruritus / Q000503:physiopathology*; D012701:Serotonin / Q000494:pharmacology; D012737:Sex Factors
D009842:Oligopeptides; C112356:seryl-leucyl-isoleucyl-glycyl--arginyl-leucinamide; D012701:Serotonin; D006632:Histamine
Proteinase-activated receptor-2; Pruritus; Scratching behavior; Sex-related differences; Substance P