Ann Dermatol.  2001 Mar;13(1):16-21. 10.5021/ad.2001.13.1.16.

Change of Inducible Nitric Oxide Synthase Expression by Ultraviolet B Irradiation on the Skin of a Rat

• Yoo HC
• Lee HW
• Lee JE
• Lee JB
• Won YH
• Lee SC

• KMID: 2163854
• DOI: http://doi.org/10.5021/ad.2001.13.1.16

Abstract

BACKGROUND
Nitric oxide synthase (NOS) is known to mediate ultraviolet B (UVB)-induced skin inflammation However, there is still ambiguity as to which NOS isotype mediates the process in vivo. Furthermore, contradictory results have been reported on which cell types respond to UVB irradiation in vitro.
OBJECTIVE
This study was performed to evaluate the change of inducible NOS (iNOS) expression in vivo as a result of UVB radiation on the skin of a rat. METHOD: To examine the time-course change in iNOS expression in the rat skin, the rats were exposed to 400 ml/cm2 of UVB radiation, and skin samples were taken at various time intervals up to 48 h. iNOS expression on the skin of a rat was evaluated by both Western blot analysis and immunohistochemical staining.
RESULTS
From Western blot analysis, UVB irradiation induced inducible NOS (iNOS) expression in the epidermis at 12-48 h postirradiation with a peak expression at 24 h. Immunohistochemical staining revealed that UVB-induced iNOS expression was localized to the epidermis and infiltrating inflammatory cells in the upper dermis of the rat.
CONCLUSION
iNOS was induced by UVB irradiation on the skin of a rat, mainly in the epidermis. Therefore, iNOS is supposed to be one of the major mediators with regard to inducing an inflammatory response in UVB-irradiated rat skin in vivo.

Keyword

iNOS

MeSH Terms

Animals
Blotting, Western
Dermis
Epidermis
Inflammation
Nitric Oxide Synthase
Nitric Oxide Synthase Type II*
Rats*
Skin*
Nitric Oxide Synthase
Nitric Oxide Synthase Type II