Hiramoto Keiichi, Jikumaru Mika, Yamate Yurika, Sato Eisuke F, Inoue Masayasu
Department of Biochemistry and Molecular Pathology, Osaka City University Medical School, 1-4-3 Asahimachi, Abeno, Osaka, Japan.
Arch Dermatol Res. 2009 Mar;301(3):239-44. doi: 10.1007/s00403-008-0926-2. Epub 2009 Jan 30.
Irradiation by ultraviolet A (UVA) initiates the suppression of skin contact hypersensitivity. However, the change in the whole body immunity by UVA irradiation of the eye is still unknown. The mice used in this study were separated into four groups namely: a control, UVA irradiation of the eye, UVA irradiation of the ear, UVA irradiation of the eye + a glucocorticoid receptor antagonist (RU-486) administrated, UVA irradiation of the eye with an adrenalectomy and non-irradiation + cortisol administrated groups. The eye or ear was locally exposed to UVA after covering the remaining body surface with aluminum foil at a dose of 110 kJ/m(2) using a FL20SBLB-A lamp. Plasma adrenocorticotropic hormone, cortisol, and interleukin-10 (IL-10) content increased by UVA irradiation of the eye. In addition, UVA irradiation of the eye induced down-regulation of the epidermal Langerhans cells in the ear and the up-regulation of the mucosal immunoglobulin A (IgA) in the intestine. However, the changes in the epidermal Langerhans cells and mucosal IgA of UVA irradiation of the eye are not induced either by the RU-486 treatment or an adrenalectomy. These results clearly indicate that the signal evoked by UVA irradiation of the eye, through the hypothalamo-pituitary-adrenal pathway, up-regulated the production of glucocorticosterone. This hormone controls immunity, and the possibility that it performed a living body defense for UVA exposure was thus suggested.
紫外线A（UVA）照射可引发皮肤接触超敏反应的抑制。然而，眼部UVA照射对全身免疫的影响仍不清楚。本研究中使用的小鼠被分为四组，即：对照组、眼部UVA照射组、耳部UVA照射组、眼部UVA照射 + 给予糖皮质激素受体拮抗剂（RU - 486）组、眼部UVA照射并肾上腺切除组以及未照射 + 给予皮质醇组。用铝箔覆盖小鼠身体其余部位后，使用FL20SBLB - A灯以110 kJ/m²的剂量对眼部或耳部进行局部UVA照射。眼部UVA照射可使血浆促肾上腺皮质激素、皮质醇和白细胞介素 - 10（IL - 10）含量增加。此外，眼部UVA照射可导致耳部表皮朗格汉斯细胞下调以及肠道黏膜免疫球蛋白A（IgA）上调。然而，RU - 486处理或肾上腺切除均未诱导眼部UVA照射所引起的耳部表皮朗格汉斯细胞和黏膜IgA的变化。这些结果清楚地表明，眼部UVA照射通过下丘脑 - 垂体 - 肾上腺途径引发的信号上调了糖皮质激素的产生。这种激素控制免疫，因此提示其可能对UVA暴露起到了机体防御作用。
