Juzeniene Asta, Moan Johan
Dermatoendocrinol. 2012 Apr 1;4(2):109-17. doi: 10.4161/derm.20013.
Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in skin. However, several other pathways may exist for the action of ultraviolet (UV) radiation on humans as focused on in this review. One is induction of cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen. Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy). UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis. Furthermore, UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA-induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter. Finally, UV exposure may improve mood through the release of endorphins.
太阳辐射的大部分积极作用是通过紫外线B（UVB）诱导皮肤产生维生素D来介导的。然而，正如本综述所关注的，紫外线（UV）对人类的作用可能还存在其他几种途径。一种是诱导美容晒黑（即时色素沉着、持续性色素沉着和延迟性晒黑）。UVB诱导的延迟性晒黑（几天后皮肤中的黑色素增加）起到防晒作用。几种人类皮肤疾病，如牛皮癣、白癜风、特应性皮炎和局限性硬皮病，可以用太阳辐射（日光疗法）或人工紫外线辐射（光疗）进行治疗。紫外线照射可以独立于维生素D的合成来抑制多发性硬化症的临床症状。此外，紫外线会产生一氧化氮（NO），它可能会降低血压并总体上改善心血管健康。UVA诱导产生的NO也可能具有抗菌作用，此外，还可作为一种神经递质。最后，紫外线照射可能通过内啡肽的释放来改善情绪。
