Department of Biochemistry and Molecular Pathology, Osaka City University Graduate School of Medicine, Osaka, Japan.
Photochem Photobiol. 2011 Jan-Feb;87(1):191-8. doi: 10.1111/j.1751-1097.2010.00822.x. Epub 2010 Nov 12.
We previously reported that topical irradiation of the eye by ultraviolet-B (UVB) activated hypothalamo-pituitary-adrenal axis (HPA-A) of the mouse to increase 3, 4-dihydroxyphenylalanine (DOPA)-positive melanocytes in the skin by an inducible nitric oxide synthase (iNOS)-dependent mechanism. This work demonstrates that irradiation of the eye by ultraviolet-A (UVA) specifically increased DOPA-positive cells in the mucosa of the jejunum and colon of C57BL/6J mice by some HPA- and iNOS-independent mechanism. UVA-induced increase in DOPA-positive cells in the intestine was inhibited by the administration of hexamethonium or prazosin plus propranolol, blockers for the sympathetic nervous system. UVA irradiation of the eye increased DOPA- and histidine decarboxylase (HDC)-positive cells in the intestinal mucosa of both C57BL/6J and WBB6F1/J mice but not in the mutant strain W/Wv of the latter that lack mast cells. UVA irradiation of the eye suppressed the intestinal peristalsis of control, hypophysectomized or iNOS(-/-) C57BL/6J mice by the mechanism that was inhibited by hexamethonium or prazosin plus propranolol. These observations suggest that UVA irradiation of the eye stimulated the sympathetic nervous system to increase the mucosal DOPA- and HDC-positive mast cells and suppressed the peristalsis of the small intestine of the mouse.
我们之前曾报道过，紫外线-B（UVB）照射眼部会激活小鼠的下丘脑-垂体-肾上腺轴（HPA-A），通过诱导型一氧化氮合酶（iNOS）依赖的机制增加皮肤中的 3,4-二羟苯丙氨酸（DOPA）阳性黑色素细胞。这项工作表明，紫外线-A（UVA）照射眼部会通过某种不依赖 HPA 和 iNOS 的机制特异性增加 C57BL/6J 小鼠空肠和结肠黏膜中的 DOPA 阳性细胞。UVA 诱导的肠道 DOPA 阳性细胞增加被六烃季铵或普萘洛尔加心得安阻断交感神经系统的药物所抑制。UVA 照射眼部会增加 C57BL/6J 和 WBB6F1/J 小鼠肠道黏膜中的 DOPA 和组氨酸脱羧酶（HDC）阳性细胞，但不会增加缺乏肥大细胞的后者的突变株 W/Wv。UVA 照射眼部通过被六烃季铵或普萘洛尔加心得安抑制的机制，抑制了对照、垂体切除或 iNOS(-/-) C57BL/6J 小鼠的肠道蠕动。这些观察结果表明，UVA 照射眼部刺激交感神经系统增加黏膜中的 DOPA 和 HDC 阳性肥大细胞，并抑制小鼠小肠的蠕动。
