Programa de Pós-Graduação em Ciências Morfológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro - UFRJ, 21941-590 Rio de Janeiro, RJ, Brazil.
Comp Biochem Physiol C Toxicol Pharmacol. 2011 Nov;154(4):427-34. doi: 10.1016/j.cbpc.2011.08.002. Epub 2011 Aug 10.
The first and main target-structure of ultraviolet (UV) radiation in animals is the body surface, including the skin and eyes. Here, we investigated cell damage in the visual system of the crab Neohelice granulata acclimated to constant light and exposed to UVA or UVB at 12:00 h for 30 min. The reactive oxygen species (ROS) production, antioxidant capacity against peroxyl radicals (ACAP), lipid peroxidation (LPO) damage, catalase (CAT) activity, and the melatonin immunohistochemical reactivity in the eyestalks were evaluated. The animals that received melatonin and were exposed to UVA and UVB radiation showed a decreased ROS concentration (p<0.05).The ACAP test showed a decrease (p<0.05) in their values when the animals received 2 pmol/crab of melatonin (physiological dose) before the exposure to UVA radiation. The animals exposed to UVB radiation after receiving the same dose of melatonin showed an increase (p<0.05) in the ACAP test compared with the animals exposed to UVB radiation after receiving only crab physiological saline. The CAT activity increased (p<0.05) in the animals that received melatonin and were exposed to UVA and UVB radiation. Animals exposed to UVA and UVB displayed an increase (p<0.05) in the LPO levels, whereas animals treated with melatonin showed lower (p<0.05) LPO levels when irradiated. The results indicate that the specific oxidative parameters altered by UV radiation can be modulated by a physiological dose of melatonin. Moreover, the melatonin regularly produced by virtually all eyestalk cells suggests that it may function to modulate the noxious effects of radiation, at least in the crab N. granulata.
紫外线 (UV) 辐射在动物体内的首要和主要靶标结构是体表，包括皮肤和眼睛。在这里，我们研究了适应持续光照并在 12:00 暴露于 UVA 或 UVB 30 分钟的蟹 Neohelice granulata 视觉系统中的细胞损伤。评估了眼柄中的活性氧 (ROS) 产生、抗过氧自由基能力 (ACAP)、脂质过氧化 (LPO) 损伤、过氧化氢酶 (CAT) 活性和褪黑素免疫组织化学反应。接受褪黑素并暴露于 UVA 和 UVB 辐射的动物显示 ROS 浓度降低 (p<0.05)。当动物在暴露于 UVA 辐射之前接受 2 pmol/只蟹的褪黑素（生理剂量）时，ACAP 测试显示其值降低 (p<0.05)。与仅接受蟹生理盐水的动物相比，接受相同剂量褪黑素后暴露于 UVB 辐射的动物的 ACAP 测试显示出增加 (p<0.05)。暴露于 UVA 和 UVB 辐射的动物的 CAT 活性增加 (p<0.05)。暴露于 UVA 和 UVB 的动物的 LPO 水平增加 (p<0.05)，而用褪黑素处理的动物的 LPO 水平较低 (p<0.05) 当被辐射时。结果表明，UV 辐射改变的特定氧化参数可以被生理剂量的褪黑素调节。此外，几乎所有眼柄细胞都定期产生褪黑素，这表明它可能起到调节辐射的有害作用的作用，至少在蟹 N. granulata 中是这样。
