Benshoff H M, Brainard G C, Rollag M D, Lynch G R
Department of Neurology, Jefferson Medical College, Philadelphia, PA 19107.
Brain Res. 1987 Sep 15;420(2):397-402. doi: 10.1016/0006-8993(87)91264-9.
The purpose of this study was to examine the effects of monochromatic visible and near-ultraviolet radiation (UV-A) on pineal melatonin suppression in the white-footed mouse, Peromyscus leucopus. To this end, mice were entrained to a daily cycle of 8 h of light and 16 h of darkness. During the night when pineal melatonin contents were high, mice were individually exposed for 5 min to specific wavelengths of monochromatic light (10 nm half-peak bandwidths). Control animals received the same handling conditions but no experimental exposure. Pineal glands were collected from animals 18 min after the 5 min experimental exposure and were later assayed for melatonin content. In groups of animals exposed to equal photon densities (2.64 X 10(15) photons/cm2) of either 320, 340, 360, 500, or 560 nm, mean pineal melatonin content was significantly suppressed as compared to the unexposed control animals. The 640 nm wavelength (red) at the same photon density did not suppress pineal melatonin. These experiments are the first to demonstrate light-induced suppression of pineal melatonin in Peromyscus leucopus. In addition, these data reveal a novel finding: the suppression of pineal melatonin content by ultraviolet wavelengths as low as 320 and 340 nm.
本研究的目的是检测单色可见光和近紫外辐射（UV-A）对白足鼠（白足鼠属）松果体褪黑素分泌抑制的影响。为此，将小鼠置于每天8小时光照和16小时黑暗的周期中。在夜间松果体褪黑素含量较高时，将小鼠分别暴露于特定波长的单色光（半峰带宽10纳米）下5分钟。对照动物接受相同的处理条件，但不进行实验暴露。在5分钟实验暴露后18分钟从动物身上采集松果体，随后测定褪黑素含量。在暴露于320、340、360、500或560纳米等光子密度相等（2.64×10¹⁵个光子/平方厘米）的动物组中，与未暴露的对照动物相比，松果体褪黑素平均含量显著降低。相同光子密度下的640纳米波长（红色）并未抑制松果体褪黑素。这些实验首次证明了光照对白足鼠松果体褪黑素的抑制作用。此外，这些数据揭示了一个新发现：低至320和340纳米的紫外波长可抑制松果体褪黑素含量。
