Ayala M N, Michael R, Söderberg P G
St. Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
Invest Ophthalmol Vis Sci. 2000 Oct;41(11):3539-43.
It is believed that for a certain ultraviolet radiation (UVR) exposure, the biologic effect depends on the product of irradiance and exposure time (the reciprocity Bunsen-Roscoe law). The purpose of this study was to investigate the validity of the reciprocity law for UVR-induced cataract.
Two experiments were conducted. In the first one, 100 Sprague-Dawley rats were exposed to UVR divided into five groups according to exposure time: 7.5, 15, 30, 60, and 120 minutes. In the second experiment, 80 Sprague-Dawley rats were exposed to UVR divided into four groups according to exposure time: 5, 7.5, 11, and 15 minutes. All the animals were unilaterally exposed to the same dose of UVR (8 kJ/m(2)) in the 300-nm wavelength region. One week after exposure both lenses were removed to measure the intensity of forward light scattering and for microphotography. Groups were compared by evaluating the difference between exposed and nonexposed eyes.
The group exposed to UVR for 5 minutes had the lowest intensity of forward light scattering. The highest intensity of forward light scattering was found in the group that was exposed for 15 minutes. With longer exposure intervals, the intensity of forward light scattering decreased as the exposure time increased. No difference in intensity of forward light scattering was found between the groups exposed for 60 and 120 minutes. CONCLUSIONS; Exposure time strongly influenced cataract formation after low-dose UVR. In this model of UVR-induced cataract, the photochemical reciprocity law was modulated by a biologic response.
人们认为，对于一定的紫外线辐射（UVR）暴露，生物学效应取决于辐照度和暴露时间的乘积（互易性本生 - 罗斯科定律）。本研究的目的是调查互易定律对于UVR诱导白内障的有效性。
进行了两项实验。在第一项实验中，将100只斯普拉格 - 道利大鼠暴露于UVR，根据暴露时间分为五组：7.5、15、30、60和120分钟。在第二项实验中，将80只斯普拉格 - 道利大鼠暴露于UVR，根据暴露时间分为四组：5、7.5、11和15分钟。所有动物均在300纳米波长区域单侧暴露于相同剂量的UVR（8 kJ/m²）。暴露一周后，取出双侧晶状体以测量前向光散射强度并进行显微摄影。通过评估暴露眼和未暴露眼之间的差异对各组进行比较。
暴露于UVR 5分钟的组前向光散射强度最低。暴露15分钟的组前向光散射强度最高。随着暴露间隔时间延长，前向光散射强度随着暴露时间增加而降低。暴露60分钟和120分钟的组之间在前向光散射强度上未发现差异。结论：低剂量UVR暴露后，暴露时间对白内障形成有强烈影响。在这个UVR诱导白内障的模型中，光化学互易定律受到生物学反应的调节。
