Organisciak D T, Xie A, Wang H M, Jiang Y L, Darrow R M, Donoso L A
Department of Biochemistry, Wright State University, Dayton, OH 45435.
Exp Eye Res. 1991 Dec;53(6):773-9. doi: 10.1016/0014-4835(91)90113-s.
Long-term environmental light-mediated changes in visual cell transduction proteins were studied to assess the influence of rearing environment on their levels and their potential effects on intense light-induced retinal damage. The levels of rhodopsin, S-antigen and the alpha subunit of transducin were measured in whole eye detergent extracts, retinal homogenates or rod outer segments isolated from rats reared in weak cyclic light or darkness, and following a change in rearing environment. Rats changed from weak cyclic light to darkness had 22% more rhodopsin per eye than cyclic-light rats after 12-14 days in the new environment. Western trans-blot analysis of retinal proteins from these dark-maintained animals contained 65% higher levels of immunologically detectable alpha transducin; S-antigen levels were approximately 45% lower than in cyclic-light rats. In rats changed from the dark environment to weak cyclic light, rhodopsin levels decreased by 18% during a comparable period; retinal alpha transducin was 35% lower, S-antigen was 30% higher. At various times after the change in rearing environment, some rats were exposed to intense visible light to determine their susceptibility to retinal damage. Two weeks after an 8-hr exposure, cyclic-light reared rats had rhodopsin levels only 10% lower than control (2.1 nmol per eye). However, rhodopsin was 75% lower when cyclic-light rats were maintained in darkness for 2 weeks before intense light. For animals originally reared in darkness, rhodopsin was 78% lower following 8 hr of intense light, whereas only 30% rhodopsin loss occurred in dark-reared rats after previous maintenance for 2 weeks in weak cyclic-light.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了长期环境光介导的视觉细胞转导蛋白变化，以评估饲养环境对其水平的影响及其对强光诱导的视网膜损伤的潜在作用。在从弱循环光或黑暗环境饲养的大鼠中，以及在饲养环境改变后，对全眼去污剂提取物、视网膜匀浆或分离的视杆外段中的视紫红质、S抗原和转导蛋白α亚基水平进行了测量。从弱循环光环境转变为黑暗环境的大鼠，在新环境中饲养12 - 14天后，每只眼中视紫红质比循环光饲养的大鼠多22%。对这些在黑暗环境中饲养的动物的视网膜蛋白进行的Western转印分析显示，免疫可检测的α转导蛋白水平高65%；S抗原水平比循环光饲养的大鼠低约45%。从黑暗环境转变为弱循环光环境的大鼠，在相当一段时间内视紫红质水平下降了18%；视网膜α转导蛋白低35%，S抗原高30%。在饲养环境改变后的不同时间，一些大鼠暴露于强光下以确定它们对视网膜损伤的易感性。暴露8小时后两周，循环光饲养的大鼠视紫红质水平仅比对照低10%（每只眼2.1纳摩尔）。然而，当循环光饲养的大鼠在强光照射前在黑暗中饲养2周时，视紫红质降低了75%。对于最初在黑暗中饲养的动物，强光照射8小时后视紫红质降低了78%，而在弱循环光环境中饲养2周后的黑暗饲养大鼠中，视紫红质仅损失30%。（摘要截短至250字）
