Gabriel R, Lesauter J, Silver R, Garcia-España A, Witkovsky P
Department of General Zoology and Neurobiology, University of Pecs, H-7604 Pecs, Hungary.
J Comp Neurol. 2001 Oct 15;439(2):140-50. doi: 10.1002/cne.1338.
We studied the dependence of the expression of protein kinase C immunoreactivity (PKC-IR) in the rat retina on the light:dark (LD) cycle and on circadian rhythmicity in complete darkness (DD). Two anti-PKC alpha antibodies were employed: One, which we call PKCalphabeta recognized the hinge region; the other, here termed PKCalpha, recognized the regulatory region of the molecule. Western blots showed that both anti-PKC antibodies stained an identical single band at approximately 80 kD. The retinal neurons showing PKC-IR were rod bipolar cells and a variety of amacrine neurons. After 3 weeks on an LD cycle, PKCalphabeta-IR in both rod bipolar and certain amacrine cells manifested a clear rhythm with a peak at zeitgeber time (ZT) of 06-10 hours and a minimum at ZT 18. No rhythm in total PKC-IR was observed when using the PKCalpha antibody, but, at ZT 06-10 hours, rod bipolar axon terminals showed increased immunostaining. After 48 hours in DD, with either antibody, rod bipolar cells showed increased PKC-IR. The PKCalpha antibody alone revealed that, after 48 hours, AII amacrine neurons, which lacked PKC-IR in an LD cycle, manifested marked PKC-IR, which became stronger after 72 hours. Light administered early in the dark period greatly increased PKCalphabeta-IR in rod bipolar and some amacrine neurons. Our data indicate that light and darkness exert a strong regulatory influence on PKC synthesis, activation, and transport in retinal neurons.
我们研究了大鼠视网膜中蛋白激酶C免疫反应性（PKC-IR）的表达对光暗（LD）循环以及完全黑暗（DD）环境下昼夜节律的依赖性。我们使用了两种抗PKCα抗体：一种我们称为PKCalphabeta，识别铰链区；另一种在此称为PKCalpha，识别该分子的调节区。蛋白质印迹显示，两种抗PKC抗体均在约80 kD处染出一条相同的单带。显示PKC-IR的视网膜神经元为视杆双极细胞和多种无长突神经元。在LD循环3周后，视杆双极细胞和某些无长突细胞中的PKCalphabeta-IR表现出明显的节律，在授时因子时间（ZT）06-10小时达到峰值，在ZT 18时降至最低。使用PKCalpha抗体时未观察到总PKC-IR的节律，但在ZT 06-10小时，视杆双极轴突终末的免疫染色增强。在DD环境中48小时后，使用任何一种抗体，视杆双极细胞的PKC-IR均增加。单独使用PKCalpha抗体显示，在48小时后，在LD循环中缺乏PKC-IR的AII无长突神经元表现出明显的PKC-IR，在72小时后变得更强。在黑暗期早期给予光照可显著增加视杆双极细胞和一些无长突神经元中的PKCalphabeta-IR。我们的数据表明，光和暗对视网膜神经元中PKC的合成、激活和转运具有强大的调节作用。
