Department of Anatomy, Histology and Embryology, Shanghai Medical School, Fudan University, 200032 Shanghai, China.
Brain Res Bull. 2010 Apr 5;81(6):617-24. doi: 10.1016/j.brainresbull.2010.01.012. Epub 2010 Jan 25.
Ouabain is both a cardiac glycoside used in therapy of congestive heart failure and an endogenous steroid hormone. It specifically binds to Na(+), K(+)-ATPase (NKA) and blocks its activity. Overdose of ouabain induces retinal damage. In different species ouabain-induced retinal degeneration affects different cell types. In fish and rabbit ouabain induces retinal cell death preferentially in the ganglion cell layer and outer photoreceptor segments respectively. In rats, the pattern of NKA expression has been studied with most detail among retinal neurons. In addition, ouabain selectively destroyed some types of neurons in rodents. However, ouabain-sensitive retinal neurons remain unclear in rats. We show here that injection of ouabain into the rat vitreous body induced dramatic cell death in the inner nuclear layer (INL). The cell death was time- and dose-dependent. Ouabain-induced dying cells in the INL were TUNEL-positive. Immunohistochemistry analysis revealed that there was a significant decrease in the number of calbindin D-28K- and syntaxin-1-positive horizontal and amacrine cells in the INL of ouabain-treated rat retinas. Thus our results revealed that the horizontal and amacrine cells are the most sensitive cell types to ouabain in the retina of Sprague-Dawley rat.
哇巴因既是一种用于充血性心力衰竭治疗的强心苷，也是一种内源性甾体激素。它特异性地与 Na(+)，K(+)-ATP 酶 (NKA) 结合并阻断其活性。哇巴因过量会引起视网膜损伤。在不同物种中，哇巴因诱导的视网膜变性会影响不同的细胞类型。在鱼类和兔中，哇巴因分别优先诱导神经节细胞层和外光感受器节段的视网膜细胞死亡。在大鼠中，NKA 表达模式在视网膜神经元中研究得最为详细。此外，哇巴因在啮齿动物中选择性地破坏了某些类型的神经元。然而，哇巴因敏感的视网膜神经元在大鼠中仍不清楚。我们在这里表明，将哇巴因注入大鼠玻璃体可引起内核层 (INL) 中明显的细胞死亡。细胞死亡与时间和剂量有关。在 INL 中，哇巴因诱导的死亡细胞呈 TUNEL 阳性。免疫组织化学分析显示，哇巴因处理的大鼠视网膜 INL 中的 calbindin D-28K 和 syntaxin-1 阳性水平细胞和无长突细胞数量显著减少。因此，我们的结果表明，水平细胞和无长突细胞是 Sprague-Dawley 大鼠视网膜中对哇巴因最敏感的细胞类型。
