Masuda K, Watanabe I, Unoki K, Ohba N, Muramatsu T
Department of Ophthalmology, Hamamatsu University, School of Medicine, Japan.
Invest Ophthalmol Vis Sci. 1995 Sep;36(10):2142-6.
To investigate whether and how survival-promoting agents rescue photoreceptor cell function and morphology from constant light damage, the authors recorded electroretinographic (ERG) responses and examined light micrographs of retinas in those rats given intravitreal injection of midkine (MK) and basic fibroblast growth factor (bFGF) before constant exposure.
Albino Sprague-Dawley rats were injected with MK, bFGF, or phosphate-buffered saline (PBS) 2 days before the onset of 1 week of constant light. ERG responses were recorded using white flash stimuli with the intensity range of 4 log units, followed by histologic examinations of retinas, including quantitative assessment of the outer nuclear layer thickness as an index of photoreceptor cell loss.
ERG responses were barely detectable in uninjected eyes after 1 week of constant light. On the other hand, distinct responses were recordable in eyes injected intravitreally with MK and bFGF, and the degree of ERG rescue in terms of the amplitude of b-wave was approximately 40% to 60% compared with normal eyes. Intravitreally injected PBS showed slight, but noticeable, preservation of ERG responses as well. Histologic examination revealed that MK and bFGF protected photoreceptors from light damage. A good correlation was found between anatomic rescue of photoreceptors as assessed by outer nuclear layer thickness and the functional rescue as defined by the magnitude of ERG responses.
Functional and anatomic rescue of photoreceptors in albino rats from constant light damage is achieved by prior intravitreal injection of MK and bFGF.
为了研究促生存因子是否以及如何从持续光照损伤中挽救光感受器细胞的功能和形态，作者记录了视网膜电图（ERG）反应，并检查了在持续光照前接受玻璃体内注射中期因子（MK）和碱性成纤维细胞生长因子（bFGF）的大鼠视网膜的光学显微镜图像。
在持续光照1周开始前2天，给白化Sprague-Dawley大鼠注射MK、bFGF或磷酸盐缓冲盐水（PBS）。使用强度范围为4个对数单位的白色闪光刺激记录ERG反应，随后对视网膜进行组织学检查，包括定量评估外核层厚度作为光感受器细胞丢失的指标。
持续光照1周后，未注射的眼睛几乎检测不到ERG反应。另一方面，在玻璃体内注射MK和bFGF的眼睛中可记录到明显的反应，与正常眼睛相比，b波振幅方面的ERG挽救程度约为40%至60%。玻璃体内注射PBS也显示出ERG反应有轻微但明显的保留。组织学检查显示，MK和bFGF保护光感受器免受光照损伤。通过外核层厚度评估的光感受器的解剖学挽救与由ERG反应幅度定义的功能挽救之间发现了良好的相关性。
通过玻璃体内预先注射MK和bFGF，可实现白化大鼠光感受器从持续光照损伤中的功能和解剖学挽救。
