急性高眼压对大鼠包含黑视素的视网膜神经节细胞的影响

目的观察高眼压是否会对大鼠包含黑视素的视网膜神经节细胞（mcRGCs）产生损伤。方法利用前房灌注制作急性高眼压诱导的视网膜缺血再灌注模型，利用免疫组织化学法显示mcRGCs及普通神经节细胞，观察其密度的改变。结果急性高眼压后7d，mcRGCs和其他神经节细胞的密度较正常组明显下降，密度分别为（23．36±2．22）、（33．36±1．53）、（3353．02±114．38）个／mm^2和（3952．99±19．92）个／mm^2，存活率分别为67．03％和84．82％。mcRGCs2级及以上的细胞树突分支减少，树突野范围变小，部分损伤严重的细胞只有胞体着色。结论缺血再灌注可以造成大鼠mcRGCs密度下降以及树突分支结构的改变，此类细胞的损伤程度重于其他的神经节细胞的损伤程度。

The effects of acuter intraocular pressure elevation on melanopsin-containing retinal ganglion cells

Objective Melanopsin-containing retinal ganglion cells （mcRGCs） play an important role in non-imageforming visual function. Researches showed that retinal ischemia/reperfusion induced by acute ocular hypertention results in the decrease of total RGCs. But whether mcRGCs are affected is below clear. This study was to investigate the effects of acute intraocular pressure （IOP） elevation on mcRGCs in rats. Methods A transient ischemic insult was induced in retinas of 6 male Wistar rats by elevating the IOP through the anterior chamber infusion of normal saline solution （NS） in the height of 133 cm（ with the pressure 13.3 kPa）for 75 minutes in the right eyes to create the retinal ischemia, and then the IOP was recovered for the reperfusion of retina. In the left eyes, puncture of anterior chamber without NS infusion was performed as control. Seven days later,the eyeballs were enucleated and retinas were isolated. The cell bodies, dendrites, and axons of mRGCs were detected with an antibody against melanospin by free floating immunohistochemistry. Stacked images of scanning laser microscopy allowed view of all the processes by putting the images at different focal planes into one image. Other RGCs on the same retina were labeled with 4＇ ,6＇-diamidino-2-phenylindole（DAPI）. mcRGCs were counted at a magnification of 200 x and the average mcRGCs and other RGCs density were calculated under the scanning laser microscopy. The use of animals followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results Compared with the left eyes,the densities of both mcRGCs and other RGCs in the right eyes were reduced on 7 days after acute IOP elevation（ 23.48 ± 2.24 vs 33.61 ± 1.53,3 353.02 ±114. 38/mm^2 vs 3 952.99 ± 19.92/mm^2, respectively ）, showing statistically significant differences between them （ t = - 6. 20, P = 0. 003; t = - 4. 474, P = 0. 011 ）. The structure alteration of RGCs following the acute ocular hyperten