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Abstract #24618 Published in IGR 11-4
The effects of acuter intraocular pressure elevation on melanopsin-containing retinal ganglion cells
Wang H; Hong J; Wang NChinese Ophthalmic Research 2009; 27: 558-562
Objective: Melanopsin-containing retinal ganglion cells (mcRGCs) play an important role in non-image-forming 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 null 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 (plus or minus) 2.24 vs 33.61 (plus or minus) 1.53, 3 353.02 (plus or minus) 114. 38/mm(2) vs 3 952.99 (plus or minus) 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 hypertension included the decrease and break of dendrites branch and dendrites field under the fluorescence microscope. Conclusion: Retina ischemia induced by high IOP results in the loss and structure change of mcRGCs. The mcRGCs of rat show more vulnerable to the acute IOP elevation than other RGCs. LA: Chinese
H. Wang. Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
