Original articleRetinal Ganglion Cell Death Induced by Retinal Ischemia: Neuroprotective Effects of Two Alpha-2 Agonists
Section snippets
Methods
Adult Sprague-Dawley rats were anesthetized with 7% chloral hydrate in saline administered intraperitoneally (IP; 0.42 mg/g body weight). The RGC population was retrogradely labelled from the superior colliculi (SCi) with the fluorescent tracer fluorogold (FG) following already described protocols.14, 19, 20 In brief, the midbrain was exposed, the pia overlying both SCi was removed and a small piece of gelatin sponge (Spongostan® Film, Ferrosan, Denmark) soaked in a solution of 3% FG and 10%
Results
The main findings of this study can be summarized as follows. 1) Seven days after 90 min of retinal ischemia, there is loss of approximately 47% of the RGC population. Between day 7 and day 21 there is an additional delayed loss of 15% of the RGC population. 2) Systemic or topical pretreatment with a single dose of the two α-2 agonists protects RGCs from ischemia-induced cell death. These agents have a potent neuroprotective effect and may prevent the early as well as the protracted phase of
Discussion
Neuroprotection implies prevention of injury- or disease-induced neuronal death. This is a relatively recent term that has evolved over the last years and is based on basic research that has been conducted to understand the process of neuronal death both during development and after injury. It is well established that a common mechanism of cell death during development of the central nervous system, responsible for the death of approximately 50% of embryonic neurons, is apoptosis. This type of
Acknowledgements
The authors thank Dr. Larry Wheeler for helpful discussions during the course of this work, and Dr. Marcelino Avilés for help with the photography.
Supported in part by The Spanish Fondo de Investigación Sanitaria (98/0341; 99/1090); The Fundación Séneca de la Comunidad Autónoma de Murcia (PB18FS97), and; an unrestricted grant from Allergan Inc. (USA).
The authors have no proprietary or commercial interest in any product or concept discussed in this article.
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