Mechanisms of photoreceptor death and survival in mammalian retina
| Autor: | Silvia Bisti, G. P. Lewis, Luigi Cervetto, Krisztina Valter-Kocsi, Nigel L. Barnett, Claudia Gargini, Juliani Maslim, Steven K. Fisher, Saul Merin, Jan Provis, Kyle Mervin, Yi Chu, Jonathan Stone, Jacob Pe'er, Felicity Bowers |
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| Rok vydání: | 1999 |
| Předmět: |
Retinal degeneration
Central nervous system Biology Retina chemistry.chemical_compound Retinal Diseases medicine Animals Humans Photoreceptor Cells Oxygen toxicity Age Factors Dystrophy Retinal detachment Retinal medicine.disease eye diseases Sensory Systems Ophthalmology medicine.anatomical_structure chemistry sense organs Neuroscience Retinal Dystrophies Forecasting |
| Zdroj: | Progress in retinal and eye research. 18(6) |
| ISSN: | 1350-9462 |
| Popis: | The mammalian retina, like the rest of the central nervous system, is highly stable and can maintain its structure and function for the full life of the individual, in humans for many decades. Photoreceptor dystrophies are instances of retinal instability. Many are precipitated by genetic mutations and scores of photoreceptor-lethal mutations have now been identified at the codon level. This review explores the factors which make the photoreceptor more vulnerable to small mutations of its proteins than any other cell of the body, and more vulnerable to environmental factors than any other retinal neurone. These factors include the highly specialised structure and function of the photoreceptors, their high appetite for energy, their self-protective mechanisms and the architecture of their energy supply from the choroidal circulation. Particularly important are the properties of the choroidal circulation, especially its fast flow of near-arterial blood and its inability to autoregulate. Mechanisms which make the retina stable and unstable are then reviewed in three different models of retinal degeneration, retinal detachment, photoreceptor dystrophy and light damage. A two stage model of the genesis of photoreceptor dystrophies is proposed, comprising an initial "depletion" stage caused by genetic or environmental insult and a second "late" stage during which oxygen toxicity damages and eventually destroys any photoreceptors which survive the initial depletion. It is a feature of the model that the second "late" stage of retinal dystrophies is driven by oxygen toxicity. The implications of these ideas for therapy of retinal dystrophies are discussed. |
| Databáze: | OpenAIRE |
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