Retinal spreading depression induced by photoactivation: involvement of free radicals and potassium.
The threshold for spreading depression (SD) in chicken retina elicited by rose bengal photoactivation was raised by Trolox (water soluble vitamin E) suggesting the participation of reactive oxygen species in SD. The typical increases in K+ concentration associated with SD were preceded by small K+ oscillations that were more sensitive to photoactivation than was SD. It is hypothesised that all these phenomena could be accounted for by a free-radical mediated transient increase in membrane permeability and that this may be relevant to ischemic brain damage.
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002645:Chickens; D002839:Chromans / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology*; D005609:Free Radicals / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism / Q000503:physiopathology; D008278:Magnesium Sulfate / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D010507:Periodicity; D010777:Photochemistry; D011189:Potassium Chloride / Q000378:metabolism*; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D012395:Rose Bengal / Q000494:pharmacology*; D012413:Rubidium / Q000494:pharmacology