| Light elicits the release of docosahexaenoic acid from membrane phospholipids in the rat retina in vitro. | |
| | |
MedLine Citation:
|
PMID: 8943700 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Docosahexaenoic acid is the major polyunsaturated fatty acid in photoreceptor membrane phospholipids and is thought to be necessary for photoreceptor function. Docosahexaenoic acid may be metabolized to docosanoids or, by retroconversion, to eicosapentaenoic acid followed by lipoxygenation and synthesis of n-3 metabolites. In this study we investigated the time- and illuminance-dependent release of docosahexaenoic acid from photoreceptor phospholipids in the rat retina in vitro and the effects of the phospholipase A2 inhibitor, quinacrine, on this release. Isolated rat retinae were incubated in oxygenated Ringer-Bicarbonate-Glucose-Medium and labelled with [3H]docosahexaenoic acid for 180 min in darkness. The incorporation of [3H]docosahexaenoic acid into retinal phospholipids was monitored by thin-layer chromatography. The release of [3H]docosahexaenoic acid was determined under illuminances of 100, 500, 1000, 5000 and 10,000 lx for 10 min, illuminance durations of 0.25, 2, 5 and 10 min at 10,000 lx, and with the addition of 10 and 100 mumol quinacrine to the incubation medium at 10,000 lx for 10 min. Our results demonstrate a release of docosahexaenoic acid from retinal phospholipids that is finely tuned by light levels and exposure duration. The kinetics of the time dependent docosahexaenoic acid release and the effects of quinacrine suggest that this release is mediated in part by activation of phospholipase A2. The light-elicited docosahexaenoic acid release may serve as a protective measure against formation of prostaglandins by inhibiting cyclooxygenase and by promoting the synthesis of less potent leukotrienes of the 5-series via retroconversion to eicosapentaenoic acid and 5-lipoxygenation. |
| | |
Authors:
|
J J Reinboth; M Clausen; C E Remé |
Publication Detail:
|
Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Experimental eye research Volume: 63 ISSN: 0014-4835 ISO Abbreviation: Exp. Eye Res. Publication Date: 1996 Sep |
Date Detail:
|
Created Date: 1996-12-23 Completed Date: 1996-12-23 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0370707 Medline TA: Exp Eye Res Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 277-84 Citation Subset: IM |
Affiliation:
|
Universitätsspital Zürich, Augenklinik, Switzerland. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Analysis of Variance Animals Docosahexaenoic Acids / metabolism* Light* Male Membrane Lipids / metabolism* Phospholipases A / antagonists & inhibitors Phospholipases A2 Phospholipids / metabolism Quinacrine / pharmacology Rats Retina / metabolism* Rhodopsin / analysis |
| Chemical | |
Reg. No./Substance:
|
0/Membrane Lipids; 0/Phospholipids; 25167-62-8/Docosahexaenoic Acids; 83-89-6/Quinacrine; 9009-81-8/Rhodopsin; EC 3.1.1.-/Phospholipases A; EC 3.1.1.4/Phospholipases A2 |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Effect of epidermal growth factor on phosphatidylinositol 3-kinase activity in rabbit corneal epithe...
Next Document: Selective absence of cone outer segment beta 3-transducin immunoreactivity in hereditary cone degene...