Document Detail

Effects of dark maintenance on retinal biochemistry and function during taurine depletion in the adult rat.
MedLine Citation:
PMID:  2487089     Owner:  NLM     Status:  MEDLINE    
Light dependence of the effects of taurine depletion on retinal function and biochemistry was examined in albino rats housed either in cyclic lighting or in continuous darkness. Measurements of retinal taurine, DNA, and rhodopsin contents, and electroretinogram amplitudes were made at weekly intervals. Naka-Rushton parameters were estimated for the b wave amplitude-intensity function. No significant effects of lighting regime were observed on retinal taurine levels in untreated rats, or on the time course or extent of taurine depletion in animals treated with guanidinoethyl sulfonate, an antagonist of taurine transport. In both lighting schemes, treatment led to a linear reduction of retinal taurine content which plateaued after 5-6 weeks at 50% of control despite continued treatment. DNA values did not differ among groups, whereas rhodopsin levels doubled in both groups of dark-maintained rats. For treated rats housed in cyclic lighting, the onset of electroretinogram deficits paralleled the loss of retinal taurine in the absence of changes in rhodopsin levels or cell death. Vmax was significantly reduced after 4 weeks of treatment. In contrast, for rats housed in continuous darkness, there were no significant differences in electroretinogram parameters between control and taurine-depleted rats until after 10-14 weeks of treatment. This implies that light exposure accelerates the appearance of functional changes associated with retinal taurine deficiency. The basis of the light dependence and the interpretation of related studies is discussed.
S E Cocker; N Lake
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Visual neuroscience     Volume:  3     ISSN:  0952-5238     ISO Abbreviation:  Vis. Neurosci.     Publication Date:  1989 Jul 
Date Detail:
Created Date:  1991-03-13     Completed Date:  1991-03-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8809466     Medline TA:  Vis Neurosci     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  33-8     Citation Subset:  IM    
Department of Physiology, McGill University, Canada.
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MeSH Terms
DNA / metabolism
Dark Adaptation*
Electroretinography / drug effects
Rats, Inbred Strains
Retina / metabolism*,  radiation effects
Rhodopsin / metabolism
Taurine / administration & dosage,  analogs & derivatives,  deficiency*
Reg. No./Substance:
107-35-7/Taurine; 543-18-0/taurocyamine; 9007-49-2/DNA; 9009-81-8/Rhodopsin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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