Document Detail


Liquefaction of human vitreous in model aphakic eyes by 300-nm UV photolysis: monitoring liquefaction by fluorescence.
MedLine Citation:
PMID:  2384001     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
After the lens is removed in cataract surgery, the vitreous presumably receives all of the ambient 300-nm light that has filtered through the cornea. Using this model for aphakic eyes, we progressively irradiated intact vitreous samples of a 49-year-old human with 300-nm light and monitored changes in absorption, fluorescence, and circular dichroism (CD) properties. CD and fluorescence measurements of unirradiated vitreous samples showed a) a strong tryptophan fluorescence band of non-collagenous protein at 336 nm and a very weak band around 430 nm due to N-formylkynurenine (N-FK), a photoproduct of tryptophan, and b) a strong, negative CD band below 250 nm representing a composite spectrum of hyaluronic acid, collagen, and non-collagenous protein. Upon irradiation, the tryptophan emission band at 336 nm progressively decreased with time and the band maximum was concomitantly red-shifted; the N-FK fluorescence band at 430 nm, on the other hand, continually increased with the time of irradiation. A significant increase in the fluidity (liquefaction) of the vitreous gel also was noted upon irradiation, a change that was monitored successfully by measuring the progressive decrease in the polarization value of tryptophan fluorescence. The extent of liquefaction, measured spectroscopically, was found to be 40% upon irradiation for 10 hr. In addition, CD measurements indicated a partial loss in the secondary structure of the non-collagenous protein.
Authors:
N Ueno; B Chakrabarti
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Current eye research     Volume:  9     ISSN:  0271-3683     ISO Abbreviation:  Curr. Eye Res.     Publication Date:  1990 May 
Date Detail:
Created Date:  1990-09-20     Completed Date:  1990-09-20     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8104312     Medline TA:  Curr Eye Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  487-92     Citation Subset:  IM    
Affiliation:
Eye Research Institute, Boston, MA 02114.
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MeSH Terms
Descriptor/Qualifier:
Aphakia, Postcataract / pathology*
Circular Dichroism
Eye Proteins / metabolism
Female
Humans
Kynurenine / metabolism
Middle Aged
Spectrometry, Fluorescence
Tryptophan / metabolism
Ultraviolet Rays / adverse effects*
Viscosity
Vitreous Body / metabolism,  radiation effects*
Grant Support
ID/Acronym/Agency:
EY 05301/EY/NEI NIH HHS
Chemical
Reg. No./Substance:
0/Eye Proteins; 343-65-7/Kynurenine; 73-22-3/Tryptophan

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


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