alexa Influence of age, diabetes, and cataract on calcium, lipid-calcium, and protein-calcium relationships in human lenses.
Ophthalmology

Ophthalmology

Journal of Clinical & Experimental Ophthalmology

Author(s): Tang D, Borchman D, Yappert MC, Vrensen GF, Rasi V

Abstract Share this page

Abstract PURPOSE: Calcium is elevated in most cataractous human lenses and may contribute to cataractogenesis. In this study, age-related changes were examined in the total calcium content of clear human lenses and the binding of calcium to lens lipids and proteins. METHODS: Total lens calcium was determined by atomic absorption spectroscopy. Calcium binding was measured by light scattering and measurement of calcium by atomic absorption spectroscopy in bound and unbound fractions. RESULTS: The calcium content of clear human lenses decreased between 18 and 55 years of age and increased between 55 and 75 years, as well as in the presence of cataract. Total calcium levels in clear lenses from subjects with insulin-dependent diabetes did not differ from that in lenses of age-matched control subjects. In vitro binding studies have shown that lens lipids can bind nearly all the calcium present in the human lens. Age and cataract diminished the capacity of lens lipids to bind calcium. Calcium-induced light-scattering, measured in vitro for lens proteins, correlated with increasing age and cataract. CONCLUSIONS: The data support the hypothesis that increased intracellular calcium concentrations and a diminished capacity of lens lipids to bind to calcium initiate a cascade of events that culminates in increased light-scattering from lipids and especially proteins. Calcium binding to lipid membranes cannot directly contribute to light-scattering in cataractous lenses. It has been suggested that most of the diffusible calcium in the lens is in the intercellular spaces and that lens lipids in the outer leaflet of the bilayer bind to that calcium. If so, this could account for the 150-fold difference between free and bound calcium levels in the lens.
This article was published in Invest Ophthalmol Vis Sci and referenced in Journal of Clinical & Experimental Ophthalmology

Relevant Expert PPTs

Relevant Speaker PPTs

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords