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Proceedings Paper

Laser microbeams for DNA damage induction, optical tweezers for the search on blood pressure relaxing drugs: contributions to ageing research
Author(s): P. Grigaravicius; S. Monajembashi; M. Hoffmann; B. Altenberg; K. O. Greulich
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Paper Abstract

One essential cause of human ageing is the accumulation of DNA damages during lifetime. Experimental studies require quantitative induction of damages and techniques to visualize the subsequent DNA repair. A new technique, the "immuno fluorescent comet assay", is used to directly visualize DNA damages in the microscope. Using DNA repair proteins fluorescently labeled with green fluorescent protein, it could be shown that the repair of the most dangerous DNA double strand breaks starts with the inaccurate "non homologous end joining" pathway and only after 1 - 1 ½ minutes may switch to the more accurate "homologous recombination repair". One might suggest investigating whether centenarians use "homologous recombination repair" differently from those ageing at earlier years and speculate whether it is possible, for example by nutrition, to shift DNA repair to a better use of the error free pathway and thus promote healthy ageing. As a complementary technique optical tweezers, and particularly its variant "erythrocyte mediated force application", is used to simulate the effects of blood pressure on HUVEC cells representing the inner lining of human blood vessels. Stimulating one cell induces in the whole neighbourhood waves of calcium and nitric oxide, known to relax blood vessels. NIFEDIPINE and AMLODIPINE, both used as drugs in the therapy of high blood pressure, primarily a disease of the elderly, prolong the availability of nitric oxide. This partially explains their mode of action. In contrast, VERAPAMILE, also a blood pressure reducing drug, does not show this effect, indicating that obviously an alternative mechanism must be responsible for vessel relaxation.

Paper Details

Date Published: 20 August 2009
PDF: 11 pages
Proc. SPIE 7400, Optical Trapping and Optical Micromanipulation VI, 74000A (20 August 2009); doi: 10.1117/12.825616
Show Author Affiliations
P. Grigaravicius, Fritz Lipmann Institute (Germany)
S. Monajembashi, Fritz Lipmann Institute (Germany)
M. Hoffmann, Fritz Lipmann Institute (Germany)
B. Altenberg, European Molecular Biology Organization (Germany)
K. O. Greulich, Fritz Lipmann Institute (Germany)

Published in SPIE Proceedings Vol. 7400:
Optical Trapping and Optical Micromanipulation VI
Kishan Dholakia; Gabriel C. Spalding, Editor(s)

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