Electron spin resonance investigations of human retinal pigment epithelium melanosomes from young and old donors
| Autor: | V.B Ilyasova, Edward Wylegala, Barbara Bilińska, Tadeusz Wilczok, Mikhail A. Ostrovsky, Alexander E. Dontsov, Z Zawada, Barbara Pilawa, N. L. Sakina |
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| Rok vydání: | 2002 |
| Předmět: |
Adult
Adolescent Free Radicals Radical Analytical chemistry Analytical Chemistry law.invention Melanin Nuclear magnetic resonance law medicine Humans Irradiation Electron paramagnetic resonance Pigment Epithelium of Eye Instrumentation Spectroscopy Melanosome Retinal pigment epithelium Melanosomes Chemistry Relaxation (NMR) Age Factors Electron Spin Resonance Spectroscopy Middle Aged Single line Atomic and Molecular Physics and Optics medicine.anatomical_structure |
| Zdroj: | Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy. 58(10) |
| ISSN: | 1386-1425 |
| Popis: | Electron spin resonance (ESR) examinations of human retinal pigment epithelium melanosomes isolated from eyes of young and old donors were carried out. The examined ESR signal was a single line, which is characteristic for free radicals of eumelanin o-semiquinones. The content of free radicals related to melanosomes dry weight for samples from older donors (ages over 45 years) were higher than for sample from younger donors (between 14 and 22 years). Simultaneously, the content of free radicals calculated for one melanosome is constant and does not depend on age. The homogeneous broadening of the recorded ESR lines shows that there are no isolated spin packets in all investigated melanin samples. Slow spin-lattice (T1 approximately 10(-5) s) and fast spin-spin (T2 approximately 10(-8) s) relaxation processes occur in these samples. Saturation of the ESR lines at low microwave power was measured. High concentration of free radicals in melanosome samples was responsible for the fast spin-spin relaxation process. |
| Databáze: | OpenAIRE |
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