Turnover of eye lens crystallines

Range Life time
Organism Human Homo sapiens
Reference Lynnerup N, Kjeldsen H, Heegaard S, Jacobsen C, Heinemeier J. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life. PLoS One. 2008 Jan 30 3(1):e1529. doi: 10.1371/journal.pone.0001529. p.3 left column 3rd paragraphPubMed ID18231610
Method "[Researchers] have exploited the radical variations of the atmospheric 14C content during the last 50 years to date the formation of the lens crystallines. The concentration of 14C in living tissues reflects the atmospheric 14C content at the time of growth. This is because cosmogenic 14C in the atmosphere reacts with oxygen to form carbon dioxide (CO2), which is incorporated by plants, and then ingested by animals...The nucleus of the human eye lens contains 10–15 mg tissue, corresponding to approximately 3– 5 mg carbon, which is sufficient to perform a high precision accelerator mass spectrometry (AMS)."
Comments "[Researchers'] results allow [them] to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. Such a life-long permanence of human tissue has hitherto only been described for dental enamel [refs 1, 11]."
Entered by Uri M
ID 109840