The human liver retains great regenerative capacity even in the elderly and, regardless of the age of a person, the vast majority of cells in this organ are not more than three years old, say German scientists. In their research they used techniques used in archeology.
The cells of most tissues die after a while and new ones are created in their place. Natural renewal processes tend to weaken in old age, but this is not necessarily the case. As the latest research of scientists from Germany shows, the human liver is always less than three years old – both in young and seniors. More precisely, most of the cells in this organ do not exceed the age of three.
Cell division throughout life
The regenerative capacity of the liver is well documented scientifically, but German researchers have focused on determining whether this process is in any way dependent on the age of the person. They analyzed livers taken from 50 people who died between the ages of 20 and 84. It turned out that the age of the cells in these organs did not depend on the length of human life. In addition, the aging process did not affect the rate of tissue renewal.
Whether someone is 20 or 84 years old, their liver is less than three years old, says lead author Olaf Bergmann of the Dresden University of Technology descriptively.
The results of the interdisciplinary research have been published in the journal Cell Systems.
Protection against cancer
However, this does not mean that the liver does not change with age. Scientists have found that a small percentage of cells can live up to ten years. They are also structurally unique as they contain more genetic material.
“With age, the number of these cells increases,” explains Bergmann. “It could be a kind of protection mechanism against the build-up of harmful mutations,” he adds. And he emphasizes: “We need to find out if similar mechanisms are present in chronic liver diseases that can lead to malignant tumors.
A study on the verge of archeology
Determining the age of human cells is a complex task, and animal tissue research often produces results that cannot be directly translated into the human body. That is why the research team from the Dresden University of Technology used an unusual methodology.
Radiocarbon analysis, widely used by archaeologists, was used to determine the age of the tissues. This method has been slightly modified for the purposes of biology and is based on the measurement of the content of the radioactive carbon isotope 14C in cells.
During the tests of nuclear weapons in the 1950s, huge amounts of this element were released into the atmosphere, which began to decline over time. As research has shown, the level of 14The C in a cell’s DNA reflects the isotope content in the atmosphere at its birth. This relationship makes it possible to determine the age of a given organ.
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