“Gerogenic Fractions In The Tritiated Rat”, 1971-07 (; similar):
A rat that had received tritiated acetate perinatally was killed at the age of 609 days, and was found to have retained substantial quantities of tritium in all organs examined. This study was focused on the liver, which—after a succession of extractions with a series of various solvents followed by catalytic hydrolysis at body temperature—yielded a residue that was-insoluble in a wide range of common solubilizing media. Treatment with hot mineral acid partially dissolved this residue and electrophoretic fractionation further led to 4 fractions of which a single fraction contained most of the tritium in the insoluble residue.
Our analyses showed that the insoluble residue contained a variety of common amino acids and a considerable amount of phosphorus. The solubilized fractions derived from the insoluble residue all contained substantial concentrations of pentose, deoxypentose, and phosphorus. They showed ultraviolet absorption spectra qualitatively similar to those of nucleic acids. From their chromatographic behavior on crosslinked dextran columns, all 4 solubilized fractions showed molecular weights greater than 5000. In addition, these fractions showed substantially greater resistance to hydrolytic degradation than do authentic RNA and DNA.
Taken together, this is interpreted as evidence that the gerogenic insoluble residue is composed of a highly crosslinked network of at least RNA, DNA and protein, which is stabilized by covalent cross-linkages of unusual stability.
Formation of these crosslinked structures could easily interfere with the function of certain critical molecules of RNA, DNA or other polymers, leading to impaired cell function and death.
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