Age-associated increase of free dolichol levels in mice.

Free dolichol levels were determined by high-performance liquid chromatography in liver, brain, heart, lung, testis and kidney of C57 B1/6 mice at 3, 6, 12 and 30 months of age. In all the tissues, free dolichol levels were increased with aging. The largest increase in dolichol was in testis and the smallest increase was in the liver. Among the various tissues, aging testis and kidney showed high levels of free dolichol, and represented more than twice the level of dolichol in brain. The major dolichols among the various tissues were of the 17, 18, 19 and 20 isoprene unit containing types and the proportions were unaffected by aging. Tissues such as brain and testis showed a tendency toward high proportions of longer-chain dolichols , whereas lung and heart showed high proportions of shorter-chain dolichols . This study shows that the age-associated increase in dolichol levels is a general phenomenon and the increases vary widely with tissues.