Age-related changes in the molecular weight of hyaluronic acid from rat skin

Age-related changes in the molecular weight of hyaluronic acid from the skin of rats was studied using fetuses, newborn animals and rats 1, 2, 3, 4, 13, 26 and 52 weeks of age. Average values of the molecular weight of hyaluronic acid varied with age in three phases: 39 X 10(4) in fetuses and up to the age of one week, 55 X 10(4) in individuals aged to 26 weeks and 87 X 10(4) in individuals 52 weeks of age. The distribution of molecular weight was quite different between 4 weeks and 52 weeks of age. At 4 weeks of age, the molecular weight of hyaluronic acid was widely distributed, ranging from 18 X 10(4) to 79 X 10(4), while that from 52-week-old individuals was very high with a distribution ranging from 92 X 10(4) to 119 X 10(4).