Elastin metabolism in rodent lung

Data from the in vivo incorporation of ³H]valine into fractions of elastin obtained from rat or mouse lung suggest that postnatal lung elastin synthesis occurs predominantly in the first 1 to 2 weeks of life. Very little ³H]valine was incorporated into lung elastin obtained from adult animals. When lung elastin from neonatal mice was radiochemically labelled with ¹⁴C]lysine as a single pulse, it was observed that the specific activity of the elastin expressed as the total dpm values as ¹⁴C per mg was not significantly altered over a 6 month period. Elastin appears to turn over very slowly in mouse lung with half-life best estimated in years.