Change in the content of a series of components of rat lung connective tissue in the process of aging

: Content of soluble and insoluble collagen, glycosamine glycans, glycoproteins, lipids and nucleic acids was studied in rat lungs during postnatal ontogenesis (up to 32 months). Three age groups of animals, corresponding to juvenile, mature and old age, were used. Intensive collagenoformation and high content of soluble collagen fraction were found in animals of juvenile age. Mature age was characterized by static equilibrium between soluble and insoluble collagen fractions as well as by stabilization in concentration of RNA, hexuronic acids, hexoses, tyrosine, sialic acids and total lipids. Decrease of DNA concentration with simultaneous increase in phospholipid content preceded in ageing the alteration in collagen composition - elevation in insoluble and loss of soluble its fractions. At the ageing period content of glycosamines was relatively decreased but concentration of other substances varied slightly.