[Molecular heterogeneity of collagen in normal and pathologic states]

Collagen, the main protein of the connective tissue, is characterized by considerable heterogeneity. More than five types of collagen molecules, or seven types of subunits coded by different structural genes are studied. Both in the age aspects and under different pathologies the ratio of collagen types in some tissues changes, new types of collagen molecules are synthetized. Collagen not peculiar to the rat skin in normal state is synthetized in the unbalanced nitrogen nutrition with addition of amino acids, such as glycin and tryptophan.