Plasma proteins glycoprotein catabolism

Most of the plasma proteins are glycoproteins and, except for the ) globulins that are synthesized in lymphoid tissue and the widely distributed cells of the reticuloendothelial system, they are synthesized in the liver. They exist in equilibrium with the tissue proteins and are subject to continuous catabolism and replacement. Nevertheless, homologous plasma proteins (i.e. plasma proteins derived from the same species) appear able to pass into the tissue cells without prior degradation. No particular organ has been shown to be the sole site of catabolism of any one plasma protein. 

Making some allowance for the different identities of the plasma proteins listed in Table VI and those mentioned above, there are considerable discrepancies in the circulation time of those labeled in the protein and in the amino sugar residues. The possibility that carbohydrate residues might be removed from glycoproteins before general catabolism of the protein part... 

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