Plasma Proteins and the Gastrointestinal Tract

LEAKAGE of plasma proteins into the gastrointestinal tract is a major cause of hypoproteinemia in many diseases1 2 3 4 5 6 and, indeed, may play an important part in the normal degradation of plasma proteins.7 8 9 10 Early clinical studies described a syndrome of hypoproteinemia inexplicable by decreased synthesis or external loss of plasma protein.11 12 13 14 Studies of I131 turnover in patients with this syndrome showed an increase in albumin catabolism, but did not indicate the mechanism and site of this protein degradation.11 , 12 , 14 , 15 Hydrolysis of plasma proteins entering the gastrointestinal lumen, with reabsorption of their amino acids, delayed the recognition of this site of plasma protein loss, . . .