Small intestinal absorption of glycine and glycyl-glycine in patients with chronic renal failure.
Intestinal absorption of glycine and glycyl-glycine was studied in 9 patients with chronic renal insufficiency (mean creatinine clearance 9 ml/min) and 7 healthy controls. After an oral load of the amino acid or dipeptide, plasma alpha-amino nitrogen (alpha-NH2N) was measured repeatedly for two hours and the area under curve (AUC) was calculated using the trapezoidal rule. In uremic patients, plasma alpha-NH2N was significantly lower after glycine than after glycyl-glycine at 30, 45 and 60 min and also AUC was smaller after the amino acid indicating a reduced total uptake. One patient with severe, terminal uremia had a flat curve after glycine administration. In control subjects, plasma levels were lower after glycine than after glycyl-glycine at 30 min but AUC did not differ between the amino acid and the dipeptide. Generally these results agree with those in earlier studies of non-uremic man showing that, in small intestine, dipeptides are taken up better and by a different mechanism than amino acids.
D000328:Adult; D000368:Aged; D000588:Amines / Q000097:blood; D000596:Amino Acids / Q000097:blood; D004151:Dipeptides / Q000097:blood*; D005260:Female; D005998:Glycine / Q000097:blood*; D006033:Glycylglycine / Q000097:blood*; D006801:Humans; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000097:blood*; D008297:Male; D008875:Middle Aged
D000588:Amines; D000596:Amino Acids; D004151:Dipeptides; D006033:Glycylglycine; D005998:Glycine