Different effects of oral glycine and methionine on urinary lithogenic substances.
Nine male healthy volunteers were examined during a control period, during an oral glycine load (45 g/day, 600 mmol) and oral methionine (6 g/day, 40 mmol). Glycine caused a significant increase of urinary oxalate above baseline (from 644 to 797 mumol/day) without change in calciuria (4.74 vs 4.84 mmol/day). In contrast methionine caused no change of oxaluria, but a significant increase in calciuria (from 4.74 to 6.9 mmol/day). Alterations of lithogenic ions in urine after protein ingestion are mediated by different amino acids. The particular lithogenic risk of animal protein may be related to its high methionine/cystine and glycine content.
D000328:Adult; D002118:Calcium / Q000652:urine; D004044:Dietary Proteins / Q000009:adverse effects; D005998:Glycine / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008715:Methionine / Q000494:pharmacology*; D010070:Oxalates / Q000652:urine; D019815:Oxalic Acid; D014545:Urinary Calculi / Q000209:etiology* / Q000652:urine
D004044:Dietary Proteins; D010070:Oxalates; D019815:Oxalic Acid; D008715:Methionine; D002118:Calcium; D005998:Glycine