Induction of lysinuria in the rat by two para-substituted guanidinophenylalanines

1. p-Guanidino- and p-guanidinomethyl-phenylalanine increase the renal excretion of lysine especially and, to some extent, cystine in the phenylalanine-loaded rat. The methyl derivative is the more effective. 2. The lysinuria is dose-dependent, reversible, pronounced when the intravenous infusion of analogue exceeds 10 mumol min-1 kg-1 and does not appear to be secondary to changes in urine flow or sodium excretion. 3. A mechanism for induced basic amino-aciduria conditions is suggested.