Conversion of p-tyrosine to p-tyramine in the isolated perfused rat kidney: modulation by perfusate concentrations of p-tyrosine.
We used the isolated perfused rat kidney to evaluate the role of renal decarboxylation of p-tyrosine as the source of urinary p-tyramine. Kidneys were perfused with concentrations of p-tyrosine ranging from 0.02 mM to 2.0 mM. p-Tyramine was measured by a sensitive and specific radioenzymatic assay. An increase in the perfusate concentration of p-tyrosine resulted in a significant increase in p-tyramine production that was blocked by the addition of NSD-1015, an inhibitor of aromatic-1-amino decarboxylase (AADC). We conclude p-tyrosine is the precursor for the renal production of p-tyramine, renal AADC catalyzes the formation of urinary p-tyramine, synthesized p-tyramine is predominantly excreted in the urine, and p-tyramine synthesis is modulated by the arterial delivery of p-tyrosine to the kidney.
Brier
M E
ME
Department of Medicine, University of Louisville, Kentucky 40292.
Bowsher
R R
RR
Mayer
P R
PR
Henry
D P
DP
D000818:Animals; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D014439:Tyramine / Q000378:metabolism* / Q000652:urine; D014443:Tyrosine / Q000378:metabolism*
D014443:Tyrosine; D014439:Tyramine