aminohippuric acid

Para-aminohippurate (PAH), also known as aminohippuric acid, is a small molecule diagnostic agent historically used to measure effective renal plasma flow (ERPF) and evaluate renal tubular secretory capacity. Administered intravenously, PAH is freely filtered by the glomeruli and actively secreted by the proximal renal tubules via organic anion transporters (primarily OAT1 and OAT3), with approximately 90% cleared in a single circulation. More recently, PAH has been investigated as a nephroprotective co-infusion during peptide receptor radionuclide therapy (PRRT) for neuroendocrine tumors. By saturating the organic anion transporters in the proximal tubules, PAH competitively inhibits the renal reabsorption and accumulation of radiolabeled small peptides (such as Lu-177-DOTATOC), offering a faster and better-tolerated alternative to standard amino acid infusions.

Brand names

Nephrotest

Other names

4-aminohippuric acidaminohippurateaminohippurate sodiump-aminohippuratep-aminohippuric acidPAHPAHApara-aminohippuratepara-aminohippuric acidparaaminohippurateparaaminohippuric acidsodium p-aminohippuratesodium para-aminohippurate