Zunaira saleh2 days ago

Para aminohippuric acid

Measurement of renal plasma flow from the renal clearance of para-aminohippuric acid (PAH). PAH is freely filtered by the glomerular capillaries and is also secreted from the peritubular capillary blood into the tubular lumen. The amount of PAH in the plasma of the renal artery is about equal to the amount of PAH excreted in the urine. Therefore, the renal plasma flow can be calculated from the clearance of PAH. To be more accurate, one can correct for the percentage of PAH that is still in the blood when it leaves the kidneys. PPAH, arterial plasma PAH concentration; UPAH, urine PAH concentration; V, urine flow rate.