Alternative high-performance liquid chromatographic assay for p-aminohippuric acid (PAH): effect of aging on PAH excretion in the isolated perfused rat kidney

摘要: Para-aminohippuric acid (PAH), an indicator of renal plasma flow, is a commonly used marker organic anion transport by the kidney. An analytical method for PAH using HPLC was developed. The simple, fast and requires minimum amount solvent. Sample preparation involved protein precipitation with zinc sulfate. Para-amino benzoic utilized as internal standard (IS). Chromatography performed reversed-phase phenyl column UV detection at wavelength 254 nm. Mobile phase consisted 0.1 M acetic acetonitrile (99:1) flow rate 1 ml/min. assay validated over concentration range from to 25 microg/ml. Accuracy, precision, reproducibility specificity established coefficients variation 0.99). study effect aging on excretion in isolated perfused rat kidney model. Experiments were conducted kidneys young (2-3 months, n=6), adult (6-9 n=5) aged (12-16 n=3) male Sprague-Dawley rats initial drug 20 Significant differences function (e.g. glomerular filtration glucose reabsorption) observed kidneys. Despite 5-fold reduction rate, clearance (kidney weight-corrected) decreased only 2-fold (2.2+/-0.42 ml/min per gram) compared (4.6+/-0.70 gram, P<0.05) rats. Furthermore, ratio significantly higher (27+/-8.0 vs. 15+/-5.0, P<0.05). These preliminary findings challenge 'Whole Nephron Hypothesis' that assumes parallel reductions secretory capacity secondary disease or aging.