Of p-aminohippuric acid

H. Shimada, B. Moewes, and G. Burckhardt. Indirect coupling to Na+ of p-aminohippuric acid uptake into rat renal basolateral membrane vesicles. Am J Physiol 253 F795-F801 (1987). 

Wedeen RP, Weiner B. The distribution of p-aminohippuric acid in rat kidney slices. I. Tubular localization. Kidney Int 1973 3 205-213. 

Kikuchi R, Kusuhara H, Sugiyama D, et al. Contribution of organic anion transporter 3 (Slc22a8) to the elimination of p-aminohippuric acid and benzylpenicillin across the blood-brain barrier. J Pharmacol Exp Ther 2003 306 51-58. 

The carrier-mediated uptake of p-aminohippuric acid (PAH) into BBMV (Figure 7) and PAH accumulation by renal cortical slices [69,77] were also significantly reduced by CPH treatment (1200 mg/kg/d for 3d). Furthermore, the transport of other cephalosporins across the renal brush border membrane is also affected by CPH-treatment the uptake of cephalexin and cefotiam into BBMV was greatly reduced whereas the uptake of CPH remained unaffected [77]. Secretion of cephalosporins across the brush border membrane is assumed to occur by the PAH-system as well as by the organic cation/H+-antiporter [127,133]. Reabsorption of many cephalosporins is performed by the dipeptide transport system [69, 133]. The unaffected uptake of CPH into BBMV from CPH-treated rats indicates that CPH is transported by a system different from the... 

Fig. 8-96. Separation of p-aminohippuric acid in urine. - Separator column IonPac AS4A eluent 0.0017 mol/L NaHC03 + 0.0018 mol/L Na2C03 flow rate 2 mL/min detection UV (254 nm) injection 50 gL sample (diluted 1 100).

McGilvery and Cohen later extended their studies to the formation of ornithuric acids from a- and 6-benzoyl-L-ornithine and p-aminobenzoic acid. They succeeded in obtaining enzymatic activity in an acetone powder of the sedimentable macroparticles of chicken liver homogenate, and found the conditions for the synthesis of the ornithuric acids, and the indications of the mechanisms involved, the same as in the synthesis of p-aminohippuric acid. 

Measurement of the renal plasma flow by measuring the clearance of low levels of p-aminohippuric acid. 

At the time ATP was implicated in the synthesis of hippuric acid, a more searching study had been undertaken independently by Cohen and McGilvery (38-40) of an analogous reaction, the synthesis of p-aminohippuric (PAH) acid from p-aminobenzoic acid (PAB) and glycine. PAB is a constituent of naturally occurring peptides (5,95). The discovery of the role of Co A in the synthesis of hippuric acid was made in Cohen s laboratory and was, indeed, led up to by the findings there on the synthesis of p-aminohippuric acid. 

Certain molecules, such as p-aminohippuric acid (Fig. 3.18), a metabolite of p-aminobenzoic acid are actively transported from the bloodstream into the tubules by a specific anion transport system. Organic anions and cations appear to be transported by separate transport systems located on the proximal convoluted tubule. Active transport is an energy-requiring process and therefore may be inhibited by metabolic inhibitors, and there may be competitive inhibition between endogenous and foreign compounds. For example, the competitive inhibition of the active excretion of uric acid by compounds such as probenecid may precipitate gout. 

The compound damages the pars recta portion of the proximal tubule with the loss of the brush border. The result is renal failure detected as glycosuria, proteinuria, loss of concentrating ability, and reduction in the clearance of inulin, p-aminohippuric acid, and tetraethylammonium ion. 

J. Libeer, S. Scharpe, et al., Simultaneous determination of p-aminobenzoic acid and p-aminohippuric acid in serum and urine by capillary gas chromatography with use of a nitrogen-phosphorus detector, Clin. Chim. Acta, 775 119-123 (1981). 

Disposition in the Body. Readily absorbed after oral administration. It is conjugated with aminoacetic acid to form p-aminohippuric acid which is excreted in the urine together with a small amount of / -aminobenzoyl glucuronide, / -acetamido-benzoyl glucuronide, and traces of / -acetamidohippuric acid, p-acetamidobenzoic acid, and unchanged aminobenzoic acid. Aminobenzoic acid may be detected in the urine as a metabolite of amethocaine, benzocaine, and procaine. 

Clinical analysis of certain biological markers in urine, including ascorbic acid (1), is very important. An automatic method for solid-phase extraction coupled to CE with DA-UVD was developed and optimized, including autosampling and post-run operations to restore the instrument to readiness for the next sample. The whole cycle lasted 13.01 min, thus allowing the simultaneous determination in urine of creatine (34), creatinine (35), uric acid (3), p-aminohippuric acid (36) and l" . ... 

An assay for uric acid in urine employing a PDMS and/or glass microchip for capillary electrophoresis has also been developed. This device can achieve separation and quantitation of uric acid in less than 30 seconds and a linear response over a range of 0 to lOOpM/L. To facilitate this measurement, dilutions of urine of the order of fiftyfold to seventy-fivefold were required. Other similar devices for the renal markers creatine, creatinine, p-aminohippuric acid, and uric acid in urine,and a microchip-based method for zone electrophoretic analysis of oxalate m urine have been reported. 

Gloff CA, Benet LZ. Differential effects of the degree of renal damage on p-aminohippuric acid and inulin clearances in rats. J Pharmacokinet Biopharm 1989 17 169-177. 

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