PABA Abstracts 2

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Exocrine pancreatic function as determined in a same-day test with use of bentiromide and p-aminosalicylic acid

         (Berg, Chesner et al. 1986) Download

We describe a new approach to the bentiromide test of exocrine pancreatic function, p-Aminosalicylic acid (PAS), a compound closely related to the bentiromide fragment p-aminobenzoic acid (PABA), is used as a marker of the pharmacokinetic behavior of PABA to derive a PABA excretion index. This index is identical to that derived with [14C]-PABA. Concentrations of both PABA and PAS are measured in urine by "high-performance" liquid chromatography, which avoids the drug interferences encountered with established assays of PABA. We discuss the practical and diagnostic advantages of this new approach to the bentiromide test.

Studies on the metabolic effects of para-aminobenzoate. II. Effect on kidney cortex gluconeogenesis in the rat and mouse

         (Duboff and Zarafonetis 1973) Download

Update of exocrine functional diagnostics in chronic pancreatitis

         (Nojgaard, Olesen et al. 2013) Download

Diagnostics of pancreatic insufficiency rely mainly on tests of pancreatic exocrine function based on either measurement of pancreatic secretion or the secondary effects resulting from lack of digestive enzymes or imaging modalities. These methods have been developing rapidly over the last decades, and the aims of this review were to describe exocrine functional testing and imaging of the pancreas in chronic pancreatitis..

Assessment of pancreatic exocrine function

         (Puntis 1993) Download


A prospective, comparative study of the para-aminobenzoic acid test and faecal elastase 1 in the assessment of exocrine pancreatic function

         (Sonwalkar, Holbrook et al. 2003) Download

BACKGROUND: The assessment of exocrine pancreatic insufficiency is part of the routine work-up of patients with persistent diarrhoea or suspected steatorrhoea. Direct and indirect tests for the diagnosis of exocrine pancreatic insufficiency have their drawbacks. Measurement of faecal elastase 1 by enzyme-linked immunoabsorbent assay is a simple, non-invasive, robust test for exocrine pancreatic insufficiency. METHODS: We performed a prospective comparison of the para-aminobenzoic acid test and faecal elastase 1 test in 45 patients being investigated for diarrhoea or suspected steatorrhoea. Details of clinical suspicion, imaging and response to treatment were recorded. RESULTS: Exocrine pancreatic function was normal in 20 patients with normal para-aminobenzoic acid and faecal elastase 1 levels. Eight patients had exocrine pancreatic insufficiency with low para-aminobenzoic acid and faecal elastase 1 levels, which improved with enzyme supplementation. In 14 of the 15 patients with low or borderline low para-aminobenzoic acid and normal faecal elastase 1 levels, a non-pancreatic cause was found; one patient had a false positive para-aminobenzoic acid test. Two had normal para-aminobenzoic acid but low faecal elastase 1 levels. One improved with pancreatic supplementation, and imaging revealed chronic pancreatitis. The other had a false positive faecal elastase 1 test related to profuse diarrhoea. CONCLUSIONS: Faecal elastase 1 estimation is a simple, non-invasive, robust test of exocrine pancreatic insufficiency, performed on an out-patient stool sample. Its diagnostic performance is superior to that of the para-aminobenzoic acid test in investigating patients with diarrhoea or suspected steatorrhoea.

Para-aminobenzoate inhibition of precipitation of urine salts

         (Zarafonetis, Batsakis et al. 1979) Download

Lehmann's observation that potassium para-aminobenzoate has a "salt precipitating preventive effect" in urine was confirmed in rats. This effect persisted during the 3-week period of drug administration. There was associated no significant change in urine volume, osmolality, or per cent solids. Since there is a large clinical experience in the chronic use of even larger doses, it would appear quite feasible to determine the clinical usefulness of this property of para-aminobenzoate in the prevention of recurrent renal calculi.


References

Berg, J. D., I. M. Chesner, et al. (1986). "Exocrine pancreatic function as determined in a same-day test with use of bentiromide and p-aminosalicylic acid." Clin Chem 32(6): 1010-2. [PMID: 3486726]

Duboff, G. S. and C. J. Zarafonetis (1973). "Studies on the metabolic effects of para-aminobenzoate. II. Effect on kidney cortex gluconeogenesis in the rat and mouse." Res Commun Chem Pathol Pharmacol 6(1): 247-51. [PMID: 4734000]

Nojgaard, C., S. S. Olesen, et al. (2013). "Update of exocrine functional diagnostics in chronic pancreatitis." Clin Physiol Funct Imaging 33(3): 167-72. [PMID: 23522009]

Puntis, J. W. (1993). "Assessment of pancreatic exocrine function." Arch Dis Child 69(1): 99-101. [PMID: 8024314]

Sonwalkar, S. A., I. B. Holbrook, et al. (2003). "A prospective, comparative study of the para-aminobenzoic acid test and faecal elastase 1 in the assessment of exocrine pancreatic function." Aliment Pharmacol Ther 17(3): 467-71. [PMID: 12562462]

Zarafonetis, C. J., J. G. Batsakis, et al. (1979). "Para-aminobenzoate inhibition of precipitation of urine salts." Res Commun Chem Pathol Pharmacol 23(2): 403-6. [PMID: 313589]