A chemiluminescent method for the measurement of pregnanetriol-3α-glucuronide in human diluted urine

✍ Scribed by Pinzani, P. ;Magini, A. ;Franceschetti, F. ;Messeri, G. ;Pazzagli, M.

• Publisher: John Wiley and Sons
• Year: 1989
• Weight: 361 KB
• Volume: 4
• Category: Article
• ISSN: 0884-3996
• DOI: 10.1002/bio.1170040176

✦ Synopsis

Pregnanetriol-3a-glucuronide (PTG) is the majority urinary metabolite of 17hydroxyprogesterone (170HP) and it typically increases in the commonest form of congenital adrenal hyperplasia (CAH), due t o 21 hydroxylase deficiency.

We developed a simple chemiluminescent immunoassay for the direct measurement of PTG in diluted urine in order t o avoid the preliminary hydrolysis and extraction steps that are usually employed in gas-liquid chromatographic methods. The immunogenic complex PTG-bovine-serum-albumin was used t o induce the formation of specific antibodies in New Zealand rabbits. In addition, PTG was conjugated t o aminoethylethylisoluminol and the resulting tracer was characterized by mass spectrometry and used t o monitor the immunological reaction. The characteristics of the antibody were determined with regard t o specificity and sensitivity. The precision of the assay method was also established.

PTG excretion was studied before and after the ACTH stimulation test (1 mg synthetic ACTH i.m.1 in 11 normal women and in one subject affected by CAH due t o 21-hydroxylase deficiency. PTG levels well correlated with 170HP plasma concentrations both under basal and stimulated conditions, in normal women as well as in the patient affected by CAH.