For the direct quantitative determination of 3? Diol G by enzyme immunoassay in human serum. The principle of the following enzyme immunoassay test follows the typical competitive binding scenario. Competition occurs between an unlabelled antigen (present in standards, controls and patient samples) and an enzyme-labelled antigen (conjugate) for a limited number of antibody binding sites on the microplate. The washing and decanting procedures remove unbound materials. After the washing step, the enzyme substrate is added. The enzymatic reaction is terminated by addition of the stopping solution. The absorbance is measured on a microtiter plate reader. The intensity of the colour formed is inversely proportional to the concentration of 3? Diol G in the sample. A set of standards is used to plot a standard curve from which the amount of 3? Diol G in patient samples and controls can be directly read.
5?-Androstane-3?, 17?-diol glucuronide is a C19 steroid and is either abbreviated as 3? Diol G, 5? Diol G or simply, ? Diol G. It is produced mainly as a metabolite of testosterone and dihydrotestosterone (DHT). It is largely produced in target peripheral tissues such as the skin, especially around hair follicles. The stimulation by large amounts of 3? Diol G leads to excessive hair formation, notably where hair is not normally present in women.
In recent years the interest in the measurement of this steroid has increased among clinical investigators studying women suffering from idiopathic hirsutism.
Among the steroids known to be precursors for 3? Diol G are dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), dihydrotestosterone (DHT), androstenedione and testosterone. Only 3? Diol G has been shown to increase with hirsutism and decrease with treatment. This correlation has also been demonstrated in patients with polycystic ovarian syndrome (PCO). 3? Diol G determinations have therefore proved to be a useful indicator in a variety of ways including monitoring the progress of treatment of idiopathic hirsutism and women with PCO.
Furthermore, diabetic patients (both men and women) under cyclosporine A therapy have shown increased 3? Diol G levels, a side effect resulting in the appearance of hair in previously hairless areas.