17-alpha hydroxy Progesterone ELISA kit description:

Diagnostic Automation 17-Hydroxyprogesterone (17-OH progesterone or 17OHP) is a C-21 steroid hormone produced in the adrenal gland and gonads, during the synthesis of glucocorticoids and sex steroids. It is derived from progesterone via 17-hydroxylase, a P450c17 enzyme, or from 17-hydroxypregnenolone via 3ß-hydroxysteroid dehydrogenase/?5-4 isomerase. 17a -OHP has no defined physiologic role except as a precursor molecule. Serum 17a -OHP levels are age-dependent, with peak levels observed during fetal life and the immediate postnatal period. During the first week of life, serum 17a -OHP levels fall ~50-fold as compared to cord blood values.



A small transient increase occurs in male infants 30-60 days postnatally. Levels for both sexes remain at constant low levels during childhood, and then progressively increase during puberty reaching adult levels of ~100 ng/dL (~3.03 nmol/L). As with cortisol, serum 17a ?OHP levels normally have an ACTH-dependent diurnal variation, with peak levels in the morning and a nadir at night. In addition, ovarian production of 17a -OHP increases during the luteal phase of the menstrual cycle. 17-hydroxyprogesterone is a natural progestin and in pregnancy increases in the third trimester primarily due to fetal adrenal production. Normal levels are 3-90 ng/dl in children and in women, 15-70 ng/dl prior to ovulation, and 35-290 ng/dl during the luteal phase. Measurements of levels of 17-hydroxyprogesterone are useful in the evaluation of patients with suspected congenital adrenal hyperplasia as the typical enzymes that are defective, namely 21-hydroxylase and 11ß-hydroxilase, lead to a build-up of 17OHP. In contrast, the rare patient with 17a-hydroxylase deficiency will have very low or undetectable levels of 17OHP. Elevated serum 17 a -OHP levels at baseline and/or after ACTH stimulation have also been reported in other forms of adrenal hyperplasia.

17a OH Progesterone (antigen) in the sample competes with horseradish peroxidase 17a OH Progesterone (enzyme-labeled antigen) for binding onto the limited number of anti- 17a OH Progesterone coated on the microplates (solid phase). After incubation, the bound/free separation is performed by a simple solid-phase washing. The enzyme substrate (H2O2) and the TMB-substrate (TMB) are added. After an appropriate time has elapsed for maximum colour development, the enzyme reaction is stopped and the absorbance is determined. 17a OH Progesterone concentration in the sample is calculated based on a series by a set of standard. The colour intensity is inversely proportional to the 17a OH Progesterone concentration in the sample.