Salivary Androstenedione

Intended Use

The Salimetrics Androstenedione Enzyme Immunoassay Kit is a competitive immunoassay specifically designed and validated for the quantitative measurement of salivary Androstenedione. It is not intended for diagnostic use. It is intended only for research use in humans and some animals. Salimetrics has not validated this kit for serum or plasma samples.

Introduction

Androstenedione (4-androstene-3,17-dione) is produced in the adrenal gland and gonads. Androstenedione has weak intrinsic androgenic activity (estimated at less than 20% of testosterone), but it is a prohormone for potent androgens (testosterone) and estrogens. The biochemical evidence supporting the effect of Androstenedione on elevation of circulating levels of testosterone and estrogens is strong, and site-of-action direct conversion of Androstenedione to testosterone is well known. Secretion of Androstenedione in women exceeds that of testosterone as significant extra-adrenal conversion of Androstenedione to testosterone occurs in females. High levels of Androstenedione may confer androgenic risk, especially in females, and estrogenic risks, especially in males. Children and adolescents are particularly vulnerable to the effects of Androstenedione conversion to active sex steroids. These effects may disrupt normal sexual development, specifically virilization in girls associated with severe acne, excessive body hair, disruption of the menstrual cycle, and infertility. The conversion of Androstenedione to estrogens can cause feminization of boys. In both boys and girls, the combined effects of excessive androgens and estrogens can induce premature puberty and significantly compromise adult stature by causing early closure of growth plates of long bones. Measurement of serum Androstenedione is used as a marker of androgen biosynthesis. High circulating Androstenedione levels are indicated in virilizing congential adrenal hyperplasia, polycystic ovarian syndrome, and other causes of hirsutism in women. Elevated Androstenedione levels may also occur as a result of adrenal or ovarian tumors. The high serum-saliva correlation for Androstenedione suggests that individual differences in serum Androstenedione levels may be accurately estimated using saliva as a non-invasive alternative specime. The U.S. FDA has released high profile warnings to the public about serious health effects related to Androstenedione administration. Androstenedione is an additive in many products generally advertised as dietary supplements that enhance athletic performance. Use of these supplements has the potential to cause extreme values in this assay. Also, it is noteworthy that the effects of oral Androstenedione administration on circulating levels of testosterone and estrogen do not account for all of the actions of these products. Target tissues of anabolic steroids contain abundant enzymes that convert circulating Androstenedione to testosterone right at the site of action without necessarily affecting circulating testosterone levels. To ensure the most accurate results, this salivary immunoassay is designed using a matrix that matches saliva. The level of Androstenedione in saliva (pg/mL) is significantly lower than levels in the general circulation (ng/mL). The standard curve range of this assay is sensitive enough to capture individual differences in the Androstenedione levels expected in saliva. The current protocol uses only 50 µL of saliva per test. No separation or extractions are necessary.

Androstenedione Assay Principle

This is a competitive immunoassay kit. Androstenedione in standards and samples compete with Androstenedione conjugated to horseradish peroxidase for the antibody binding sites on a microtitre plate. After incubation, unbound components are washed away. Bound Androstenedione Enzyme Conjugate is measured by the reaction of the horseradish peroxidase enzyme to the substrate tetramethylbenzidine (TMB). This reaction produces a blue color. A yellow color is formed after stopping the reaction with an acidic solution. The optical density is read on a standard plate reader at 450 nm. The amount of Androstenedione Enzyme Conjugate detected is inversely proportional to the amount of Androstenedione present in the sample.