Dehydroepiandrosterone sulfate (DHEA-S) is a steroid hormone produced mainly in the adrenal cortex. DHEA-S is the sulfate form of the steroid DHEA and, like DHEA, is secreted in response to ACTH. Several studies have reported that DHEA-S secretion has a daily (circadian) rhythm, but other studies have not found such a pattern. Circulating DHEA-S has a longer half-life, slower clearance, and binds more strongly to albumin than DHEA. DHEA-S appears to serve largely as a precursor molecule that can circulate in various target tissues in the whole body. At these sites, sulfur (S) is removed to form DHEA (dehydroepiandrosterone) which is then further metabolized to various molecules which have estrogenic and androgenic actions. This process allows the supply of androgens and estrogens to the appropriate tissues without leaking significant amounts into the circulation. DHEA-S is also synthesized directly in the central nervous system, where it is believed to help protect nerve tissue from various harmful factors. DHEA-S has been studied for its relationship to psychological and physical stress and in various psychological and behavioral disorders.
The precursor molecule for the synthesis of DHEA is cholesterol. DHEA is produced by the adrenal glands, brain, ovaries, and testes and is a precursor molecule to the major sex steroids (estrogen, progesterone, and testosterone). It is sometimes called "anti-aging hormone" or "source of youth" and taking DHEA supplementation so that its levels are at youthful levels seems to create a feeling of well-being.
DHEA-S is a charged molecule and cannot diffuse through the neutral lipid membranes of salivary cells like other neutral steroids. The exact way of entering the saliva is not completely known. Previously, it was thought that DHEA-S could enter saliva only after compression through the gap junctions that exist between cells, and because it is a relatively large molecule, there are only small amounts in the saliva. Recent studies have identified a large family of organic anion transport polypeptides (OATPs) that actively transport molecules such as DHEA-S across membranes. There may be a similar way for DHEA-S to enter the salivary glands.
DHEA-S levels in saliva are quite low. Less than 0.1% of plasma DHEA-S levels are found in parodit saliva. However, because blood DHEA-S levels are 250 to 500 times higher than DHEA levels in women and men, respectively, the concentration of DHEA-S in the saliva is high enough to be measurable. Due to the restrictive way DHEA-S enters saliva, its saliva levels decrease as the saliva flow rate increases. Due to the much higher levels of DHEA-S in the blood, it is important to minimize the risk of blood contamination of saliva samples. DHEA-S levels in saliva and plasma show a significant positive correlation.
Measurements of hormones in saliva are an excellent choice, because the collection of the sample is non-invasive and easy, without the possible complications and inconvenience of blood sampling, while ensuring the sensitivity and accuracy of the measurements.
