Hormones in saliva: mode of entry and consequent implications for clinical interpretation.

Abstract

Assay of hormones in saliva would be more convenient than assay in blood, but there is no information on the route by which hormones enter saliva, information that would provide insight into the clinical value of such assays. We have examined the mode of entry of various hormones into saliva. The results suggest that unconjugated steroids enter saliva by diffusing through the cells of the salivary glands and that their concentration in saliva does not depend on the rate of saliva production. Conjugated steroids enter saliva via "ultrafiltration" through the tight junctions between the acinar cells, and their concentration in saliva is highly flow-rate dependent. Thyroxin and choriogonadotropin enter saliva via the ultrafiltration route or by contamination of the saliva by plasma or gingival fluid. We conclude that the salivary concentration of unconjugated steroids may usefully reflect the concentration of free (nonprotein-bound) steroids in plasma. Conversely, the concentration of conjugated steroids, thyroxin, and protein hormones such as choriogonadotropin in saliva probably does not reflect their concentration in plasma in any clinically useful way.

Excavation of caries lesions induces transient decrease of total salivary immunoglobulin A concentration

“…On the one hand, mechanical manipulations, water rinsing and water sucking may destroy the saliva film in the oral cavity. While cortisol rapidly diffuses from the blood (25), secretion of IgA from storage in the mucosa requires more time, so that the total salivary IgA returned to the initial level only after 30 minutes following the excavation.…”

The diagnostic uses of saliva

“…Since the pioneering studies of SHAN-NON et al (60) it has generally been recognized that the lipid-soluble unconjugated steroids pass readily into saliva and that their concentrations in saliva are proportional to the concentrations of free, unbound steroids in plasma (2). The conjugated steroids diffuse with great difficulty because of their low lipid-solubility and high molecular weight (62). An exception has recently been noted for corticosteroid binding globulin (CBG) and some modification of the assay may be required (63).…”

Measurement of salivary cortisol with liquid chromatography‐tandem mass spectrometry in patients undergoing dynamic endocrine testing

“…SalC levels do not depend on saliva flow rate and samples are stable at room temperature for weeks. 5 Most importantly, cortisol in saliva correlates well with the unbound fraction of SerC and is unaffected by changes in serum corticosteroid-binding globulin (CBG) levels. 5 However, a major limitation of the determination of cortisol levels, especially at the very low levels found in saliva, is the crossreactivity by exogenous glucocorticoids and endogenous cortisol precursors and metabolites in immunoassays.…”

“…5 Most importantly, cortisol in saliva correlates well with the unbound fraction of SerC and is unaffected by changes in serum corticosteroid-binding globulin (CBG) levels. 5 However, a major limitation of the determination of cortisol levels, especially at the very low levels found in saliva, is the crossreactivity by exogenous glucocorticoids and endogenous cortisol precursors and metabolites in immunoassays. Although a good correlation exists between results generated by different assays, absolute values show significant discrepancies and assay-specific reference ranges are needed.…”