Parotid saliva cortisol in normal subjects: increase during pregnancy.

Cortisol concentration was measured by radioimmunoassay in parotid saliva: values for normal subjects averaged 15 nM at 8:00 and 4 nM at 18:00. Parotid saliva cortisol was shown to react promptly and in a clearcut fashion to factors leading to rise and fall in cortisol secretion. Cortisol levels in parotid saliva were uninfluenced in young women taken estrogen-containing drugs for contraceptive purposes; on the other hand, they increased significantly during the third trimester of pregnancy. This increase corresponds to the reported increase in ultrafilterable cortisol, itself being presumably the result of the hypersection of progesterone characterizing this physiological condition since progesterone competes with cortisol not only at the level of transcortin but also at that of cytoplasmic glucocorticoid receptors.