Salivary glands-an unisex organ?

Abstract

Usually no distinction is made between female and male salivary glands although cyclic changes of andor differences in serum and salivary sex steroid concentrations characterize women and men. Moreover, sexual dimorphism is well recognized in salivary glands of rodents. Salivary glands contain estrogen and androgen receptors and are, according to modern high throughput technologies, subjected to gender differences not explainable by gene dose effects by the X chromosome alone. Because sex steroids are lipophilic, it is often thought that approximately 10% of them passively diffuse from plasma to saliva. Indeed, saliva can find use as sample material in sports medicine, pediatrics, veterinary medicine and behavioral sciences. Last but not least, humans and other primates are unique in that they have a reticular zone in their adrenal cortex, which produces dehydroepiandrosterone and androstendione pro-hormones. These are processed in peripheral tissues, not only in female breast and uterus and male prostate, but also in salivary glands by an intracrine enzymatic machinery to active 17-estradiol, dihydrotestosterone and others, to satisfy and buffer against a constantly changing needs caused by circadian, menstrual, pregnancy and chronobiological hormonal changes in the systemic circulation. Female dominance of Sjögrens syndrome and certain forms of salivary gland cancer probably reflect these gender-based differences. © 2010 John Wiley & Sons AS.