The physiological role of hormones in saliva

The assessment of hormones in saliva has gained wide acceptance in clinical endocrinology. To date, there is no hypothesis as to why some hormones can be found in saliva, while others cannot, and whether there is a physiological consequence of this fact. A number of carefully performed studies give examples of important physiological hormonal activity in saliva. Steroids, such as androgens, act as pheromones in olfactory communication of various mammalian species, such as facilitating mating behavior in swine or serving as odor cues for rodent nestlings. Salivary peptide hormones, such as epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), and amines such as melatonin, are involved in the regulation of inflammatory processes and in the promotion of cell proliferation, and contribute to a rapid wound healing in the oropharyngeal epithelia. Current data provide evidence of the involvement of salivary cytokines, such as interleukin-8 and leptin, in tumorgenesis in the oral cavity and the salivary glands. The tumor tissues express and release significantly more of these cytokines than healthy glands. Consequently, the assessment of salivary hormone profiles may provide promising targets for diagnostic tumor markers.