Mechanism of action of calcitonin on secretion in rat submandibular gland

Salivary and serum biomarkers of inflammation in a man with metastatic medullary thyroid carcinoma and hyperreactive gingiva: a fourteen year odyssey

A peripheral (gingival) fibroma, a gingival cyst and hyperplastic gingivitis occurred simultaneously in a man with metastatic medullary thyroid carcinoma (MCT). The gingival growths and hyperplasia appeared to be related to poor oral hygiene rather than to the MTC. Despite the patient's improved oral hygiene, the hyperplastic gingivitis and peripheral fibroma recurred, and a new peripheral fibroma and gingival cyst developed, which prompted reconsideration of a link with the MTC. MTC cells secrete calcitonin (CT), procalcitonin (ProCT) and growth factors; the patient's serum CT and ProCT were several fold higher than normal. The patient's salivary CT and ProCT also were elevated, but α-amylase and epidermal growth factor (EGF) were not, compared to three healthy controls. A possible link between the MTC and gingival hyper-reactivity due to CT and/or ProCT promoting inflammatory cytokines, and the utility of salivary ProCT as an indicator of periodontitis in this patient were explored further. Unstimulated whole saliva and serum were collected from the patient followed by a standard periodontal examination before periodontal treatment, and 3 weeks and 3 months after treatment. This cycle was repeated 7 months after the previous periodontal treatment. The saliva was assayed for ProCT and the serum was assayed for ProCT, high sensitivity C-reactive protein (CRP), interleukin-6 (IL-6) and proadrenomedullin (ProADM). The results were analyzed for correlations among the severity of periodontitis and the biomarkers/cytokines. Only the salivary ProCT was correlated with the severity of periodontitis, i.e. it was higher just before and lower at 3 weeks and 3 months after each periodontal treatment. The patient's salivary ProCT content also was much higher than reported elsewhere. The other biomarkers/cytokines were within normal ranges. Our findings indicate that salivary ProCT is independent of serum ProCT and therefore may be a useful marker for moderate to severe periodontitis in patients with MTC. The greatly elevated salivary and serum CT and ProCT, and a trend toward correlation between the serum CRP and ProCT suggest a pro-inflammatory link between the MTC and the hyperreactive gingiva in this patient. Further studies are warranted to determine whether hyperplastic gingivitis and gingival growths, such as cysts and fibromas, occur with unusual frequency in patients with MTC.

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.

cAMP and cGMP in human parotid saliva: relationships to taste and smell dysfunction, gender, and age

Among the chemical moieties present in human parotid saliva, some, such as gustin or carbonic anhydrase VI, have been useful to distinguish patients with taste and smell dysfunction from normal subjects. To continue these studies we compared levels of salivary cAMP and cGMP in patients with taste and smell dysfunction with those in normal subjects. We were also interested in exploring physiological characteristics of salivary cAMP and cGMP including changes with gender and age because previous studies had not clearly defined these issues. To perform these studies parotid saliva was collected from 61 normal volunteers and 253 patients with taste and smell dysfunction. cAMP and cGMP were measured by a spectrophotometric 96 plate ELISA technique; parotid salivary protein and flow rate were also measured. Both cAMP and cGMP were found in saliva of normal subjects and patients in the detection range of the assay used. In patients mean concentrations of both cAMP and cGMP were lower than in normal subjects; for cAMP levels were lower among both men and women patients. cAMP was 7 to 10 times higher than cGMP in both normal subjects and patients. Concentrations of cAMP were consistently higher in normal women than in normal men. cAMP levels were generally lower and cGMP levels were generally higher than in previously reported studies. There was a complex pattern of change for both cAMP and cGMP with age with concentrations increasing to about age 50, then decreasing, then increasing again at age >70 years.