Concentrations of thiocyanate and hypothiocyanite in the saliva of young adults.

The study was conducted to determine thiocyanate (SCN-) and hypothiocyanite (OSCN-) concentrations in resting (RWS) and stimulated whole saliva (SWS) and stimulated parotid saliva (SPS) of 20 healthy young adults aged 21-29 y. Samples of saliva were collected at 12:30, immediately before lunch. Resting saliva was collected by expectoration, and stimulated saliva was collected during the uniform chewing of paraffin wax. Parotid secretion was collected using a modified Carlsson-Crittenden cup (Carlsson et al., Am, J. Physiol., 26, 169-177, 1910). SCN- concentration was determined by the ferric nitrate method (Betts et al., J. Am. Chem. Soc., 75, 5721-5727, 1953) whilst OSCN- was assayed using 2-mercaptoethanol as a reducing agent (Pruitt et al., Caries Res., 16, 315-323, 1982). In RWS, SWS and SPS, the mean SCN- concentrations (in mM) were 1.48 +/- 0.59(S.D.), 0.90 +/- 0.56(S.D.) and 1.24 +/- 0.65(S.D.) whilst the mean OSCN- concentrations (in microM) were 31.21 +/- 13.54(S.D.), 24.90 +/- 12.61 and 30.19 +/- 23.35(S.D.) in the respective salivas. The presence of OSCN- in the secretion collected from the parotid gland supported previous findings by Tenovuo and Pruitt (Tenovuo et al., J. Oral Path, ol. 13, 573-584, 1984), who suggested an endogenous glandular (eukaryotic) source of hydrogen peroxide (H2O2), since parotid saliva from healthy glands is devoid of bacteria and leukocytes.