title: Psychological stress as a determinant of protein levels and salivary-induced aggregation of Streptococcus gordonii in human whole saliva.
abstract: Several pathologies of the oral cavity have been associated with stress, so we investigated salivary-induced aggregation during psychological stress. In addition, salivary total protein, alpha-amylase, and secretory immunoglobulin A (s-IgA) were assessed. In this longitudinal study, 28 dental students provided unstimulated whole saliva during 10 minutes before an academic examination and subsequently 2 weeks and 6 weeks later in a nonstress situation. The effect of whole saliva on the aggregation of Streptococcus gordonii (HG 222) was determined spectrophotometrically. The results shows a significant stress-mediated increase of salivary total protein concentration, alpha-amylase activity, amylase/protein ratio, alpha-amylase output, s-IgA concentration, and s-IgA output. There was also a trend for increased total protein output, whereas salivary flow rate was unchanged. The aggregation of S. gordonii in whole saliva collected before examination was 13.1%, whereas the aggregation in whole saliva collected during nonstress was 23.3%. This reduction was statistically significant (p < .01). Furthermore, the decrease in bacterial aggregation was related to the increase in state-anxiety (p < .05). The reduction in aggregation of S. gordonii under stress was not correlated with changes in salivary flow rate, s-IgA concentration, total protein concentration, or alpha-amylase activity. These results suggest that acute psychological stress exerts its influence on both salivary composition and salivary function. Reduced bacterial aggregation may be a contributing factor in the often reported relationship between stress and impaired oral health.
authors.affiliation: Department of General Pathology, Academic Centre for Dentistry, ACTA, Amsterdam, The Netherlands.
authors.forename: J A
authors.initials: JA
authors.lastname: Bosch
authors.forename: H S
authors.initials: HS
authors.lastname: Brand
authors.forename: T J
authors.initials: TJ
authors.lastname: Ligtenberg
authors.forename: B
authors.initials: B
authors.lastname: Bermond
authors.forename: J
authors.initials: J
authors.lastname: Hoogstraten
authors.forename: A V
authors.initials: AV
authors.lastname: Nieuw Amerongen
mesh_terms: D000328:Adult; D000681:Amylases / Q000378:metabolism; D001143:Arousal / Q000502:physiology; D005260:Female; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D007071:Immunoglobulin A, Secretory / Q000378:metabolism*; D008297:Male; D012016:Reference Values; D012307:Risk Factors; D012463:Saliva / Q000276:immunology*; D012471:Salivary Proteins and Peptides / Q000378:metabolism*; D013291:Streptococcus / Q000276:immunology*; D013315:Stress, Psychological / Q000150:complications* / Q000276:immunology
chemical_list: D007071:Immunoglobulin A, Secretory; D012471:Salivary Proteins and Peptides; D000681:Amylases