CYTOKINES IN SALIVA - BASAL CONCENTRATIONS AND THE EFFECT OF HIGH AMBIENT HEAT (SAUNA)

The aim of this study is to investigate the presence of several interl eukins in saliva and how their concentrations may be modified after ph ysical stress. The effects of one kind of somatic stress (sauna heat) on the concentrations of salivary cytokines were studied using ELISA a ssay. In addition, saliva cortisol was assayed. Fourteen volunteers pa rticipated in this study. Each subject attended one control and one st ress session which took place at the same hour on different days. Sali va was collected on the control day immediately after a 15-min rest pe riod in a seated position (R1), and again after an additional 30-min s eated period (R2). On the test day, saliva was collected after 15 min of sitting (S1) and 30 min later (S2) following exposure to the heat o f a sauna (90 degrees C, 10 min, 40 per cent humidity). We found that saliva contains the multifunctional polypeptide cytokines interleukin- 1 beta, tumour necrosis factor alpha and the receptor for interleukin- 2 with the basal mean concentrations (geometric mean; SD in parenthesi s) of 172 (106; 148) ng/l, 46 (20; 67) ng/l and 9 (6; 7) pM, respectiv ely. Interleukin-6 was detectable in only 60 per cent of the specimens investigated. Interleukin-2 and the receptor for interleukin-6 were n ot detectable. We examined the statistical differences between the rat io R2/R1 (the changes which occurred during the resting period) and S2 /S1 (the changes during the exposure to heat). We observed a significa ntly higher S2/S1 ratio for the tumour necrosis factor alpha in males, compared to the control ratio (2.5+/-2.4 versus 0.7+/-0.7, N=6, p<0.0 5 using the Wilcoxon signed rank test). Our results indicate that a si tuation which induced an elevated body temperature was associated with a rise in the concentration of the salivary tumour necrosis factor al pha.