[The levels of electrolytes and nitric oxide in saliva of students under mental-emotional exertion].

The influence of examination-induced psycho-emotional stress on students' hemodynamic parameters, nitric oxide (NO) level and electrolyte composition of saliva was investigated. Before examinations, the examinees with a sympathotonic response (75.0%) showed the increase of heart rate levels and blood pressure indices, the decline of salivary NO excretion that was retained within 24-hours after an exam. There was a significant negative correlation between the amount of NO and the values of blood pressure. The examinees with a parasympathetic response (25%) showed the elevated salivary NO level and lowered blood pressure indices in the pre- and post- examinational periods. Throughout the examination period the increased autonomic tone of the organism contributes to the changes of the electrolyte composition of saliva. In pre-examination period the examinees with sympathotonic response demonstrated a significant decrease of the concentration of Na+ in saliva, that persisted after exams also. Hyponatremia was associated with the increased K+ and decreased Na+/K+ ratio. Before exams the level of Na+ in the saliva of the students of the II group increased, at the same time concentration of K+ decreased. After the exam there was a reduction of Na+, which, however, did not reach the initial level.