  The purpose of the present study is to evaluate changes in chromatin of human
buccal epithelium under the influence of stressing factor - dosed physical
activity. Investigations were performed in a group of students (13 men) of age
19-23. Cells were stained on a slide by a 2% orcein solution in 45% acetic acid
during 1 h. The following physiological indexes were determined: arterial blood
pressure, pulse frequency, and frequency of breathing. The physical stress
produced by the dosed physical activity causes the considerable increase of
degree of heterochromatinization in the cell nuclei of human buccal epithelium.
As a rule, the level of heterochromatinization increases after first stage of
training, but in some donors it increases significantly only after the second
stage of training.
