Changes in the nervous system state and peripheral blood parameters under benzene intoxication during an experiment

Benzene is a widely spread chemical health risk factor. Our research goal was to examine the nervous system state and the blood system state under benzene intoxication during an experiment. An acute experiment was performed on 45 white mice with 5-fold poisoning with benzene; a chronic one was performed on 72 rabbits being under inhalation exposure to benzene during 4 months, its concentrations increasing and fluctuating. We determined the following blood parameters: number of reticulocytes, eosinophils, basocytes, and erythrocytes; erythrocytes sedimentation rate; blood clotting period; blood clot retraction; plasma re-calcification period; plasma tolerance to heparin; prothrombin time; prothrombin index; fibrinogen concentration; blood fibrinolytic activity; acetylcholine and choline esterase contents. We also determined adrenalin, noradrenalin, dopamine, and dihydroxyphenylalanine contents in urine. Acute experiments results revealed that one-time exposure to benzene exerted a narcotic effect on the central nervous system which had an excitation phase and inhibition phase. Under a repeat exposure to benzene animals' drug intoxication was shorter. And here neutrophils / leucocytes gradient first increased to 139.5 % from its standards value and then when down under consequent intoxications. We detected relevant changes in morphological picture of animals' peripheral blood and their central and vegetative nervous system under chronic exposure to intermittent and increasing benzene concentrations. So, our research revealed that effects exerted by benzene in small concentrations led to apparent shifts in white blood and catecholamines (adrenalin, noradrenalin, dopamine, and dihydroxyphenylalanine). We also detected certain signs that cate-cholamines endogenous reserves (dihydroxyphenylalanine ) were depleted and, and also signs of eosinophils-basocytes disso-ciation; such prognostic signs were considered to be unfavorable as it was exactly at that moment of time (the 4th month of poi-soning) when substantial changes (leucopenia, granulopenia, lymphopenia, and monocytopenia) occurred in blood. Fluctuating benzene concentrations exerted more apparent toxic effects in comparison with simply increasing toxicant concentrations