The influence of sarin on various physiological functions in rats following single or repeated low-level inhalation exposure.

Long-term effects of low doses of highly toxic organophosphorus agent sarin on various hematological and biochemical markers and physiological functions were studied in rats exposed to sarin by inhalation. The results indicate that low-level sarin-exposed rats show long-term increase in studied markers of stress and decrease in synthesis of DNA de novo without the disturbance of the functions of cholinergic nervous system. Moreover, sarin at low doses is able to induce some neurotoxic effects including an increase in the excitability of central nervous system in rats at 3 mo following inhalation exposure. Relatively long-term spatial discrimination impairments in rats exposed to low-level sarin was demonstrated too. Therefore, nerve agents such as sarin seem to be harmful not only at high, clinically symptomatic doses but also at low doses without acute clinical manifestation of overstimulation of cholinergic nervous system because of long-term manifestation of alteration of neurophysiological and neurobehavioral functions in sarin-exposed rats.