Concentration-dependent depletion of non-protein sulfhydryl (NPSH) content in lung, heart and liver tissue of rats and mice after acute inhalation exposure to butadiene

Abstract

The effects of different exposure concentrations of butadiene on the cellular non-protein sulfhydryl (NPSH) content of liver, lung and heart tissue were investigated in B6C3F 1 mice and Sprague-Dawley rats. Groups of male animals of both species were exposed for 7 h to 10, 50, 100, 250, 500, 1000 and 2000 ppm butadiene. Immediately after exposure, NPSH content of liver, lung and heart tissue was determined according to a modified Ellman procedure. A comparison of both species shows that a dose-dependent NPSH depletion can be observed in mice for all tissues examined. In rats, liver NPSH content shows a major reduction at high exposure concentrations only. In mice, depletion of NPSH content of liver, lung and heart tissue starts at exposure concentrations of about 250 ppm butadiene. A reduction in NPSH content of about 80% is observed for lung tissue at 1000 ppm and for liver and heart tissue at exposure concentrations of 2000 ppm butadiene. The data on tissue concentrations of NPSH obtained after exposure of rats and mice to butadiene reflect the quantitative differences in butadiene metabolism and in biological effectivity of reactive butadiene intermediates between both species.