Distribution of 2-ethylhexanoic acid in mice and rats after an intraperitoneal injection

The distribution of 2-ethylhexanoic acid (2-EHA), a new wood preservative agent was studied in mice and rats. 2-14C-EHA in rat blood, brain, liver and kidney was quantitated by liquid scintillation analysis and by wholebody autoradiography in mice. A single intraperitoneal dose of 2-14C-EHA was injected in both species. Animals were sacrificed 30 min., 2 and 6 hr after the administration of 2-14C-EHA in autoradiography experiments. The highest uptake of 2-14C-EHA was observed in the liver, kidney and blood of mice. In contrast, low uptake of 2-14C-EHA was seen in the brain. 2-14C-EHA was well detectable in the olfactory bulb and in the salivary gland. In rats, at 2 hr after administration the highest concentration of 2-14C-EHA occurred in blood (0.3% of the total dose/g tissue). The radioactivity in the liver (0.2%) and kidney (0.1%) was also relatively high. The concentration of 2-14C-EHA was low in the brain (0.02%). By 6 hr. the radioactivity had decreased rapidly and was hardly measurable at 24 hr after the administration. The results suggest that 2-EHA is rapidly cleared from the tissues.