Blood and organ distribution of mono (2-ethylhexyl) phthalate (MEHP) in rats exposed to di (2-ethylhexyl) phthalate (DEHP) via diet

Di(2-ethylhexyl) phthalate (DEHP) undergoes hydrolysis in the gastrointestinal tract when orally administered to rats, and is mainly distributed in the body as mono(2-ethylhexyl) phthalate (MEHP). MEHP is thought to be involved in testicular and hepatotoxicity. Therefore, clarifying the distribution of MEHP in blood and organs after oral administration of DEHP is important.

In this study, male Sprague-Dawley rats were fed 1% and 2% DEHP diets for two weeks and then examined the distribution of MEHP and DEHP concentrations in blood and organs. The following results were obtained.

·         MEHP concentrations in the 1% group were plasma: 16.7-40.8 μg/ml, testis: 0.9-3.2 μg/g, liver: 21.5-43.6 μg/g, kidney: 6.8-9.6 μg/g and MEHP concentrations in the 2 %group were plasma: 58.5-147.4 μg/ml, testis: 10.5-30.0 μg/g, liver: 44.2-97.1 μg/g, kidney: 18.6-56.7 μg/g.
·         Mean MEHP concentrations in blood and organs were dose-dependent, but with considerable inter-individual variability.
·         MEHP concentrations by organ were highest in liver, followed by kidney, and lowest in testis.
·         DEHP was detected in plasma, testis, liverIn this study, male Sprague-Dawley rats were fed 1% and 2% DEHP diets for two weeks and then examined the distribution of MEHP and DEHP concentrations in blood and organs. The following results were obtained.

, and kidney in both 1% and 2% groups in the range of 1-20 μg/g (μg/ml).
·         MEHP concentrations in testis, liver, and kidney were all strongly correlated with plasma MEHP concentrations.
A strong negative correlation was observed between MEHP concentration in testis and testicular weight, and between plasma MEHP concentrations and testicular weight. This suggests a close relationship between MEHP and testicular toxicity.