Effect of di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate on in vitro developmental competence of bovine oocytes

摘要

In the last decade, potential exposure of humans and animals to industrial chemicals and pesticides has been a growing concern. In the present study, di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) were used to model the effects of endocrine-disrupting compounds and their risk in relation to early embryonic losses. Exposure of cumulus oocyte complexes during maturation to 50 micro M MEHP reduced the proportion of oocytes that underwent nuclear maturation (p<0.05) and increased the proportion of apoptotic oocytes (p<0.05). Furthermore, phthalates reduced cleavage rate in the MEHP-treated group (p<0.05) and the proportion of embryos developing to the blastocyst stage in both DEHP- and MEHP-treated groups (p<0.05). The total cell count for blastocysts developing from MEHP-treated oocytes was lower than in controls (p<0.05). Exposure of oocytes to MEHP during maturation reduced (p<0.05) the expression of ASAH1 (an anti-apoptotic factor), CCNA2 (involved in cell cycle control), and POU5F1 (responsible for pluripotency) in matured oocytes. Furthermore, the reduced mRNA expression of POU5F1 and ASAH1 lasted into two-cell stage embryos (p<0.05). Phthalate-induced alterations in POU5F1, ASAH1, and CCNA2 expression might explain in part the reduced developmental competence of MEHP-treated oocytes.Digital Object Identifier http://dx.doi.org/10.1007/s10565-012-9230-1