ABSTRACT - The aim of the present study was to analyze the effects of in vitro exposure to Di-(2-ethylhexyl) phthalate (DEHP), an industrial plasticizer, on cumulus-oocyte maturation and energy/oxidative status in the horse. After in vitro maturation (IVM) in presence of 0.12, 12 and 1200 μM DEHP, cumulus cells (CCs) were removed and evaluated for apoptosis and intracellular reactive oxygen species (ROS) levels. Oocytes were evaluated for nuclear chromatin configuration. Matured (Metaphase-II stage; MII) oocytes were further evaluated for cytoplasmic energy/oxidative parameters. DEHP significantly inhibited oocyte maturation when added at low doses (0.12 μM; P<0.05). This effect was related to increased CC apoptosis (P<0.001) and reduced ROS levels (P<0.0001). At higher doses (12 and 1200 μM), DEHP induced apoptosis (P<0.0001) and ROS increase (P<0.0001) in CCs without affecting oocyte maturation. In DEHP-exposed MII oocytes, mitochondrial (mt) distribution patterns, apparent energy status, intracellular ROS localization and levels, mt/ROS colocalization and total SOD activity did not vary, whereas increased ATP content (P<0.05), possibly of glycolytic origin, was found. Co-treatment with the antioxidant N-Acetyl-Cysteine reversed apoptosis and efficiently scavenged excessive ROS in DEHP-treated CCs without improving oocyte maturation. In conclusion, in vitro exposure to DEHP inhibits equine oocyte maturation without altering ooplasmic energy/oxidative parameters in matured oocytes.
Effects of DEHP exposure on energy/oxidative parameters of the cumulus-oocyte complexes in the mare
SARDANELLI, Anna Maria;MARTINO N. A.;DELL'AQUILA, Maria Elena
2012-01-01
Abstract
ABSTRACT - The aim of the present study was to analyze the effects of in vitro exposure to Di-(2-ethylhexyl) phthalate (DEHP), an industrial plasticizer, on cumulus-oocyte maturation and energy/oxidative status in the horse. After in vitro maturation (IVM) in presence of 0.12, 12 and 1200 μM DEHP, cumulus cells (CCs) were removed and evaluated for apoptosis and intracellular reactive oxygen species (ROS) levels. Oocytes were evaluated for nuclear chromatin configuration. Matured (Metaphase-II stage; MII) oocytes were further evaluated for cytoplasmic energy/oxidative parameters. DEHP significantly inhibited oocyte maturation when added at low doses (0.12 μM; P<0.05). This effect was related to increased CC apoptosis (P<0.001) and reduced ROS levels (P<0.0001). At higher doses (12 and 1200 μM), DEHP induced apoptosis (P<0.0001) and ROS increase (P<0.0001) in CCs without affecting oocyte maturation. In DEHP-exposed MII oocytes, mitochondrial (mt) distribution patterns, apparent energy status, intracellular ROS localization and levels, mt/ROS colocalization and total SOD activity did not vary, whereas increased ATP content (P<0.05), possibly of glycolytic origin, was found. Co-treatment with the antioxidant N-Acetyl-Cysteine reversed apoptosis and efficiently scavenged excessive ROS in DEHP-treated CCs without improving oocyte maturation. In conclusion, in vitro exposure to DEHP inhibits equine oocyte maturation without altering ooplasmic energy/oxidative parameters in matured oocytes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
