
%0 Journal Article
%A Park, J. I. 
%A Jang, Y. 
%A Lee, E. S. 
%T 335 EFFECT OF VITAMIN E ON THE DEVELOPMENT OF BOVINE OOCYTES AFTER CHEMICAL ACTIVATION
%J Reproduction, Fertility and Development
%D 2006/12/12
%V 19
%N 1
%P 283-283
%K 
%R https://doi.org/10.1071/RDV19N1AB335
%U https://www.publish.csiro.au/paper/RDV19N1AB335 
%X Oxidative stress is known to induce apoptotic cell death by reactive oxygen species (ROS) generated from in vitro culture systems. This study was conducted to evaluate the effect of Vitamin E (VitE), as antioxidant, on development of bovine embryos activated in vitro. Bovine ovaries were collected from slaughtered cows at a local abattoir. Oocytes were aspirated from follicles 3-8 mm in diameter and transferred to maturation medium: tissue culture medium (TCM)-199 supplemented with 10% (v/v) fetal calf serum, 100 mg/mL-1 l-cysteine, 20 mg/mL-1 sodium pyruvate, gonadotropins (250 IU each of eCG and hCG/mL), 10 mg/mL-1 epidermal growth factor, and 100 µM VitE. Oocytes were cultured at 38.9°C in 5% CO2 in humidified air. After 22 hours of culture, oocytes with polar bodies were selected and subjected to activation treatments. Oocytes were exposed to calcium ionomycin (5 µM for 5 min), followed by incubation with 6-DMAP (2 mM) for 3.5 hours in medium supplemented with or without VitE (100 µM). After activation, oocytes were cultured in mSOF medium containing 0.8% BSA at 38.9°C in 5% CO2, 5% O2 in humidified air for 7&#8211;8 days. Cell numbers were counted by the number of nuclei of blastocysts stained with Hoechst 33342, and apoptosis was detected by TUNEL assay using a MK500 kit (Takara Bio, Inc., Otsu, Shiga, Japan). Total cell and apoptotic cell number were determined under a fluorescence microscope. Data were analyzed using Student&apos;s t-test and chi-square test. The cleavage and blastocyst rates were significantly higher (P < 0.05) after activation with VitE (78.1&percnt; and 16.3&percnt;, n &equals; 80) than without VitE (66.7&percnt; and 11.0&percnt;, n &equals; 60). Total cell numbers were also significantly higher (P < 0.05) in blastocysts after activation with VitE (143.0 &plusmn; 34.02, n &equals; 21) than in those without VitE (127.63 &plusmn; 40.25, n &equals; 20). However, the percentage of TUNEL-positive (apoptotic) cells was similar between blastocysts activated with VitE (5.38 &plusmn; 2.22) and those without VitE (6.76 &plusmn; 1.98). The results of the present study demonstrate that vitamin E added to activation medium promoted further development of activated embryos, although its role in the alleviation of apoptosis remains unclear. 
