Kafkas Üniversitesi Veteriner Fakültesi Dergisi 2018 , Vol 24 , Issue 2
Effects of Ovary Transport and Storage Temperature on In Vitro Maturation and Cumulus Cell Apoptosis Rates in Cat Oocytes
Mithat EVECEN1, Kamber DEMİR1, Ramazan ARICI1, Selin YAĞCIOĞLU1, Nur ERSOY1, Nilhan COŞKUN1, Elif ARMUTAK2, Ayça ÜVEZ2, Ebru GÜREL GÜREVİN3, Ahmet ESER1, Hatem ATALLA4, Kemal AK1, Serhat PABUCCUOĞLU1, Sema BİRLER1
1Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Istanbul University, TR-34320 Avcılar, Istanbul - TURKEY
2Department of Histology and Embryology, Faculty of Veterinary Medicine, Istanbul University, TR-34320 Avcılar, Istanbul - TURKEY
3Department of Biology, Faculty of Science, Istanbul University, TR-34134 Vezneciler, Istanbul - TURKEY
4Faculty of Veterinary Medicine, An Najah National University, Nablus - PALESTINE
DOI : 10.9775/kvfd.2017.18880 The objective of the present study was to examine the effects of two different transport temperature (37°C vs 4°C) and cold storage of ovaries for 24 h on cumulus cell apoptosis and maturation rates of cat oocytes in vitro. Ovaries were collected from 15 ovariohysterectomized domestic cats and maintained and transported to the laboratory in phosphate buffer saline at 37°C and 4°C. In order to determine the effects of storing time, some ovaries transported at 4°C were stored at the same temperature for 24 h. Selected cumulus oocyte complexes (COCs) were matured for 48 h at 38°C in four-well petri dishes containing 500 μL of modified oviduct medium (mSOF) under mineral oil in a 5% CO2 incubator with nearly 100% humidified. The morphological features of apoptosis were analysed in the cumulus cells at the beginning of in vitro maturation in both transporting temperature groups and after 24 h of cold stored group. The degree of apoptosis in cumulus cells were measured by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL). The IVM rates of oocytes were determined using Hoechst (33342) staining. Although the apoptotic morphological features were seen rarely and in similar rates in 37 and 4°C transporting groups (19.40 and 21.55%, P>0.001), it was seen more intensely in the 24 h cold stored group (34.80%, P<0.001). The IVM findings were similar (49.77, 44.55%) at 37°C and 4°C groups (P>0.05), and importantly lower at 4°C transporting and 24 h cold stored groups (18.90%, P<0.05). In conclusion, the results of this study suggest that (I) cumulus cells of cat oocytes are partially exposed to apoptosis during transportation at warm or cold temperature, (II) storing of ovaries for 24 h at 4°C causes apoptosis of the cumulus cells at much higher rates and (III) storing of ovaries for 24 h at 4°C affects negatively IVM rate of oocytes. Keywords : Cat, Ovary, Transport temperature, Oocyte, Cumulus, Apoptosis