@article{article_532444, title={Influence of extenders and cooling rates on epididymal sperm of Lewis rat strain}, journal={Ankara Üniversitesi Veteriner Fakültesi Dergisi}, volume={62}, pages={57–62}, year={2015}, DOI={10.1501/Vetfak_0000002658}, author={Varışlı, Ömer and Agca, Cansu and Agca, Yüksel}, keywords={Cooling rate, epididymal sperm, extenders, freezing, Lewis rat strain}, abstract={The objective of this study was to determine the appropriate cooling rates and extender for improving the freezability of epididymal sperm of Lewis rat strain. The epididymal sperm from Lewis rats were suspended in different freezing extenders which were HEPES buffered Tyrode’s lactate (TL-HEPES), modified Kreb’s Ringer bicarbonate (mKRB), 3% dehydrated skim milk (SM), Salamon’s Tris-citrate (TRIS), and TES/Tris (TES). The extenders contained 20% (v/v) egg yolk (EY), 0.75% equex paste (EP) and 0.1 M raffinose or 0.1 M sucrose. The sperm samples were frozen by automated freezer, using various cooling rates (10, 40, 70, and 100 °C/min). After thawing, sperm samples were examined for integrity of plasma and acrosomal integrity, and mitochondrial membrane potential (MMP). Type of extenders had significant effect on cryosurvival (p<0.05). The post-thaw highest motility (27.5%) was achieved for the sperm samples frozen in the presence of TES extender (p<0.05). As a result, although cooling rate did not significantly affect cryopreservation, the extenders affected post-thaw sperm parameters and TES considerably improved the freezability of epididymal Lewis rat sperm}, number={1}, publisher={Ankara University}