en 27563427 <p>Background: This study was aimed to assess the effects of angiotensin II (Ang II) supplementation to the In Vitro Maturation (IVM) and In Vitro Culture (IVC) media of vitrified-warmed ovine oocytes on their developmental competence and expression of Na⁺/K⁺/ATPase in resulting embryos.<br /> Methods: The slaughterhouse-derived immature oocytes (n=1069) were randomly distributed into four experimental groups: groups I and II) IVM/IVF and IVC of fresh and vitrified oocytes without angiotensin supplementation (Control-Fresh and Control-Vit groups, respectively); group III) IVM of vitrified oocytes in the presence of Ang II followed by IVF/IVC (Vit-IVM group); and group IV) IVM/IVF of vitrified oocytes followed by IVC wherein the embryos were exposed to Ang II on day 4 of IVC (Vit-D4 group). The embryos were immunostained with primary antibodies against Na⁺/K⁺/ATPase &alpha;₁ and &beta;₁ subunits.<br /> Results: In Vit-IVM and Vit-D4 groups, the rates of expanded and total blastocysts on day 7 as well as the proportion of blastocysts on day 8 were increased. The expression of Na⁺/K⁺/ATPase &alpha;1 and &beta;₁ subunits were positively influenced by the addition of Ang II on day 4 (Vit-D4 group).<br /> Conclusion: The addition of Ang II to the IVM and IVC media could improve blastocysts formation in vitrified sheep oocytes. This improvement might be related to the greater expression of Na⁺/K⁺/ATPase &alpha;₁ and &beta;₁ subunits when Ang II was added during IVC.</p> Angiotensin II, Na+/K+/ATPase, Oocyte, Ovine , Vitrification 139 144 https://www.ajmb.org/En/Article.aspx?id=247 https://www.ajmb.org/PDF/En/FullText/247.pdf Mohammad MehdiNaderiReproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran334SaraBorjian BoroujeniReproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran337AliSarvariReproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran335BanafshehHeidariReproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran503Mohammad MehdiAkhondiReproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran13Amir-HassanZarnaniReproductive Immunology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran7AbolfazlShiraziResearch Institute of Animal Embryo Technology, Shahrekord University, Shahrekord, Iran82