Effect of Isotretinoin on Nuclear Maturation and Fertilization Rate of Bovine Oocyte
Author(s): Abdolreza Ranjbar, Mohammad Amin Eslampour, Mehran Farhoodi Moghadam
The blastulation rate following in vitro maturation, fertilization and culture of bovine oocytes is generally low. Numerous studies have reported that oxidative stress (OS) has detrimental effects on quality of gametes and embryos under culture conditions. Thus, adding some substances to IVM and IVF media could protect oocytes and early embryos against oxidative stress.
The purpose of this study was to evaluate whether enriching the oocyte in in vitro maturation medium with isotretinoin (13-cis-retinoic acid) would improve the in vitro embryo production efficiency in cattle. To this end, 250 oocytes were collected and divided into five groups of 50 oocytes: Group 1: Washing medium (WM) and maturation medium (MM) without retinoic acid; group 2: The WM supplemented with 5 nm isotretinoin and the MM without retinoic acid; group 3: The WM without retinoic acid and the MM plus 5 nm isotretinoin; group 4: The WM supplemented with 5 nm isotretinoin and the MM plus 5 nm isotretinoin; and group 5: The WM without retinoic acid and the MM plus 10 nm isotretinoin.
The results showed that nuclear maturation in the groups 3 and 4 had higher percentage than that in the groups 1, 2 and 5. The percentage of oocytes reaching the metaphase II stage significantly increased (P<0.05) in the 5 nm RA-treated groups compared to groups without retinoic acid (58.30%) and 10 nm RA (50%). RA supplementation significantly improved the fertilization rate (76%) compared with groups without retinoic acid (56%). The results demonstrated that addition of 5 nm isotretinoin to the in vitro oocyte maturation medium enhanced the maturation and fertilization rates of bovine oocyte.