Untitled

Abstract

Retinoids are recognized as important regulators of vertebrate development, cell differentiation, and tissue function. Previous studies, performed both in vivo and in vitro, indicate that retinoids influence several reproductive events, including follicular development, oocyte maturation and early embryonic development. The present study evaluated in vitro effects of retinol addition to media containing maturing bovine oocytes and developing embryos in both a low oxygen atmosphere (7%) and under atmospheric oxygen conditions (20%). In the first experiment, abbatoir collected bovine oocytes were matured in the presence or absence of varying concentrations of retinol. After a 22-24 hour maturation period the oocytes were fertilized, denuded 18 hours later and cultured in a modified synthetic oviductal fluid (mSOF) in a humidified atmosphere at 38.5 degrees C, 5% CO2, 7% O2 and 88% N2. Cleavage rates did not differ among control and retinoltreated oocytes in all three experiments. Addition of 5 micromolar retinol to the maturation medium (IVM) tended (p < 0.07) to increase blastocyst formation (blastocyst/putative zygote; 26.1% +/-2.2%) compared to the controls (21.9% +/-1.9%). Further analysis revealed when blastocyst development rates fell below 20% in the control groups, 5 micromolar retinol treatment dramatically improved embryonic development, measured by blastocyst/putative zygote rate (14.4 +/-2.1 vs 23.7 +/-2.5; p < 0.02). The 5 micomolar retinol treatment also enhanced the blastocyst/ cleaved rate by nearly 10% (23.7% vs 34.6%; p < 0.02). In the second and third experiments addition of 5 micromolar retinol to the embryo culture medium (IVC) under low oxygen conditions did not significantly improve cleavage or blastocyst rates, but 5 micromolar retinol significantly increased blastocyst development under 20% O2 conditions (p < 0.001). These studies demonstrate that supplementation of 5 micromolar retinol to the maturation medium may improve embryonic development of bovine oocytes indicated by their increased blastocyst rate. A significant improvement in the blastocyst development with the 5 micromolar retinol treatment under atmospheric conditions suggests a beneficial antioxidant effect during embryo culture.

In vitro maturation of porcine oocytes with retinoids improves embryonic development

“…Moreover, the number of cells per blastocyst was not influenced by any of the ROH treatments. These results are in disagreement with those obtained in bovine IVF, where it has been reported that 5000 nm ROH during IVM increases embryonic development to the blastocyst stage (Livingston et al 2004). It may be that different concentrations of ROH to those used in the present study are required during porcine IVM to achieve improved embryo development.…”

“…This detrimental effect could be related to a retinoid imbalance that has been shown to be highly correlated with developmental abnormalities (Morriss-Kay and Ward 1999). In support of this hypothesis, high concentrations of retinoids during IVM, such as 500 nm RA and 100 µm ROH (Livingston et al 2004), have been shown to be detrimental for bovine oocytes. In contrast with these findings, Lima et al (2006) reported that the addition of 500 nm RA to bovine IVM medium enhanced blastocyst formation.…”

“…Gomez et al 2003;Huang et al 2006). The different concentrations of retinoids used between studies could also have been responsible for these discrepancies, given that the effects of these compounds are dependent on their concentration Livingston et al 2004;Lima et al 2006).…”

“…Ikeda, unpubl. data) and embryonic development and quality (Duque et al 2002;Gomez et al 2003;Hidalgo et al 2003;Livingston et al 2004;Lima et al 2006). Despite the beneficial effects of retinol, a suitable dose for the different retinol metabolites has yet to be determined, because both excessive and inadequate exposure to retinol and its metabolites can be detrimental for mouse and bovine embryo development (Sporn and Roberts 1991;Huang et al 2006).…”

Sığır İn Vitro Embriyo Üretiminde Sistamin ve 13-Cis-Retinoik Asitin Etkisi

“…Duque et al [8] showed that the cytoplasmic competence of bovine oocytes improved in the presence of cis-retinoic acid during prematuration. Moreover, Livingston et al [13] demonstrated that the addition of retinol to the IVM medium may improve the embryonic development and blastocyst rate of bovine oocytes.…”