02182naa a2200229 a 450000100080000000500110000800800410001910000180006024501020007826000090018052015200018965000190170965300170172865300230174565300170176870000250178570000210181070000170183170000250184870000180187377300610189119807862024-02-05       2013    bl uuuu     u00u1 u    #d1 aPOLISSENI, J.  aImpact of the use of gonadotropins on embryonic development - a rat model.h[electronic resource]  c2013  aObjective: To evaluate the impact of in vivo superovulation on early embryonic development in a rat model. Methods: Experiment 1: Female Wistar rats were superovulated with injection of PMSG followed by hCG 48 hours later. Embryos were collected 24 h after hCG administration. Experiment 2: Female Wistar rats (n=16) were distrbuted to a control or superovulated group. Embryos were collected 48 and 72 h after hCG administration. The total number of embryonic structures and the embryo quality grades were analyzed by Chi-squared test. Between-group differences in ovarian weight were assessed by Student’s t-test. Results: Experiment 1: 931 embryos were collected from 66 animals, with a mean of 16.3±9.5 structures per animal. The superovulation was successful in 89.4% of the animals, and 98.2% of the embryos collected from superovulated animals were viable. Experiment 2: The superovulated group had heavier ovaries and produced more embryos than the control group (P &lt 0.001); however, these embryos contained fewer cells than controls at 72 hours after hCG administration (P&lt0.001). A greater percentage of embryos from the superovulated group were classified as grade I or grade II relative to embryos from the control group (P &lt 0.001 and P = 0.008, respectively). Conclusion: Superovulation was successful in the Wistar rat model and resulted in a greater number of embryos collected per animal. However, embryos produced as a result of superovulation developed more slowly than control embryos.  asuperovulation  aAnimal model  aEmbryo development  aEmbryo grade1 aGRÁZIB, J. G. V. de1 aGUERRA, M. DE O.1 aMILEN, L. C.1 aCAMARGO, L. S. de A.1 aPETERS, V. M.  tJBRA Assisted Reproductiongv. 17, n. 1, p. 32-36, 2013.