Veterinary Research Forum

Abstract Although equine chorionic gonadotropin (eCG) combined with gonadotropin-releasing hormone (GnRH) is known to improve reproductive rates by increasing the numbers of ovulating oocytes, the actions of these hormones on embryo implantation have not been elucidated. We herein eliminated the effects of embryos by performing embryo transfer and elucidated the effects on embryo implantation after hormonal treatment. The recipient mice were allocated to four groups, including control, eCG, GnRH, and eCG + GnRH groups. Well-developed blastocysts were transferred into recipients, and implantation sites were counted five days after embryo transfer. Our results revealed that embryo implantation rates in the eCG and eCG + GnRH groups were significantly lower than GnRH and control groups; eCG and eCG + GnRH groups didn’t differ, and the implantation rate was the lowest in the eCG + GnRH group. When we evaluated estrogen and progesterone concentrations in four groups on embryonic day 0.5 to embryonic day 3.5, we noted that serum estrogen levels in eCG + GnRH group were significantly higher than the other groups, while progesterone levels were significantly lower than the control group, and that the progesterone/estrogen ratio was significantly reduced relative to the control group. Finally, the expression of the endometrial receptivity-related Lif gene was significantly diminished in the eCG + GnRH and eCG groups compared to the other groups. These results suggest that eCG combined with GnRH as a super-ovulatory regimen reduced mouse embryo implantation rates via an estrogen-mediated impairment of endometrial receptivity.

Abstract Some pharmacological agents can be effective for peripheral nerve injuries treatments. Present study aimed to apply different agents and compare the nerve regenerative effects following crushed sciatic nerve injuries. Twenty four (n=24) adult male mice were conducted in this study. Standard unilateral left side sciatic nerve crush was performed with 2 mm width mosquito hemostat forceps. The mice were randomly divided into 4 groups with the same numbers in each group which received subcutaneously, estrogen (group I), tacrolimus (group II), the combination of estrogen and tacrolimus (group III), and saline 0.9%. Functional recovery, histopathology, and Immunohistochemistry (IHC), were assessed on days 14th and 28th. Walking track analysis on day 14th showed no significant difference between experimental groups (P>0.05) but they showed significant difference compared to the control group (P<0.05). At the same time, experimental groups showed similar results of inflammatory cell infiltration, axonal edema, and count with significant differences between the control (P<0.05). At the end of the study, group I and III showed a significant difference in functional recovery between group II and control (P<0.05). After fourth week significant histopathological difference of axonal count was observed in group III (P<0.05). On day 28th, only IHC assessment in group III increased more Glial fibrillary acidic protein (GFAP) expression compared with the same group on day 14th. This study revealed subcutaneous administration of combined estrogen and tacrolimus can be effective with acceptable results in nerve regeneration.