Effect Of Visfatin On Ovarian Ovulation Function In Aged Female Rats

Objectives To explore the effects of exogenous visfatin on the ovarian’s function andegg’s quality of the aged female rats by detecting the expression of vascular endothelialgrowth factor (VEGF) and endocrine gland vascular endothelial growth factor (EG-VEGF), and to provide experimental basis for medication of patients with poor ovarianresponse in clinical induced ovulation process.Methods Two group of different aged (12~16weeks,32~36weeks) SPF female SDrats (60rats in each group) were divided into two groups randomly. Based on inducedovulation as control group, the group treated with exogenous visfatin was defined astreatment group. In the first step, rats were given15IU pregnant mare serum in estrus byintraperitoneal injection for induced ovulation. At the same time, the treatment group wasgiven100ng/ml recombinant rat visfatin. In the second step,48hours after the injection,the rats were injected with50IU human chorionic gonadotropin (HCG) in enterocoelia. Inthe third step, the female rats were mated with male ones immediately. In the fourth step,18hours after the mating, the female rats were sacrificed by cervical dislocation, and thentheir fertilized eggs in bilateral fallopian tubes were taken out under the sterile conditionsand cultured in the petri dish.The bilateral ovarian were removed, and the right one wasfixed with formaldehyde by detecting the immunohistochemistry (IHC), microvesseldensity (MVD).The left ovary was placed into Trizol to detect mRNA expression ofVEGF and EG-VEGF by Realtime–PCR, and the remaining part was used to detect theprotein expression of VEGF and EG-VEGF by Western Blotting. The experiment datawere statistically analyzed by SPSS17.0software, and then expressed as the mean±standard deviation (x s). The intergroup differences were analyzed by single factorvariance, and the data between the two group were compared using SNK test, withP<0.05statistically significant.Results Firstly, the mean number of zygotes, number of fertilized eggs, cleavage rateand embryo quantity in young control group, young treatment group and elder treatmentgroup were higher than those of elder control group, and the differences were statisticallysignificant (P <0.05), while the differences among young control group, young treatmentgroup and aged treatment group were of no statistical significance (P>0.05). Secondly, the expression level of MVD, VEGF and EG-VEGF of ovary in young control group,young treatment group and aged treatment group were higher than those of the controlgroup, and the differences were statistically significant (P <0.05), while there was nostatistical significance among young control group, young treatment group and agedtreatment group (P>0.05).Conclusions1Age was a major factor to cause reproductive capacity decline, andexogenous visfatin can significantly improve ovary faction.2The improvement of agedfemale rats’ reproductive capacity by exogenous visfatin may be the result of enhancedgeneration of ovarian blood vessels.