Journal of Advanced Biomedical Sciences

Background & Objectives: Neuropeptides are involved in various functions such as regulation of reproductive system function. With regards to the prevalence of reproductive disorders all over the world, this study is aimed at determining the effect of spexin on function of pituitary-gonadal axis in mature female rats.
Material & Methods: In this experimental study, 40 mature female rats were used and divided into control, sham and three experimental groups receiving spexin at doses 5, 25 and 50μg/kg. All injections were administered intraperitoneally during 5 days. Finally, after phlebotomizing the animals for measuring FSH, LH, estradiol, progesterone and testosterone, their ovaries were removed and after tissue sectioning, the follicles were counted by using physical dissector technique. The obtained data were analyzed using ANOVA and Duncan tests through SPSS 18 software, considering the significance level of data at the level of P>0.05.
Results: The results showed that spexin causes significant increase in FSH, number of multi-layer follicles, antral and corpora lutea. As well, the results showed that spexin caused a significant decrease in progesterone, the number of atretic follicles and graphs (P<0.01). This research showed that at doses 25 and 50μg/kg, spexin caused a significant decrease in LH, at dose 25μg/kg caused a significant increase in testosterone (P<0.05) and at dose 50μg/kg caused a significant increase in the number of single-layer follicles (P<0.01) compared to the control group. 
Conclusion: Spexin increases the number of multi-layer follicles and ovarian antral, by increasing the FSH serum level, nonetheless it causes the reduction of progesterone serum level, by decreasing the LH serum density.