Abstract:
This study was performed to investigate the intrafollicular concentrations of oestradiol, progesterone, anti-Müllerian hormone (AMH), insulin-like growth factor-1 (IGF-1), inhibin-A, inhibin-B, and vascular endothelial growth factor (VEGF) during breeding season in mares. A total of 25 healthy, non-lactating mares with regular oestrous cycles were used. Follicular aspirations were performed from a preovulatory follicle (POF) and a subordinate follicle (SOF) during oestrus. The aspiration procedure was repeated one week later to collect follicular fluid sample during the luteal phase (luteal phase follicle, LPF). Follicular fluid IGF-1, inhibin-A and VEGF concentrations were not statistically different between follicle groups. LPF concentrations of oestradiol was the lowest and significantly different (P<0.001) from POF and SOF. The highest progesterone concentrations were measured in POF. SOF concentrations of progesterone were the lowest and significantly different from other follicle types (P<0.001). POF AMH concentrations were lower and significantly different (P<0.001) from other follicle groups. LPF inhibin-B concentrations were significantly higher (P<0.001) than POF and SOF levels. The data suggest that the levels of IGF-1, inhibin-A, and VEGF tend to be higher in preovulatory follicles despite the absence of significancy, however inhibin-B, oestradiol, progesterone and AMH show a variable pattern on the follicular basis throughout the oestrous cycley |
