ABSTRACT
Follicular fluid (FF) is an avascular compartment within the mammalian ovary separated from the perifollicular stroma by the follicular wall that constitutes a blood-follicle barrier. FF plays a major role in the autocrine and paracrine regulation and also in the physiological, biochemical and metabolic aspects of the nuclear and cytoplasmic maturation of the oocyte and the process of ovulation. This fluid is also composed of locally produced substances within the follicle, which are related to the metabolic activity of follicular cells, and it is also in part an exudate of serum. The ovarian FF provides suitable microenvironment for the development, growth and maturation of the oocyte and is vital for the maintenance of fertility in the female. FF protects the oocyte from factors that induce premature resumption of meiosis, guards the oocyte from proteolytic attack, facilitates its extrusion during ovulation, and enhances sperm attraction, motility, and the acrosome reaction.