Abstract: Prostaglandins (PGs) are a group of lipid mediators, which were synthesized by the cyclooxygenase (COX) pathway from arachidonic acid. In mammals, it has been proved that PG plays a number of essential roles in reproductive processes, such as ovulation, fertilization, implantation, decidualization, uterus smooth muscle contraction, luteal regression and follicle development. In the hen, administration of PG induces oviposition and stimulates uterine contractility. At midsequence of ovipositions, the concentration of PG in the ovarian venous plasma was 5 to 20 times higher than in peripheral plasma.PG was released in a pulsate format in the avian, this not only stimulates uterine contractility, but also acted as the second messenger of gonadotropins for cAMP action in the granulosa cells’ proliferation. Hence,the change of PG content in follicle fluid played an important role in prehierarchical follicle selection.

Key words: prostaglandins; prehierarchical follicle; follicle development; avian