Prostaglandins in ovulation

Evidence accumulated using prostaglandin synthesis inhibitors, prostaglandin measurements, or prostaglandin antibodies in several species has supported the concept that a gonadotropin-induced preovulatory rise in follicular prostaglandins is required for ovulation. There are at least three questions which need to be answered for a further understanding of this requirement : 1) What is the mechanism by which gonadotropin can stimulate prostaglandin synthesis ? 2) In which cell type(s) are prostaglandins produced, and upon which do they act ? 3) What are the actions of prostaglandins which participate in ovulation ? There have been recent advances which partially answer the first two questions. Gonadotropins appear to stimulate prostaglandin synthesis by increasing the quantities of follicular cyclic AMP (or possibly cyclic GMP). Derivatives of both nucleotides have been found to be effective exogenously. The effect of gonadotropin on prostaglandin synthesis also exhibits a delay of several hours and requires macromolecular synthesis. As to the first portion of question two, it appears that granulosa cells produce the bulk of follicular prostaglandins. It is not clear at this time, however, which cell(s) respond to the