Collagen synthesis inhibition by PGE2 within the human follicular wall--one possible mechanism underlying ovulation

Follicular wall specimens were taken from various parts of human preovulatory follicles as well as from less developed follicles. The tunica albuginea was isolated and incubated for 2 h in Krebs Ringer bicarbonate buffer containing 3H-proline in the presence or absence of PGE2 (0.1 microgram/ml). Following incubation the incorporated radioactivity was determined and related to the protein content of each strip. PGE2 had a specific effect on the incorporation of 3H-proline into protein in the follicular wall. In the apical part of the preovulatory follicle a significantly decreased incorporation was registered, indicating a reduced net synthesis of collagen. However, PGE2 was without effect on specimens derived from the non-apical parts of the preovulatory follicles as well as from the less developed follicles. It is suggested that the registered biochemical changes induced by PGE2 are of importance for the process of human ovulation.