Microscopic observations, as well as the selective increase of the release of A rather than the release of E2 in response to pregnenolone infusion, confirmed that the MDS capillary membranes were placed in the theca layer, where the predominant secretory product is A. This is further supported by the fact that the basal concentration of A in the perfusate was more than 2-fold higher than that of E2. LH and the peptides infused into the capillary membrane are considered to diffuse along a concentration gradient into the extracellular fluid and modify the cellular secretory function in a paracrine manner. Based on the observation from the preliminary experiment that substances infused in one line did not affect the hormonal release in other lines separated by at least a 5-mm distance, a maximum of four lines per follicle were implanted. The individual response of each line to the infused peptides suggests that the microenvironment of each line was independent from that of other lines. birth control pills
LH stimulated the release of steroids (P4, A, and E2) and PGE2 from the theca layer. The results are comparable to those of previous studies on isolated preovulatory follicles from rabbits, on the capacity for prostaglandin synthesis in preovulatory follicles from sheep, and on bovine the-ca cell cultures, in which LH increased the release of E2, A, P4, and PGE2 in vitro.