Luteolysis and Thrombus Formation in Ovaries of Immature Superstimulated Golden Hamsters

Abstract

Thrombus appearance during luteolysis with and without exogenous prostaglandin (PGF2a) was studied in immature golden hamsters between days 4 and 7 after stimulation with pregnant mares' serum gonadotrophin (PMSG) followed by human chorionic gonadotrophin. Both ovaries were weighed and cut in series for light-microscopic evaluation. The fibrinolytic activity was determined by the fibrin slide .method after treatment with PGF2a on day 4 after PMSG stimulation and compared with controls of days 3 and 4 after PMSG stimulation.There was a marked decrease in ovarian weights in the experimental and the control group between days 4 and 7 after PMSG. Few necrotic cells were seen in corpora lutea on day 5, but many on day 6. All of them had disappeared on day 7. The number of ovaries with thrombi was 80-100% in both groups on day 4 and declined to approximately zero levels on day 7. The amount of thrombus formation appeared to be higher in the PGF2a-treated groups than in controls. Fibrinolytic activity was high in controls on day 3 and low in controls and in PGF2a-treated animals on day 4 after PMSG. It is concluded that (i) thrombus formation occurs in superstimulated ovaries during luteolysis; and (ii) thrombus formation is related to a decrease in fibrinolytic activity.

Five different phenotypes of endothelial cell cultures from the bovine corpus luteum: Present outcome and role of potential dendritic cells in luteolysis

“…The novel concept relies on many illustrations (Spanel-Borowski, 2011a) and is here heightened in details. Different fine-tuning of immunoresponses could explain why, in the hamster ovary, CLs completely disappear within one ovarian cycle (Spanel-Borowski and Heiss, 1986;Gaytán et al, 2001b), whereas regressing stages are seen for several cycles in ovaries of rats, cows and human. Luteal cysts and the persistence of a CL, which leads to a prolonged ovarian cycle, might be explained by immunemediated failure.…”