Although it is well established that the secretory activity of the corpus luteum absolutely depends on the presence of pituitary-derived luteinizing hormone (LH), it is unknown why the life span of the corpus luteum is extended during early pregnancy by the placental production of chorionic gonadotropin (CG) but regresses in the presence of LH despite the fact that CG and LH have similar action...

The rodent corpus luteum is an ephemeral structure releasing progesterone for only a few hours rather than several days. However, in response to the mating stimulus, sufficient prolactin is released from the pituitary gland in a unique pattern to activate the corpus luteum and maintain it in a secretory state for several days. Progesterone, secreted from the corpus luteum, prolongs the secretio...

Invasion of the corpus luteum by macrophages is a characteristic of luteal regression. Monocyte chemotactic protein-1 (MCP-1), a chemokine that recruits macrophages, is expressed in the rat corpus luteum where it increases in amount during luteolysis. In this study we examined the temporal and spatial expression of MCP-1 and changes in macrophage concentration in the human corpus luteum. Corpor...

The ovary not containing the corpus luteum was removed from each of fifty-two ewes on Day 8 of the cycle. These animals were then allocated to one of the following groups. Group 1 : (control) received no further treatment. Group 2: the contralateral uterine horn, i.e. located on the side opposite to the corpus luteum, was removed. Group 3 : the ipsilateral uterine horn, i.e. located on the same...

The cyclic nature of the capillary bed in the corpus luteum offers a unique experimental model to examine the life cycle of endothelial cells, involving discrete physiologically regulated steps of angiogenesis, blood vessel maturation and blood vessel regression. The granulosa cells and theca cells of the developing antral follicle and the steroidogenic cells of the corpus luteum produce and re...

We investigated, using an image analysis system, the immunohistochemical localization of leukocyte subpopulations and human leukocyte antigen (HLA)-DR in 30 normal-cycling human ovaries in order to better understand local immunological events in human ovaries. All subtypes of T lymphocytes examined (CD3+, CD4+ and CD8+ cells) were sporadically observed in the stroma and theca layers of follicle...

We examined the immunohistochemical localization of luteinizing hormone (LH)/human chorionic gonadotrophin (HCG) receptor (LH-R) in the human ovary using the anti-human LH-R monoclonal antibody, 3B5. In the antral follicles, LH-R was detected on theca interna cells. In pre-ovulatory follicles, granulosa cells also expressed LH-R. During corpus luteum formation, granulosa cells seemed to increas...