Actions of prostaglandin F-2 alpha and prolactin on intercellular adhesion molecule-1 expression and monocyte/macrophage accumulation in the rat corpus luteum
Expression of intercellular adhesion molecule-1 (ICAM-1) and the accumulation of monocytes/macrophages are inflammatory events that occur during PRL (PRL)-induced regression of the rat corpus luteum. Here we have compared the ability of prostaglandin F-2 alpha (PGF) and PRL to induce, in rat corpora lutea, inflammatory events thought to perpetuate luteal regression. Immature rats were ovulated with eCG-hCG and then hypophysectomized (Day 0), which resulted in a single cohort of persistent, functional corpora lutea. On Days 9-11, the rats received twice daily injections of saline, PGF (Lutalyse, 250 mug/injection), or PRL (312 mug/injection) to induce luteal regression. Surprisingly, luteal weight and plasma progestin concentrations (progesterone and 20 alpha -dihydroprogesterone) did not differ between PGF-treated rats and controls; whereas both luteal weight and plasma progestins declined significantly in PRL-treated rats. Furthermore, corpora lutea of PGF-treated rats and controls contained relatively minimal ICAM-1 staining and few monocytes/macrophages. In contrast, but as expected, corpora lutea of PRL-treated rats stained intensely for ICAM-1 and contained numerous monocytes/macrophages. In an additional experiment, there was no indication that luteal prostaglandin F-2 alpha receptor mRNA diminished as a result of hypophysectomy. These findings suggest that prolactin, not PGF, induces the inflammatory events that accompany regression of the rat corpus luteum.
Biology of reproduction
Society for the Study of Reproduction
Digital Object Identifier (DOI)
Olson, Kristen K.; Anderson, Lori E.; Wiltbank, Milo C.; and Townson, David H., "Actions of prostaglandin F-2 alpha and prolactin on intercellular adhesion molecule-1 expression and monocyte/macrophage accumulation in the rat corpus luteum" (2001). Biology of reproduction. 18.
© 2001 by the Society for the Study of Reproduction, Inc.