Influence of oestrogen and progesterone on macrophage distribution in the mouse uterus

Abstract

Macrophages are constituents of all normal connective tissue including the murine uterus. Macrophages have been identified previously in endometrium and myometrium of pregnant and non-pregnant murine uterus using antibodies against macrophages. In the current study immunohistochemical analysis of murine uterus demonstrated that there were not significant quantitative differences in uterine macrophages between the diestrous, pro-oestrous and oestrous stages. However, distributional changes occurred during the oestrous cycle. Macrophages were evenly distributed throughout uterine tissue during dioestrus, while, during pro-oestrus and oestrus, their concentration was highest in the subepithelial stroma. Because the oestrous cycle is hormonally regulated, we asked whether or not oestrogen and/or progesterone might influence macrophage distribution. Ovariectomy, which eliminates cyclical production of oestrogen and progesterone, resulted in a significant decrease in both the relative and the absolute number of uterine macrophages within 6 days. Injections of progesterone or oestrogen to ovariectomized mice resulted in restoration of uterine macrophage numbers. Injection of oestrogen plus progesterone in a regimen known to prepare the uterus for receptivity for blastocyst implantation increased the number of macrophages to levels which were consistently higher than those seen during oestrus. Moreover, following hormone administration macrophages were more concentrated in the subepithelial stroma, a distributional pattern which was most evident following injection of both hormones. The results suggest that both oestrogen and progesterone promote quantitative and distributional changes in the uterine macrophage population.

Estrogen and Angiogenesis

“…74,75 It is clear that sex steroids influence the recruitment of MPs, their function, 76 and their distribution in the uterus. 77 The relative roles of estradiol and progesterone have recently been clarified by studies revealing estradiol-mediated recruitment of MP, which is inhibited by progesterone 78 via its receptor. 79 Importantly, it has been noted that uterine inflammatory cells are the result of recruitment from the bloodstream rather than the result of local proliferation.…”

Macrophages regulate corpus luteum development during embryo implantation in mice

“…In the uterus, macrophages fluctuate in number and phenotype over the ovarian cycle, and additional macrophages are recruited into the endometrium in an inflammationlike response to seminal fluid during the pre-implantation period of early pregnancy (8,9). Uterine macrophages are implicated in remodeling processes and in inducing expression of epithelial glycoproteins associated with embryo attachment (10), and they potentially contribute to subsequent events of the uterine decidual response and placental trophoblast invasion (11).…”

Effects of estrogen receptor agonists on regulation of the inflammatory response in astrocytes from young adult and middle-aged female rats

“…Estrogen has been shown to affect inflammatory mediators such as cytokines in a number of systems and has been shown to decrease inflammation in experimental models of anterior uveitis (Miyamoto et al, 1999), carrageenan-induced pleurisy in the lungs (Cuzzocrea et al, 2001;Cuzzocrea et al, 2000) and adjuvant-induced arthritis (Badger et al, 1999). On the other hand, estrogen promotes prostatitis (Naslund et al, 1988), stimulates edema (Tchernitchin and Galand, 1983) and increases vascular permeability and influx of macrophages in the uterus (De and Wood, 1990;Kaushic et al, 1998). In central nervous system cells, estrogen pretreatment has been shown to attenuate LPS-induced superoxide release, phagocytic activity and an increase in iNOS (Bruce-Keller et al, 2000;Drew and Chavis, 2000;Vegeto et al, 2001;Vegeto et al, 2000) in microglial cells.…”