Progesterone receptors, oestrogen receptor α and glucocorticoid receptors in the bovine intercaruncular uterine wall around parturition

Abstract

The bovine intercaruncular uterine wall expresses steroid hormone receptors throughout pregnancy. Concentrations of specific hormones undergo massive changes during the peripartal period and modulate the synthesis of their own receptors. This is well documented for the placentome, but respective data concerning the intercaruncular uterine wall are completely lacking. Thus, intercaruncular uterine wall segments from cows (I) being 8 and 9 months pregnant (slaughtered cows) and (II) cows undergoing a premature caesarean section 269-282 days after artificial insemination (AI) with (IIa, b) or without (IIc) induction of birth with PGF(2alpha) agonist or (III) receiving a caesarean section during severe dystocia (n=6, 5, 5, 5, 6 and 4 animals, respectively) were studied. In four naturally calving cows (IV) endometrial biopsies were obtained within 30 min after the expulsion of the calf. All tissue probes were fixed for 24h in 4% formaldehyde, routinely embedded in paraffin, and cut at 4 microm. Progesterone receptors (PR), estrogen receptor alpha (ERalpha) and glucocorticoid receptors (GR) were assessed using specific antibodies and staining intensities were documented employing an immunoreactive score (IRS). PR, ERalpha and GR exhibited cell type- and location-specific distribution patterns. IRS for PR and ERalpha did not differ between groups. GR-IRS of endometrial stromal cells, however, were higher in animals undergoing premature caesarean section after induction of birth compared to animals slaughtered during month 8 or 9 of pregnancy or animals receiving caesarean section following dystocia. Results of the present study indicate that steroid hormone receptor amounts within the intercaruncular uterine wall do not (PR, ERalpha) - or in a tissue-specific manner (GR) only - change during the peripartal period, although respective hormones undergo massive changes during this period. This is in strict contrast to the placentome. Comparatively lower local tissue estrogen concentrations around term may be one cause for this difference.

Chlorpromazine Protects Against Apoptosis Induced by Exogenous Stimuli in the Developing Rat Brain

“…For assessment of immunohistochemical staining, the presence of any immunolabeled cells was considered to represent positive caspase-3 expression [8]. Total scores were calculated based on the SI using the following formula [9]: Total Scores = 1×n (SI1) +2×n (SI2) +3×n (SI3). A total of 81 sections were analyzed for cleaved caspase-3 immunostaining.…”

Immunohistochemical Demonstration of Vitamin D Receptor Distribution in Goat Intestines

“…The frequencies of the different staining intensities were assessed separately for each type of cell, were evaluated in each selected microscopic field and then expressed as the sum of positively stained cells of the respective type of cell. Immunoreactivities of the different cell types in the above-described locations were expressed using a score (immunoreactive score, VDR-IRS) that was calculated according to an equation used in a slightly modified version in other studies [Schäubli et al, 2006]:…”

Quantitative morphological changes in the interplacentomal wall of the gravid uterine horn of cattle during pregnancy

“…As evidenced by its expression of genes for many proteins, such as uterine milk proteins (UTMP) [ 25 ], glucose transporter-1 [ 26 , 27 ], calbindin D9k [ 28 , 29 ], transient receptor potential channel type 6 [ 29 ], MMP-2 and 9 [ 21 ], SOLD1 [ 30 ], TIMP-2 [ 21 ], EMMPRIN, an inducer of MMPs [ 31 ], galectins 3, 4, and 9 [ 32 ], and COX-2 [ 33 , 34 ], SE is involved in numerous functions during different phases of pregnancy, such as histiotrophic nourishment of the fetus, materno-fetal glucose and calcium transfer, endometrial restructuring, immunomodulation in favor of the fetus, and oxytocin-induced prostaglandin F2alpha production at term. The expression of receptors for estrogens [ 15 , 35 ] growth hormone [ 36 ], various elements of the IGF system [ 37 ], prostaglandins E and F2alpha [ 33 , 34 ], oxytocin [ 38 ] and glucocorticoids [ 15 , 35 ], sheds a light on various hormones and other factors of maternal and fetal origin influencing SE function during pregnancy. The lack of progesterone receptors in the SE during pregnancy is overcome by progesterone-sensitive subepithelial stromal cells producing paracrine-acting factors, such as growth factors [ 37 ], which in turn regulate SE function via their receptors expressed on SE and thus may also initiate SE hypertrophy and hyperplasia.…”

“…Secretions of EG, which are supplied with minimal amounts of progesterone receptors, or even completely lacking them, are activated and sustained via a servomechanism including progesterone-sensitive periglandular stromal cells producing paracrine factors, such as growth factors [ 2 , 37 , 45 ]. Estrogens, glucocorticoids [ 15 , 35 ], PGs E and F 2α [ 33 , 34 ] and growth hormone [ 36 ] directly regulate endometrial stromal function via their receptors. In this study, endometrial stroma Vv decreased significantly with ongoing pregnancy (67.2 vs. 37.0%), reflecting the five-fold increase in EG lumen Vv (8.2 vs. 40.1%).…”