Immunocytochemical localization and changes in endometrial progestin receptor protein during the porcine oestrous cycle and early pregnancy

1994 ◽  
Vol 6 (6) ◽  
pp. 749 ◽  
Author(s):  
RD Geisert ◽  
TN Pratt ◽  
FW Bazer ◽  
JS Mayes ◽  
GH Watson

Changes of progesterone receptor (PR) protein and cellular localization in the endometrium were evaluated during the oestrous cycle and early pregnancy of the gilt. During the oestrous cycle, the concentration of total PR protein within the endometrium was highest on Days 0-5 and decreased on Day 10. The endometrial concentration of PR reached a nadir on Day 12 and this level was maintained throughout the remainder of the oestrous cycle (Day 18). In pregnant gilts, the concentration of endometrial PR protein from Day 10 to Day 18 was similar to that in cyclic gilts. Western blot analysis with antiserum specific for the A and B isoforms of PR indicated that porcine endometrium expresses both isoforms of PR. Immunostaining was detectable for both the A and B isoforms of PR from Day 0 to Day 12 of the oestrous cycle. However, no staining was observed on Day 15 and Day 18 of the oestrous cycle or pregnancy Immunocytochemical localization of PR in the endometrium of cyclic gilts and pregnant gilts indicated that there was intense staining for PR in surface epithelium and glandular epithelium during oestrus (Day 0) and on Day 5. However, the staining was less intense on Day 7 and Day 10 of the oestrous cycle and no epithelial staining was observed after Day 12. PRs were present in the stroma and myometrium throughout the oestrous cycle and early pregnancy. The presence of conceptuses during pregnancy did not affect the loss of PR from the uterine epithelium after Day 10 of gestation. Down-regulation of epithelial PR might be one factor involved in the timing of luteolysis during the oestrous cycle as well as conceptus growth and placentation during early pregnancy.

1993 ◽  
Vol 5 (5) ◽  
pp. 531 ◽  
Author(s):  
DH Dubois ◽  
LC Smith ◽  
FW Bazer

Experiments examined the characteristics and activity of phospholipase A2 (PLA2) and examined the presence of immunoreactive cyclooxygenase in endometrium of pigs during the oestrous cycle and early pregnancy. Endometrial PLA2 was calcium-independent and activity of the enzyme was greatest at a pH of 8.0. Activity of PLA2 on Days 10, 12, 14 and 16 of the oestrous cycle did not differ (P > 0.1) from activity on those days during pregnancy. During oestrus and early metoestrus (Days 0-3), cyclooxygenase was present in both glandular and surface epithelium. After Day 10 of the oestrous cycle or pregnancy, staining for cyclooxygenase was less intense in the lower and middle uterine glands. However, the upper glandular epithelium near the surface epithelium stained intensely. By Day 15 of the oestrous cycle or pregnancy, intense staining for cyclooxygenase appeared restricted to the upper uterine glands. These results indicate changes in localization of immunoreactive cyclooxygenase throughout the oestrous cycle and suggest that these are not related to altered secretion of prostaglandins (PGs) during early pregnancy. The stimulatory effects of porcine conceptus products on secretion of PGs during early pregnancy are apparently not associated with increased activity of endometrial PLA2.


Reproduction ◽  
2005 ◽  
Vol 129 (3) ◽  
pp. 349-359 ◽  
Author(s):  
S Sukjumlong ◽  
A-M Dalin ◽  
L Sahlin ◽  
E Persson

Physiological changes in the sow uterus involve the regulation by progesterone and its receptor proteins (PR). Therefore, the aim of the present study was to investigate the localization of PR during different stages of the oestrous cycle and in inseminated sows during early pregnancy by use of immunohistochemistry. Uterine samples were collected from cyclic and inseminated sows at different stages of the oestrous cycle and early pregnancy. The samples were fixed in 10% formaldehyde and embedded in paraffin. Immunohistochemistry was done by use of a mouse monoclonal antibody to PR. The highest PR immunostaining in the surface epithelium was observed at oestrus/5–6 h after artificial insemination (AI) and early dioestrus/70 h after AI. In the glandular epithelium, the highest level of PR was found at oestrus with the lowest at late dioestrus/d 19. Higher levels of PR were observed in inseminated groups compared with cyclic sows. In the myometrium, a high level of PR was found at oestrus, while stromal PR cells were constantly present throughout the oestrous cycle and at different stages of early pregnancy. In conclusion, this study shows that the immunopresence of PR in the sow uterus differed between uterine compartments at the same reproductive stage. Differences were also found for some uterine compartments between cyclic and inseminated/early pregnant sows. The relatively consistent immunostaining of PR in the stroma strengthens a stromal role in the regulation of physiological activities in the sow uterus during the oestrous cycle as well as early pregnancy.


1990 ◽  
Vol 2 (4) ◽  
pp. 311 ◽  
Author(s):  
LA Salamonsen ◽  
JK Findlay

Prostaglandin (PG) synthase has been localized by immunocytochemistry within the ovine uterus throughout the oestrous cycle and in early pregnancy. On Day 4 of the cycle, PG synthase was located primarily in the stromal cells in caruncular and intercaruncular tissue with little staining in the epithelium. On Days 14 through to 16, the most intense staining was in the luminal epithelial cells (caruncular and intercaruncular) and in epithelial cells of glands close to the uterine lumen. PG synthase was also located in the intercaruncular stromal cells, particularly close to the myometrium. Staining for the enzyme on Day 10 was intermediate between that of Day 4 and Day 14. On Day 15 of pregnancy, the pattern of staining was identical to that on Day 15 of the cycle, with no detectable difference in intensity. When endometrial cells (cycle, Day 14) were cultured with and without ovine trophoblast protein-1 (3 ng mL-1) in vitro, release of PGE and PGF2 alpha was attenuated (54% and 47% of control respectively) but no differences were observed in the intensity of staining for PG synthase in the cells. These results demonstrate marked cyclical changes in the endometrial cell types producing PGs, suggesting differential regulation of PG synthase. In addition, it appears that conceptus-induced changes in PGF2 alpha release do not occur via changes in the concentration or cellular localization of PG synthase, but rather that the activity of the enzyme is modified.


1993 ◽  
Vol 5 (3) ◽  
pp. 247 ◽  
Author(s):  
RD Geisert ◽  
RM Brenner ◽  
RJ Moffatt ◽  
JP Harney ◽  
T Yellin ◽  
...  

Conceptus secretion of oestrogen on Day 11 of gestation is involved with establishment of pregnancy in the pig. Changes in oestrogen receptor (ER) protein, mRNA and cellular localization in the endometrium were evaluated during the oestrous cycle and early pregnancy of the gilt. In nonpregnant gilts, concentration of nuclear ER in the endometrium increased from Days 0 to 12 followed by a decline on Day 15 of the oestrous cycle. In pregnant gilts, changes in endometrial nuclear ER during Days 10, 12, 15 and 18 were similar to that in cyclic pigs. Analysis of endometrial ER mRNA expression did not detect any difference between cyclic and pregnant pigs between Days 10 and 15 postoestrus. Expression of ER mRNA in endometrium of cyclic and pregnant gilts was greatest on Day 10 followed by a decline on Day 15. Endometrial ER mRNA increased on Day 18 of the oestrous cycle, but remained low during pregnancy. Immunocytochemical localization of ER in the endometria of cyclic and pregnant gilts indicated that there was intense staining for ER in stromal cells and moderate to strong staining in surface and glandular epithelial cells during oestrus (Day 0) and Day 18 of the oestrous cycle. However, stromal ER staining was absent from Days 5 to 15 of the oestrous cycle and continued to be suppressed on Day 18 of pregnancy. Immunocytochemical staining of ER in the surface and glandular epithelium was readily detectable from Days 0 to 12 of the oestrous cycle and during pregnancy. Intensity of staining for ER declined in surface epithelial cells on Day 15 in both cyclic and pregnant pigs whereas positive staining for ER in glandular epithelium was absent. Staining for ER on uterine surface epithelial cells increased during pro-estrus (Day 18) of cyclic gilts but remained similar to Day 15 in pregnant gilts. Changes in endometrial ER protein, mRNA and localization in surface epithelium are consistent with a physiological role for conceptus oestrogen secretion in uterine function and maternal recognition of pregnancy in the pig.


Reproduction ◽  
2000 ◽  
pp. 217-223 ◽  
Author(s):  
ML Mariani ◽  
M Souto ◽  
MA Fanelli ◽  
DR Ciocca

Certain heat shock proteins are regulated by steroid hormones and are associated with oestrogen receptor function in reproductive tissues, indicating that these proteins have a role during implantation, decidualization and placentation. In the present study, the expression of hsp25, hsp70 and oestrogen receptor alpha were examined by immunohistochemistry in oviducts from rats during neonatal development, the oestrous cycle and during early pregnancy. Oestrogen receptor alpha was the first protein observed in the neonatal oviduct, and its expression preceded that of hsp70 and hsp25. Although these heat shock proteins have been associated with the oestrogen receptor, this study showed that during early development of the oviduct, the receptor protein was not associated with the concomitant expression of hsp25 and hsp70. However, these heat shock proteins were expressed when oviductal cells became differentiated. In the adult oviduct, hsp70 was more abundant than hsp25, moreover, there were no significant modifications in expression of hsp25 during the oestrous cycle. In contrast, the expression of hsp70 was significantly higher in epithelial cells during dioestrus, when the maximum amount of oestrogen receptor alpha was also observed. Therefore, the present study shows that hsp70, but not hsp25, is an oviductal protein modulated by the oestrous cycle and that it is a protein marker for specific phases of the oestrous cycle. In addition, hsp70 was more responsive to the hormonal changes in the infundibulum and ampullar regions of the oviduct. During early pregnancy, hsp25 expression was downregulated (unlike in the endometrium), whereas hsp70 was relatively abundant in the oviduct. hsp70 was observed in all functional segments of the oviduct during pregnancy, indicating that in the oviduct, this protein is modulated by oestrogens and progesterone and possibly by other pregnancy-related hormones.


1997 ◽  
Vol 9 (4) ◽  
pp. 395 ◽  
Author(s):  
Rodney D. Geisert ◽  
Robert M. Blair ◽  
Thea Pratt ◽  
Michael T. Zavy

Cathepsin L has been proposed to be involved with the endothelial–chorial type of placentation in the cat. Little information concerning the presence and secretion of cathepsin L is available for a species with noninvasive epitheliochorial placentation such as the pig. Cathepsin L activity in uterine flushings and endometrium from gilts during different days of the oestrous cycle and early pregnancy was analysed through specific substrate metabolism and Western blot analyses with antiserum against cat endometrial cathepsin L. This antiserum was utilized to determine the cellular localization of the enzyme within porcine endometrium. Cathepsin L activity within uterine flushings was elevated on Day 15 of the oestrous cycle and early pregnancy, with activity declining on Day 18. Cat cathepsin L antiserum cross-reacted with a group of 46, 40 and 38 kDa uterine proteins and detected a product within the surface and glandular epithelium of the endometrium. The appearance of the 40 kDa protein was first detected on Day 10 of the oestrous cycle with the 38 kDa proteins appearing on Day 15 and 18 of pregnancy. The 40 and 38 kDa uterine proteins appear to be steroid regulated as 12 days of progesterone administration is necessary to detect the proteins and cathepsin L activity.


1996 ◽  
Vol 8 (5) ◽  
pp. 843 ◽  
Author(s):  
TE Spencer ◽  
MA Mirando ◽  
JS Mayes ◽  
GH Watson ◽  
TL Ott ◽  
...  

The effects of recombinant ovine interferon-tau (IFN-tau) and progesterone on oestrogen-stimulated expression of endometrial receptors for oestrogen (ER), progesterone (PR) and oxytocin (OTR) were determined in ovariectomized ewes. Cyclic ewes (n = 16) were ovariectomized and fitted with uterine catheters on Day 4 of the oestrous cycle (Day O, oestrous) and assigned randomly in 2 x 2-factorial arrangement to receive daily intrauterine injections of either recombinant ovine IFN-tau (roIFN-tau; 2 x 10(7) anti-viral units) or control proteins from Day 11 to Day 15 and 50 mg progesterone from either Day 4 to Day 10 (E-P) or Day 4 to Day 15 (E+P). All ewes received 50 micrograms oestradiol-17 beta on Days 13, 14 and 15 and were hysterectomized on Day 16. In control ewes, endometrial ER mRNA, PR protein and OTR density were greater in E-P- than E+P- treated ewes. In E-P ewes, roIFN-tau decreased oestrogen-stimulated increases in ER and OTR, but not PR expression compared with control ewes. In E+P ewes, endometrial ER mRNA and protein, PR mRNA and protein, and OTR levels were lower in roIFN-tau-treated ewes than control ewes. Immunoreactive ER and PR were absent in the endometrial luminal and superficial glandular epithelium of roIFN-tau compared with control ewes, but were present in the deep glandular epithelium and stroma regardless of steroid or protein treatment. These results indicate that progesterone affects oestrogen-induced increases in endometrial ER, PR and OTR expression in the PR+ deep glandular epithelium and stroma, whereas IFN-tau suppresses oestrogen-induced increases ER, PR and OTR expression in the PR- luminal and superficial glandular epithelium. These combined actions of IFN-tau and progesterone to suppress oestrogen-induced increases in endometrial OTR formation would prevent pulsatile production of luteolytic prostaglandin F2 alpha by the endometrium during early pregnancy.


1980 ◽  
Vol 87 (3) ◽  
pp. 365-373 ◽  
Author(s):  
LESLIE MYATT ◽  
M. G. ELDER ◽  
LOUIS LIM

The binding characteristics, content and intracellular distribution of cytosolic and nuclear progesterone receptors have been investigated, using [3H]progesterone as ligand, in the rat uterus bearing a unilateral intra-uterine device (IUD) during the oestrous cycle and from days 3 to 6 of pregnancy. The dissociation constants of nuclear and cytosolic progesterone–receptor complexes for IUD-containing and control uterine horns were similar. Cytosolic receptor concentrations in the IUD-containing uterus were always lower but changed in a manner similar to the control during the periods studied. Nuclear receptor concentrations in the control horn reflected changes in hormone levels during the oestrous cycle although concentrations measured were greater than previously reported. However, in IUD-containing uteri the pattern was completely reversed with minimal levels at pro-oestrus. Nuclear receptor concentrations were little different in both horns during early pregnancy. Total progesterone receptor synthesis determined between metoestrus and pro-oestrus in IUD-containing horns was significantly less than that of control horns. This correlated with the attenuated rise of nuclear oestrogen receptor levels previously observed between these times in IUD-containing uterine horns.


Reproduction ◽  
2001 ◽  
pp. 965-979 ◽  
Author(s):  
RS Robinson ◽  
GE Mann ◽  
GE Lamming ◽  
DC Wathes

This study examined the expression patterns of oxytocin and steroid receptors in the bovine endometrium during the oestrous cycle and early pregnancy to elucidate their respective roles in the regulation of luteolysis and the maternal recognition of pregnancy. In Expt 1, uterine biopsies were collected from four cows throughout three oestrous cycles each, to provide daily samples. In Expt 2, uterine tissue was collected on days 12, 14, 16 and 18 of the oestrous cycle (n = 20) or early pregnancy (n = 16). Oxytocin receptor, oestrogen receptor alpha and progesterone receptor mRNAs were localized by in situ hybridization, and localization of oestrogen receptor and progesterone receptor was confirmed by immunocytochemistry. All three receptors showed time- and cell-specific expression patterns. Oestrogen receptor alpha increased in all regions at oestrus but high concentrations were also found in the luminal epithelium during the mid-luteal phase and in the deep glands throughout the oestrous cycle. Progesterone receptor expression was higher in the stroma than it was in the types of epithelial cell, and increased expression was observed at oestrus and during the early luteal phase. The cyclical upregulation of oxytocin receptors in the luminal epithelium on about day 16 was not related to preceding changes in the endometrial expression of either oestradiol alpha or progesterone receptors. During early pregnancy, oxytocin receptor expression was suppressed. Oestrogen receptor a concentrations increased in the non-pregnant cows and decreased in the pregnant cows between days 16 and 18, but these changes followed rather than preceded the upregulation of oxytocin receptors in the non-pregnant cows. It is concluded that the initial upregulation of oxytocin receptors in the luminal epithelium, which triggers luteolysis, is not associated directly with changes in expression of oestrogen receptor alpha.


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