scholarly journals Immunolocalization of progesterone receptors in the canine ovary and their relation to sex steroid hormone concentrations

Reproduction ◽  
2001 ◽  
pp. 73-83 ◽  
Author(s):  
H Vermeirsch ◽  
P Simoens ◽  
M Coryn ◽  
W Van den Broeck

The aim of the present study was to describe the normal cellular distribution of progesterone receptors in the canine ovary at different stages of the oestrous cycle. Samples of both ovaries were obtained from 75 healthy adult bitches of various breeds and ages, including five pregnant bitches and three bitches that had just delivered. The presence of progesterone receptors was visualized by immunohistochemistry on paraffin wax sections using a monoclonal antibody. Nuclear staining for progesterone receptors was observed in the surface epithelium, cortical tubules, rete ovarii, follicle cells, thecal cells, luteal cells, granulosa cell cords and ovarian stroma. The staining intensity for progesterone receptors in the follicle cells increased with the stage of follicle development, indicating an intrafollicular role of progesterone in the mechanism of ovulation and luteinization. The stronger staining intensities for progesterone receptors in thecal cells compared with follicle cells may be explained by the fact that thecal cells mediate some effects of steroid hormones on the follicle cells in secondary and tertiary follicles. Little correlation was found between the expression of progesterone receptors in follicle cells and oestradiol, progesterone or testosterone concentrations. This finding indicates a different regulating mechanism for progesterone receptors in canine ovarian follicles compared with other tissues of the genital tract. During pregnancy all groups of ovarian cells had lower staining intensity scores than during the oestrous cycle, although the sex steroid hormone concentrations in pregnant bitches were similar to those in non-pregnant bitches during the luteal phase of the oestrous cycle. The lower expression of progesterone receptors during pregnancy may be due to higher tissue concentrations of progesterone that are not reflected in the serum because of haemodilution and increased metabolism and clearance during pregnancy.

Reproduction ◽  
2001 ◽  
pp. 711-721 ◽  
Author(s):  
H Vermeirsch ◽  
P Simoens ◽  
M Coryn ◽  
W Van den Broeck

Androgens play an essential role as autocrine or paracrine agents in ovarian follicular growth, maturation and luteinization. The aim of this study was to describe the normal cellular distribution of androgen receptors in the canine ovary at different stages of the oestrous cycle. Samples of both ovaries were obtained from 34 dogs, including six pregnant animals and three that had just produced litters. Presence of androgen receptors was visualized by immunohistochemistry on paraffin wax sections using a polyclonal antibody. Nuclear staining for androgen receptors was observed in the surface epithelium, cortical tubules, rete ovarii, follicle cells, thecal cells, luteal cells, granulosa cell cords and ovarian stroma, indicating that androgens have important roles in ovarian function in bitches. In theca interna cells of tertiary follicles, androgen production seems to be more important than androgen receptivity, as immunostaining for androgen receptors in these cells was weak compared with that in other ovarian stromal cells. In primordial and primary follicles, the immunostaining for androgen receptors was rather weak, indicating that androgens are of minor importance in early preantral follicles. In follicle cells of larger preantral and antral follicles, the immunostaining for androgen receptors increased with the stage of the follicle. Corpora lutea expressed less immunostaining, which was not correlated with serum progesterone concentrations, although local actions of progesterone on androgen receptors in corpora lutea cannot be excluded. In general, few correlations were found between immunostaining for androgen receptors and serum sex steroid concentrations, indicating that other factors regulate androgen receptors in the canine ovary.


2002 ◽  
Vol 14 (4) ◽  
pp. 241 ◽  
Author(s):  
Hilde Vermeirsch ◽  
Wim Van Den Broeck ◽  
Mark Coryn ◽  
Paul Simoens

The aim of this immunohistochemical study was to describe the cellular distribution of the estrogen receptor-α (ERα), progesterone receptor (PR) and androgen receptor (AR) in canine uterine tubes. Samples of uterine tubes were taken from dogs in different stages of the estrous cycle, and dogs that were pregnant or had just delivered. Nuclear staining for sex steroid hormone receptors was observed in the surface epithelium, stromal cells and smooth muscle cells of the muscular layer. Only slight differences in staining pattern were observed between the ampulla and fimbriae. The staining for ERα and PR showed changes throughout the estrous cycle. Some of these changes were related to changing concentrations of sex steroid hormones. High staining scores for ERα and PR were found during proestrus and low scores during early metestrus. The staining for AR showed only minor cyclic changes. However, during proestrus and estrus, cytoplasmic staining for AR was observed in differentiated secretory epithelial cells, when nuclear staining in these cells was nearly absent. For the three hormone receptors, stromal cells generally stained with a higher intensity than epithelial cells. It is likely that many steroid hormone actions on the epithelium are mediated through stromal cells. During pregnancy, rather high staining scores were found for ERα and AR in the uterine tube. This is in contrast to observations in the canine pregnant uterus.


2002 ◽  
Vol 14 (4) ◽  
pp. 251 ◽  
Author(s):  
Hilde Vermeirsch ◽  
Wim Van Den Broeck ◽  
Paul Simoens

The aim of this immunohistochemical study was to describe the cellular distribution of the estrogen receptor-α (ERα), progesterone receptor (PR) and androgen receptor (AR) in canine vaginal and vulvar tissue. Samples were taken from dogs in different stages of the estrous cycle. Nuclear staining for ERα, PR and AR was observed in surface epithelium, stromal and smooth muscle cells. Receptors were also expressed in vulvar skin. Cytoplasmic staining for AR was observed in basal and parabasal cell layers of vulvar and vaginal epithelium. For all three receptors, staining intensity was generally higher in stromal cells compared with epithelial cells, suggesting that stromal cells may be more receptive to steroid hormone action. Therefore, as in other tissues of the female genital tract, stromal-epithelial interactions induced by sex steroid hormones may be of importance in canine vaginal and vulvar tissues. No cyclic changes in receptor immunostaining were observed. Significant positive correlations were found between receptor immunostaining in some vaginal and vulvar cell groups and the serum concentrations of estradiol-17β and testosterone, but not with the serum progesterone concentration. Significant negative correlations were found between ERα immunostaining in epithelial and stromal cells of the vagina and the serum estradiol-17α concentration, suggesting a negative feedback mechanism between estradiol-17β and its receptor. Both cell types play a role in the differentiation of vaginal epithelium, under the influence of estradiol-17β


2007 ◽  
Vol 86 (11) ◽  
pp. 1377-1384 ◽  
Author(s):  
Marie Westergren Söderberg ◽  
Bengt Johansson ◽  
Britt Masironi ◽  
Birgitta Byström ◽  
Christian Falconer ◽  
...  

Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5710-5720 ◽  
Author(s):  
Yoshinao Katsu ◽  
Kazumi Matsubara ◽  
Satomi Kohno ◽  
Yoichi Matsuda ◽  
Michihisa Toriba ◽  
...  

In many vertebrates, steroid hormones are essential for ovarian differentiation during a critical developmental stage as well as promoting the growth and differentiation of the adult female reproductive system. Although studies have been extensively conducted in mammals and a few fish, amphibians, and bird species, the molecular mechanisms of sex steroid hormone (estrogens) action have been poorly examined in reptiles. Here, we evaluate hormone receptor and ligand interactions in two species of snake, the Okinawa habu (Protobothrops flavoviridis, Viperidae) and the Japanese four-striped rat snake (Elaphe quadrivirgata, Colubridae) after the isolation of cDNAs encoding estrogen receptor α (ESR1) and estrogen receptor β (ESR2). Using a transient transfection assay with mammalian cells, the transcriptional activity of reptilian (Okinawa habu, Japanese four-striped rat snake, American alligator, and Florida red-belly freshwater turtle) ESR1 and ESR2 was examined. All ESR proteins displayed estrogen-dependent activation of transcription via an estrogen-response element-containing promoter; however, the responsiveness to various estrogens was different. Further, we determined the chromosomal locations of the snake steroid hormone receptor genes. ESR1 and ESR2 genes were localized to the short and long arms of chromosome 1, respectively, whereas androgen receptor was localized to a pair of microchromosomes in the two snake species examined. These data provide basic tools that allow future studies examining receptor-ligand interactions and steroid endocrinology in snakes and also expands our knowledge of sex steroid hormone receptor evolution.


Sign in / Sign up

Export Citation Format

Share Document