Formation of pinopodes in human endometrium is associated with the concentrations of progesterone and progesterone receptors.
OBJECTIVE
To investigate the relation between the development of endometrial pinopodes and the serum concentration of hormones and the distribution of estrogen receptor-alpha, estrogen receptor-beta, progesterone receptor A, and progesterone receptor B.


METHODS
Prospective clinical study.


METHODS
Hospital-based unit of reproductive health and university-affiliated reproductive research laboratories.


METHODS
Twenty-seven healthy fertile women with normal menstrual cycles.


METHODS
Urine and blood sampling for hormone measurement, vaginal ultrasonography, and endometrial biopsy.


METHODS
Appearance of the endometrium on light microscopy, pinopode formation, serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), and expression of progesterone receptors A and B and estrogen receptors alpha and beta.


RESULTS
Pinopode formation and regression were closely associated with increases and decreases, respectively, in serum progesterone concentration. At pinopode development, levels progesterone receptors A and B in the glandular and luminal epithelial cells decreased; this effect was mainly dependent on the absence of progesterone receptor B. Serum estrogen levels and levels of estrogen receptor alpha and beta did not correlate with pinopode formation.


CONCLUSIONS
The increase in serum progesterone level and down-regulation of progesterone receptor B are important in development of pinopodes.
Stavreus-Evers
A
A
Division for Reproductive Endocrinology, Department of Woman and Child Health, Karolinska Hospital, Huddinge, Sweden. anneli.strsvreus-evers@kbh.ki.se
Nikas
G
G
Sahlin
L
L
Eriksson
H
H
Landgren
B M
BM
D000328:Adult; D010064:Embryo Implantation / Q000502:physiology*; D004717:Endometrium / Q000502:physiology* / Q000648:ultrastructure*; D004958:Estradiol / Q000097:blood; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D006801:Humans; D009994:Osmolar Concentration; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C101118:progesterone receptor A; C097314:progesterone receptor B; D011374:Progesterone; D004958:Estradiol