Short-term culture of peritoneum explants confirms attachment of endometrium to intact peritoneal mesothelium.
OBJECTIVE
To evaluate the initial adhesion of endometrium to the peritoneum.


METHODS
Descriptive study using light and confocal laser-scanning microscopy, immunohistochemistry, and transmission electron microscopy.


METHODS
University-based laboratory.


METHODS
Women without endometriosis undergoing surgery for benign conditions.


METHODS
None.


METHODS
Explants of peritoneum (n = 20), prepared from four patients, were cultured for 1 hour with mechanically dispersed proliferative or secretory endometrium. Peritoneum was cultured with endometrium from the same patient. Specimens were fixed and serially sectioned for hematoxylin and eosin stain, immunohistochemistry using an anti-cytokeratin monoclonal antibody, and transmission electron microscopy.


RESULTS
In 17 of 20 explants, endometrium was adherent to intact mesothelium. There was no evidence of transmesothelial invasion at any sites of attachment. Although in most cases endometrium was adherent to mesothelium via endometrial stroma, there were many sites of endometrial epithelium-mesothelium attachment. Confocal laser scanning microscopy demonstrated an intact monolayer of cytokeratin-positive cells below the sites of endometrial implantation. Transmission electron microscopy demonstrated intact, viable, mesothelial cells below sites of attachment.


CONCLUSIONS
This study demonstrates that endometrium rapidly adheres to intact peritoneal mesothelium. In addition, this study demonstrates that endometrial epithelial cells, as well as stroma, can attach to mesothelium. Further studies are needed that characterize the mechanism of endometrial-mesothelial cell adhesion.
Witz
C A
CA
Department of Obstetrics and Gynecology, Mail Code 7836, The University of Texas Health Science Center at San Antonio, 7730 Floyd Curl Drive, San Antonio, TX 78229-3900, USA. witz@uthscsa.edu
Thomas
M R
MR
Montoya-Rodriguez
I A
IA
Nair
A S
AS
Centonze
V E
VE
Schenken
R S
RS
D002448:Cell Adhesion; D004396:Coloring Agents; D046508:Culture Techniques; D004717:Endometrium / Q000648:ultrastructure; D004801:Eosine Yellowish-(YS); D004847:Epithelial Cells / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D006416:Hematoxylin; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D010537:Peritoneum / Q000648:ultrastructure; D017154:Stromal Cells / Q000648:ultrastructure
D004396:Coloring Agents; D007633:Keratins; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin