Increased cell proliferation in experimentally induced endometriosis in rabbits.
OBJECTIVE
To characterize the pattern of cell proliferation and apoptosis of eutopic and ectopic endometrium in rabbits after endometrium implantation for the experimental induction of endometriosis.


METHODS
Animal experimental study.


METHODS
Sector of experimental surgery.


METHODS
Twenty-female New Zealand rabbits.


METHODS
All animals underwent laparotomy for endometriosis induction by resection of one uterine horn, isolation of the endometrium, and fixation of tissue segment to the pelvic peritoneum. Two groups of 10 animals were sacrificed 4 and 8 weeks after endometriosis induction. The lesion was excised together with the opposite uterine horn for endometrial gland and stroma determination.


METHODS
Cell proliferation and apoptosis were determined in the eutopic and ectopic endometrium, and the cell proliferation index (CPI) and apoptotic index (AI) were calculated as the number of labeled cells per 1,000 cells. The tissue homeostasis index was the CPI/AI ratio. Glands and stroma were analyzed separately.


RESULTS
The CPI for ectopic tissue was increased compared with eutopic tissue, but there was no difference in the ectopic lesions between 4 and 8 weeks of induction. Considering only the AI, eutopic and ectopic endometrium did not differ after 4 weeks, but differed significantly in glandular tissue after 8 weeks. The tissue homeostasis index revealed cell proliferation in these tissues, with a CPI/AI more than 1.


CONCLUSIONS
Ectopic lesions seem to have a higher CPI than eutopic endometrium, with uncontrolled tissue growth occurring in induced endometriotic lesions.
Rosa-e-Silva
Julio Cesar
JC
Department of Gynecology and Obstetrics, University of São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil. juliocrs@convex.com.br
Garcia
Sergio Britto
SB
de Sá Rosa-e-Silva
Ana Carolina Japur
AC
Candido-dos-Reis
Francisco José
FJ
Poli-Neto
Omero Benedicto
OB
Ferriani
Rui Alberto
RA
Nogueira
Antonio Alberto
AA
D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D004195:Disease Models, Animal; D004715:Endometriosis / Q000473:pathology*; D004717:Endometrium / Q000473:pathology* / Q000637:transplantation; D005260:Female; D006706:Homeostasis; D011817:Rabbits; D017154:Stromal Cells / Q000473:pathology; D013997:Time Factors; D015854:Up-Regulation