Treatment whit aromatase inhibitors reduce the endometriotic lesions size in a murine model of endometriosis.

BILOTAS M; MERESMAN G; STELLA I; SUELDO C; BARAÑAO RI

Ciudad Autónoma de Buenos Aires, Argentina

Congreso; VII Jornadas Multidisciplinarias de la Sociedad Argentina de Biología.; 2005

Sociedad Argentina de Biología

TREATMENT WHIT AROMATASE INHIBITORS REDUCE THE ENDOMETRIOTIC LESIONS SIZE IN A MURINE MODEL OF ENDOMETRIOSIS. Bilotas M1, Meresman GF1, Sueldo C2, Barañao RI1. 1 Instituto de Biología y Medicina Experimental (IBYME) - CONICET y 2 Centro de Ginecología y Reproducción (CEGYR) - Buenos Aires.   Endometriosis (EDT) is considered to be an estrogen-dependent disease and recent studies shown that patients with EDT have high levels of aromatase P450 expression in the eutopic and ectopic endometrial tissue. Aromatase inhibitors, such as Letrozole (Let) and Anastrozole (Anas), are currently used in postmenopausal women to treat breast cancer, then the objective of this study was to evaluate the effect of Let and Anas as a possible treatment to reduce the endometriotic lesions (EDT-L). For this purpose we employed an experimental model of EDT in which we induced EDT-L by implanting autologous endometrial fragments in the mesothelium of Balb/c mice. A total of 48 female mice with inducing EDT were used, 18 of these that did not received treatment were used as controls (C), 14 were treated with a 10 µg/Kg daily dose of Let and 16 were treated with a 10 µg/Kg daily dose of Anas for 28 days beginning on day 1 post-induction of EDT. After treatment, animals were sacrificed and EDT-L were counted and measured (major diameter and thickness). Results were analyzed using One-way ANOVA (non-parametric) statistic test. Percentages of mice that develop EDT and the number of lesions founded per mouse were similar in all groups.  However the size of EDT-L  expressed as X ± S.E. was 43±25 mm3 in C, while in Let was  3.3±0.6 mm3 (p<0.001 vs C) and in Anas 8.3±1.4 mm3 (p<0.05 vs C). In conclusion, the treatment with aromatase inhibitors at the beginning of the disease did not inhibit the development of the lesions but produced a significant reduction in the size of EDT-L. This treatment for endometriosis could be a promising new modality that requires further investigation.