[Protein bcl-2 expression in the secretory endometrium after oral estrogen-progesterone replacement]

To compare the changes of the protein bcl-2 expression, regulatory mechanism in the process of apoptosis, in the secretory endometrium throughout natural and artificial (estrogen-progesterone substitution) cycles in the same group of patients.

A prospective study.

Dept. of Obstetrics and Gynecology, University Hospital Olomouc, Dept. of Histology and Embryology, Faculty of Medicine, Palacký University in Olomouc, Dept. of Obstetrics and Gynecology, Bata Hospital, Zlín.

Endometrial samples (n=56) were obtained on days 5 and 7 after ovulation, progesterone addition, resp. Patients (n=14) included in the study had regular menstrual cycle, age under 40, BMI range 20-32 and basal FSH level range 5-9 IU/l. The collected samples were processed routinely and bcl-2 was estimated by indirect three level imunohistochemic method.

We demonstrated the bcl-2 expression in all evaluated layers (epithelial surface, stroma, glands) of the mid-secretory endometrium in both cycles. No difference was found in bcl-2 expression between days 5 and 7 in the secretory phase of the natural cycle. In artificial cycles higher bcl-2 expression was found only in epithelial surface (p<0.05) between days 5 and 7. On day 7 higher bcl-2 expression was found in the artificial cycle in the endometrial epithelial surface (p<0.001) as well as in spongy layer (p<0.01) and compact layer (p<0.05) comparing to day 7 of the natural cycle.

The bcl-2 expression in the mid-secretory endometrium is significantly higher in the cycle with estrogen-progesterone substitution comparing to the natural cycle. These changes were more significant in endometrial and glandular epithelium than in stromal cells.