ABSTRACT
There are some controversial data on application of progesterone and progesterone plus estrogen at luteal phase. To investigate the effects of different luteal support hormones on the Alkaline Phosphates [ALP] activity in the endometrial epithelium and endometrial thickness during superovulation process for obtaining the optimized endometrial receptivity in animal model. Pseudopregnant female Balb/c mice were induced for pseudopregnany through superovulation then the mice were divided into two groups. Experimental group included five groups: the pseudopregnant mice were given four consecutive, daily injections of progesterone [P group], estrogen [E group], estrogen + progesterone [E+P group], antiprogesterone + estrogen [RU 486 + E], and sham group. In the control group, pseudopregnancy was induced in the natural cycle. The uterus was collected after day 4.5 of pseudopregnancy. The samples were prepared for the morphological and morphometrical evaluation of the endometrial ALP activity and endometrial thickness. ALP activity was observed in all groups except P group. ALP activity of P + E group was similar to E and RU 486 + E groups. Sham group showed high ALP activity compared to the P group. The endometrial thickness was low in the P group and high in the sham group in comparison with other groups. In conclusion, super ovulation decreased the ALP activity. Estrogen along with progesterone at the luteal phase increased the enzyme activity and the endometrial thickness, compared with the progesterone administration, and thus, progesterone plus estrogen could improve embryo receptivity