The endometrial expression level of estrogen-α and VEGF-A in female rats administered with a low dose of estrogen in early clomiphene citrate therapy

The study was conducted to determine the effect of low-dose estrogen in the early cycle of clomiphene citrate therapy on the expression of level estrogen receptor α (ERα) and VEGF-A in the endometrium. This study was an experimental study using 29 adult female rats aged 3 months with the body weight of 150-200 grams. The female rats were randomly allocated were allocated randomly into 3 groups (C: placebo; T1: treated with clomiphene citrate (100 mg/kg BW, IP, single dose); T2: combination treatment with clomiphene citrate (100 mg/kg BW, IP, single dose) and estradiol valerate (15 pg/kg BW, IP, single dose). Uterine samples were examined for estrogen-α receptor expression and VEGF-A expression using immunohistochemistry. The results revealed a significant difference between the percentage of Estrogen-α in the C group compared with the T1 and T2 groups. Meanwhile, there was no significant difference between the T1 and T2 groups. The percentage of VEGF-A expression in group C was significantly different compared with T1 and T2. Meanwhile, there was no significant difference between the T1 and T2 groups. In conclusion, administration of a low dose of estradiol valerate in early clomiphene citrate therapy resulted in no significant effect on estrogen-α receptor expression and VEGF-A expression in the endometrium.