The Use Of A Third-generation Aromatase Inhibitor For Ovulation Induction And Its Influence To The Expression Of IGF-ⅠR MRNA And FSHR MRNA In The Mouse Ovary

【Object】To compare the effect of using a third-generation aromatase inhibitor letrozole(LE) with colmiphene citrate (CC) for ovulation induction in patients with polycystic ovary syndrome(PCOS), and the influences to serum concentration of E2 and LH.【Method】A total of 76 patients with PCOS were recruited from Dec 2005 to Jan 2007. Ovulation was induced using letrozole 2.5mg/day for 5 days starting from the third day of a spontaneous or progesterone-induced withdrawal bleeding, the other group using CC 50mg/day just from the same time for 5 days, too. From day 9, ultrasound scan was performed to monitor follicle development. When at least one of the diameter of the predominance follicles reached≥18mm, 10000 IU HCG was given intramuscularly to induce ovulation, then timed intercourse was advised after 36 hours. Observated the number and size of follicles, thickness of endometrium, cervical mucus score, serum level of LH and E2, calculated the pregnancy rate, miscarriage rate, multiple pregnancy rate and the happeness of ovarian hyperstimulation syndrome (OHSS).【Results】On the day of HCG administration , in the LE group, the number of mature follicles were less than that in the CC group, the difference was significant(p<0.05), the ovulation rate in the former group was a little higher than the latter one, but the difference was insignifican(tp>0.05). The cervical mucus score in the LE group was higher than that in the CC group(p<0.05),and the thickness of endometrium in the LE group was much thicker than that in the CC one(p<0.01). On the day of HCG administration, the average level of LH in the LE group was higher than that in the CC one; but the average level of E2 in the former one was lower in the latter one, the distinction was significan(tp<0.05). In all cycles, the pregnancy rate in the LE group was 15.49%, in the CC group was 10.26%, the difference was significan(tp<0.05); the miscarriage rate in the formerone was 20.0%,in the latter one was 25.0%, the difference ws insignificant(p>0.05).In the CC group, one occurred OHSS, one occurred multiple pregnancy, but in the LE group there were none. Among the patients with CC resistance who treated with LE, mature follicle rate was 53.8%, ovulation rate was 46.2%.【Conclusion】Letrozole is effective for the induction of ovulation in patients with PCOS, even to the CC resistant cases. LE has higher ovulation rate and pregnance rate than CC, and has little disadvantage to endometrium and cervical mucus, the cervical mucus scores were high, and endometrium were thick. Further investigation is needed to confirm if LE can be used as first line drug for ovulation induction. 【Object】To investigate the role of aromatase inhibitor letrozole(LE) on ovulation induction and its influence to the expression of IGF-ⅠR mRNA and FSHR mRNA, and the possible mechanisms.【Method】Divided sixty kunming mice which had regular estrus cycle into four groups, given different medicine from the pre-estrus period, calculated the follicle numbers in different groups, then used RT-PCR method to detected the expression of IGF-ⅠR mRNA,FSHR mRNA in different intervention groups.【Result】1 The average follicles in the LE/HMG/HCG group was greatest, the differences among the LE/HMG/HCG group,LE/HCG group and HMG/HCG group was significant(p<0.01). The average follicles in the LE/HCG group has significant differences from the HMG/HCG group(p<0.01).Follicles in the blank controlled group was lower than any medicine intervention group, the differences among them was significant(p<0.01).2 The expression ofβ-actin mRNA and IGF-ⅠR mRNA were detected in all groups tissues;the expression of FSHR mRNA was detected in LE-used groups ,the expression rate in HMG/HCG group was 86.7%(13/15),the blank controlled group was 73.3%(11/15). The relative express intensity of IGF-ⅠR mRNA,FSHR mRNA in four groups were different (p<0.05); the comparison between each two groups was :LE/HMG/HCG was highest, LE/HCG group was secondly, then was HMG/HCG group, the blank controlled group was lowest.【Conclusion】LE can enhance the expression of IGF-ⅠR mRNA and FSHR mRNA in the mouse ovary, can promote the development of follicles.