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Is estradiol mandatory for an adequate follicular and embryo development? A mouse model using aromatase inhibitor (anastrozole)

  • Animal Experimentation
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Abstract

Background: Although high levels of estradiol are found in the follicular fluid, little is known about its necessity for adequate follicular growth, oocyte maturation and embryo development. Arimidex (anastrozole) is a potent aromatase inhibitor capable to induce an in-vivo milieu deprived of estradiol. This study uses a mouse model applying Arimidex to create an in-vivo system lacking of estradiol, in order to explore whether this gonadal steroid hormone is mandatory for folliculogenesis followed by normal fertilization and embryo development.

Methods: Experiment 1: Immature C57 Black female mice, aged 3–4 weeks were superovulated by 5 IU PMSG given intraperitoneally. A study group (9 mice) was concomitantly injected with 0.1 mg of Arimidex intraperitoneally given the morning day before PMSG, the morning day of PMSG injection and the following two days. The control group (8 mice) was similarly injected with normal saline. Estradiol (E2) and progesterone (P) serum levels were tested 48 hours after PMSG and the ovaries of each mouse blindly examined by a pathologist to evaluate follicular development. Experiment 2: 48 h after PMSG superovulation, hCG (7.5 IU) was injected intraperitoneally, followed by mating. The study group was treated with Arimidex 0.1 mg intraperitoneally daily from a day prior to PMSG injection to the day of sacrifice. The control group was treated similarly by normal saline. Forty-two hours after mating blood was withdrawn for E2 and P levels followed by tubal dissection. Embryos of 2–4 cells were cultured in-vitro and the development to the morula, blastocyst and hatching blastocyst stages were examined 24, 42, and 48 h later.

Results: Experiment 1: A significant reduction of E2 levels was achieved in the Arimidex group in comparison to control group (126.3±104.8 and 1910±960 pmol/L, respectively; < 0.0001). Nevertheless, the two groups did not differ by the mean number of follicles (27±9.5 and 30.4±13.0) or the distribution for antral (65% and 68.4%) and pre-antral (35% and 31.6%) follicles, respectively. Experiment 2: The reduction of estradiol during follicular phase did not hamper follicular development, in-vivo fertilization and in-vitro embryo development. Similar rates of embryo development to the morula stage (90.6% and 86%), blastocyst stage (86% and 89%) and hatching blastocyst (81% and 78%) were achieved in the Arimidex group and the control group, respectively.

Conclusions: Adequate folliculogenesis is independent of estrogen but is conditioned on gonadotropin stimulation. Moreover, depletion of estradiol in the vicinity of the oocyte did not impair its developmental potential, including its fertilization and development into morulae, blastocysts and hatching blastocysts.

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References

  1. Hillier SG. Ovarian manipulation with pure gonadotropins. J Endocrinol 1990;127:1–4.

    PubMed  CAS  Google Scholar 

  2. Wu TC, Wang L, Wan YJ. Detection of estrogen receptor messenger ribonucleic acid in human oocytes and cumulus-oocyte complexes using reverse transcriptase-polymerase chain reaction. Fertil Steril 1993;59:54–9.

    PubMed  CAS  Google Scholar 

  3. Couse JF, Lindzey, Grandrian K, Gustafsson JA, Korach KS. Tissue distribution and quanitative analysis of estrogen receptor-α (ERα) and estrogen receptor-β (ERβ) messenger ribonucleic acid in the wild wild type and ER-α knockout mouse. Endocrinollogy 1997;138:4613–21.

  4. Tremblay GB, Tremblay A, Copeland NG, Gilbert DJ, Jenkins NA, Labrie F, Giguere V. Cloning, chromosomal localization and function analysis of the murine estrogen receptor B. Mol Endocrinol 1997;11:353–65.

    Article  PubMed  CAS  Google Scholar 

  5. Dukes M, Edwards PN, Large M, Smith IK, Boyle T. The preclinical pharmacology of “Arimidex” (Anastrozole;ZD1033)- a potent, selective aromatase inhibitor. J Steroid Biochem Molec Biol 1996;58:439–45.

    Article  PubMed  CAS  Google Scholar 

  6. Meirow D, Schenker JG, Rosler A. Ovarian hyperstimulation syndrome with low estradiol in non-classical 17 alpha-hydroxylase 17, 20-lyase deficiency: what is the role of estrogens? Hum Reprod 1996;11:2119–21.

    PubMed  CAS  Google Scholar 

  7. Pellicer A, Miro F, Sampaio M, Gomez E, Bonilla-Musoles FM. In-vitro fertilization as a diagnostic and therapeutic tool in a patient with 17, 20-desmolase deficiency. Fertil Steril 1991;55:970–5.

    PubMed  CAS  Google Scholar 

  8. Rabinovici J, Blankstein J, Goldman B, Rudak E, Dor Y, Pariente C, Geier A, Lunenfeld B, Mashiach S. In-vitro fertilization and primary embryonic cleavage are possible in 17 alpha hydroxylase deficiency despite extremely low intrafollicular 17 beta-estradiol. J Cl Endocrinol Metabol 1989;68:693–7.

    Article  CAS  Google Scholar 

  9. Conte FA, Grumbach MM, Ito Y, Fisher CR, Simpso ER. A syndrome of female pseudohermaphordism, hypergonadotropic hypogonadism, and multicystic ovaries associated with missense mutations in the gene encoding aromatase (p450arom). J Clin Endocrinol Metab 1994;78:1287–92.

    Article  PubMed  CAS  Google Scholar 

  10. Morishima A, Grumbach MM, Simpson ER, Fisher C, Qin K. Aromatase deficiency in male and female siblings caused by a novel mutation and the physiological role of estrogens. J Cl Endocrinol Metab 1995;80:3689–98.

    Article  CAS  Google Scholar 

  11. Rosenfeld CS, Murray AA, Simmer G, Hufford MG, Smith MF, Spears N, Lubahn DB. Gonadotropin induction of ovulation and corpus loteum formation in young estrogen receptor-knockout mice. Biolo Reprod 2000;62:599–605.

    Article  CAS  Google Scholar 

  12. Krege JH, Hodgin JB, Couse JF, Enmark E, Warne M, Mahler JF, Sar M, Korach KS, Gustafsson JA, Smithies O. Generation of reproductive phenotypes of mice lacking estrogen receptor-beta. Proc Natl Acad Sci USA 1998;95:15677–82.

    Article  PubMed  CAS  Google Scholar 

  13. Selvaraj N, Shetty G, Vijayalakshmi K, Bhatnagar AS, Moudgal NR. Effect of blocking oestrogen synthesis with a new generation aromatase inhibitor CGS 16949A on folliculr maturation induced by pregnant mare serum gonadotropin in the immature rat. J Endocrinol 1994;142:563–70.

    Article  PubMed  CAS  Google Scholar 

  14. Zelinski-Wooten MB, Hess DL, Baughman WL, Molskness TA, Wolf DP, Stouffer RL. Administrasion of an aromatase inhibitor during the late follicular phase of gonadotropin-treated cycles in rhesus monkeys: effects on follicular development, oocyte maturation, and subsequent luteal function. J Clin Endocrinol Metabol 1993;76:988–95.

    Article  CAS  Google Scholar 

  15. Moudgal NR, Shetty G, Selvaraj N, Bhatnagar AS. Use of sepecific aromatase inhibitor for determining wether there is a role for oestrogen in follicle/oocyte maturation, ovulation and preimplantation embryo development. J Reprod Fertil Suppl 1996;50:69–81.

    PubMed  CAS  Google Scholar 

  16. Hu, Y, Cortrrindt R, Smitz J. Effects of aromatase inhibition on in vitro follicle and oocyte development analyzed by early preantral mouse follicle culture. Mol Reprod Dev 2002;61:549–59.

    Article  PubMed  CAS  Google Scholar 

  17. Fisher CR, Graves KH, Parlow AF, Simpson ER. Characterization of mice deficient in aromatase (ArKO) because of targeted disruption of the cyp19 gene. Proc Natl Acad Sci USA 1998;95:6965–70.

    Article  PubMed  CAS  Google Scholar 

  18. Britt KL, Drummond AE, Cox VA, Dyson M, Wreford NG, Jones ME, Simpson ER, Findlay JK. An age related ovarian phenotype in mice with targeted disruption of the Cyp19 (aromatase) gene. Endocrinology 2000;141:2614–23.

    Article  PubMed  CAS  Google Scholar 

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Correspondence to Muhammad Fatum.

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Fatum, M., Gyo, Y., Diana, P. et al. Is estradiol mandatory for an adequate follicular and embryo development? A mouse model using aromatase inhibitor (anastrozole). J Assist Reprod Genet 23, 407–412 (2006). https://doi.org/10.1007/s10815-006-9089-2

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  • DOI: https://doi.org/10.1007/s10815-006-9089-2

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