Research Abstract |
Female reproductive function is regulated by hypothalamic-pituitary-ovarian system. Pulsatile released gonadotropin-releasing hormone (GnRH) from hypothalamus stimulates the secretion of pituitary gonadotropins (FSH and LH) that not only induce ovarian follicle growth and ovulation but also produce ovarian steroid hormones (estrogen and progesterone) . The syntheses of these hormones are regulated each other through the feed-back mechanism. Abnormalities in this system causes ovulation disorders. In the patients with pituitary dysfunction, abnormalities in the following parts are speculated : 1) Response to GnRH (GnRH receptor), 2) Signal transduction after binding of GnRH to GnRH receptor, 3) Regulatory elements for gonadotropin gene expression, and 4) Gonadotropin genes. Thus, we tried to detect the causes of ovulation disorders by pituitary dysfunction in the present research project. Six female patients with ovulation disorders by pituitary dysfunction were prepared at Nagoya University Hospital. Lymphocytes were collected from the patients, and DNAs were extracted by guanidium method. Genes of GnRH receptor, LHbeta-subunit, and 300-bp upstream of gonadotropin alpha-subunit were amplified by PCR technic using these DNA as templates. The amplified DNA was cloned to plasmid through TA cloning and sequenced. As results, no abnormalities were found in the above genes in all the patients. Additionally, new findings in anomalous LH and relationship between structure and function of gonadotropin subnits were gotten. Moreover, gonadotropin effects to some gene expression in oocyte and granulosa cells and clinical significance of GnRH agonist were also studied.
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