Abstract
The present study was designed to investigate the effects of gonadotrophins on in vitro growth and maturation in mouse preantral follicles. Ovaries were removed from 12-day-old ICR mice. Follicles were dissociated enzymetically in Leibovitz L-15 medium containing 1 mg/$m\ell$ collagenase and 0.2 mg/$m\ell$ DNase I. The follicles were cultured on Transwell-COL membrane inserts in six well cluster dishes for 10 days. The culture medium was $\alpha$MEM medium supplemented with 5% fetal bovine serum and FSH or HMG. After 10 days of growth in vitro, follicles were allowed to mature for 18~20 hr in medium supplemented with 1.5 IU/$m\ell$ hCG. The oocytes were then denuded of their cumulus cells and assessed maturation status. Concentrations of oestradiol and progesterone were measured with a radioimmunoassay. Oocyte diameter was determined with an ocular micrometer. The survival and Metaphase II rates of oocytes were significantly higher in FSH treatment groups than in control group (P＜0.001), but there were no differences among the groups of treated FSH concentration. The survival and Metaphase II rates of oocytes in HMG treatment group (60.9 and 40.6%) were higher than in FSH treatment group (76.6 and 48.2%) and control group (49.2 and 7.1%). The survival and Metaphase II rates of oocytes on both FSH and LH treatment groups were no differences among the ratios of FSH and LH. Diameter of oocyte was no differences among the treatment groups, but smaller than compared to in vivo grown oocyte. Through the entire culture period, secretions of oestradiol and progesterone were significantly less in control group than in HMG and FSH treatment groups. These results suggest that gonadotrophins playa key role in in vitro culture of mouse preantral follicles. Especially, addition of FSH and LH should be more effective than FSH alone.
본 연구는 생쥐 preantral follicle 의 체외성장 및 성숙에 있어서 gonadotrophins 인 FSH 와 LH 의 효과를 조사하기 위하여 실시하였으며, 그 결과는 다음과 같다. 1. FSH 첨가군들은 대조군에 비하여 유의하게 높은 생존율과 성숙율을 나타냈으며, 100$m\ell$D/$m\ell$ 의 FSH 농도가 preantral follicle 의 체외배양에 적정한 농도인 것으로 나타났다. 2. HMG 첨가군은 FSH 첨가군보다, 통계적 유의차는 인정되지 않았지만, 높은 생존율과 성숙율을 나타냈다. 3. FSH 와 LH 의 첨가비율이 100$m\ell$U/$m\ell$ 대 10$m\ell$D/$m\ell$(10:1) 에서 가장 높은 생존율과 성숙율을 나타냈다. 4. FSH 혹은 HMG 첨가시, 정상적인 oestradiol 과 progesterone 분비양상을 나타냈으며, HMG 첨가군에서 유의하게 높은 농도의 oestradiol 과 progesterone 을 분비하였다. 이상의 결과를 종합해 볼 때, gonadotrophins 은 preantral follicle 의 체외성장 및 성숙뿐만 아니라 steroidogenesis 에서 중요한 역할을 수행한다는 것을 확인할 수 있었다.
