Kasuga F, Takahashi M
Endocrinol Jpn. 1986 Feb;33(1):105-15. doi: 10.1507/endocrj1954.33.105.
The endocrine function of rat gonads with an experimentally reduced number of germ cells was examined to analyse the effect of germ cells on the surrounding somatic endocrine cells. Pregnant Wistar rats received a single i.v. injection of 10 mg/kg B.W. of Busulphan on day 15 of gestation to prevent fetal primordial germ cells from starting mitotic division. The gonadal growth and the number of germ cells in Busulphan-treated rats (B-rats) were severely arrested. Almost a normal testicular structure was formed in the males, while few follicular structures were formed in the females, suggesting that the presence of oocytes in the fetal ovary is a prerequisite to the formation of the follicle. The meiotic division of spermatogonia in B-rats, which started on day 20 as in controls, stopped before the completion of spermatogenesis, and germ cells disappeared by day 50. The remaining germ cells and the associated follicles in female B-rats also disappeared by day 60 after repeating irregular estrous cycles for approximately 1 month. Thereafter the ovary consisted of fibroblasts and morphologically interstitial-like cells. Vaginal opening occurred in B-rats on day 28-30, a-week earlier than in controls. Changes in serum GTH after ovariectomy and the estradiol treatment suggested the maturation of the negative feedback sensitivity to estradiol in this period, and besides, earlier estradiol production with less dependency on gonadotropin. The vaginal epithelium of B-rats was cornified continuously after day 60. The ovarian cells in this period did not luteinize either morphologically or functionally in response to an ovulatory dose of hCG. During the same period, the conversion rate from progesterone to estradiol in ovarian homogenates of B-rats was considerably higher than those of controls at any stage of the estrous cycle. High content of estradiol was detected in the testes of B-rats at any age. In male B-rats, both LH and FSH levels in serum were higher than controls. The serum testosterone concentration in B-rats was lower than the normal, while the testicular testosterone content was greater. In conclusion, with a decreased number of germ cells, the rat gonads of both sexes secrete estradiol very efficiently.
为分析生殖细胞对周围体细胞内分泌细胞的影响，对实验性生殖细胞数量减少的大鼠性腺的内分泌功能进行了研究。妊娠第15天，给怀孕的Wistar大鼠静脉注射10mg/kg体重的白消安，以阻止胎儿原始生殖细胞开始有丝分裂。白消安处理的大鼠（B组大鼠）的性腺生长和生殖细胞数量严重停滞。雄性大鼠形成了几乎正常的睾丸结构，而雌性大鼠形成的卵泡结构很少，这表明胎儿卵巢中卵母细胞的存在是卵泡形成的先决条件。B组大鼠精原细胞的减数分裂在第20天开始，与对照组一样，但在精子发生完成前停止，到第50天时生殖细胞消失。雌性B组大鼠中剩余的生殖细胞和相关卵泡在经历约1个月的不规则发情周期后，到第60天时也消失了。此后，卵巢由成纤维细胞和形态上类似间质的细胞组成。B组大鼠在第28 - 30天阴道开口，比对照组早一周。卵巢切除和雌二醇处理后血清促性腺激素（GTH）的变化表明，在此期间对雌二醇的负反馈敏感性成熟，此外，雌二醇产生更早，对促性腺激素的依赖性更小。B组大鼠的阴道上皮在第60天后持续角化。在此期间，给予排卵剂量的人绒毛膜促性腺激素（hCG）后，卵巢细胞在形态和功能上均未黄体化。同一时期，B组大鼠卵巢匀浆中孕酮向雌二醇的转化率在发情周期的任何阶段都明显高于对照组。在任何年龄的B组大鼠睾丸中都检测到高含量的雌二醇。在雄性B组大鼠中，血清中促黄体生成素（LH）和促卵泡生成素（FSH）水平均高于对照组。B组大鼠血清睾酮浓度低于正常水平，而睾丸睾酮含量更高。总之，随着生殖细胞数量减少，两性大鼠性腺都能非常有效地分泌雌二醇。
