Péczely P
Acta Biol Hung. 1985;36(1):45-70.
The role of the thyroid gland in modulating the gonad function depends on the functional state of the gonads. In sexually inactive (short-day's) male Japanese quails, thyroidectomy and thyroxine treatment prove ineffective. Thyroxine administered simultaneously with photo-gonadostimulation inhibits the maturation of the gonads: the testes decrease in weight, the metabolic clearance rate of testosterone accelerates, resulting in a decrease in the plasma level, and androsterone production increases. Photo-gonadostimulation of thyroidectomized quails shows down the growth of the testicles and decreases the plasma testosterone level. The latter change can be related to the inhibition of the secretion rate. Both thyroidectomy and thyroxine administration performed in mature male quail, cock, pigeon or Peking duck lower the testosterone plasma level. The loss of the testicular weight is more expressed in hyperthyroid than in normal quails, referring to the role of the increased thyroxine level in the seasonal (summer) gonadal involution. Thyroidectomy performed on sexually inactive (short-day's) female Japanese quails does not affect the ovarian structure, but 17 beta-oestradiol and testosterone plasma levels show a slight increase. Thyroxine administration is followed by a moderate increase in the size of the white follicles, and an increase of both the progesterone and the oestrogen concentrations. Photo-gonadostimulation of thyroidectomized quails causes an inhibition of the mechanism of ovulation without inhibiting the development of the yellow follicles. A similar phenomenon has been observed in mature quails and domestic fowls after thyroidectomy. In both cases, an unbalanced secretion of the sexual steroids occurs: the 17 beta-oestradiol plasma level declines, while the progesterone level increases. Simultaneous application of thyroxine and photo-gonadostimulation on female quails inhibits gonadal maturation: the growing of the yellow follicles slows down. In thyroxine-treated birds, the plasma level of all of the sexual steroids shows a considerable decrease, which can be attributed to a reduced secretion rate and increased metabolic clearance. In hatching turkeys, we failed to observe the increase of the T3 level described for other species, however, the T4 plasma concentration was increasing at the early period of hatching. The role of the thyroid hormones in the development of hatching has not been cleared up so far. Corticosterone administration shows a slight stimulating effect on the gonadal function of sexually inactive male and female Japanese quails.(ABSTRACT TRUNCATED AT 400 WORDS)
甲状腺调节性腺功能的作用取决于性腺的功能状态。在性不活跃（短日照）的雄性日本鹌鹑中，甲状腺切除和甲状腺素治疗均无效。与光刺激性腺成熟同时给予甲状腺素会抑制性腺成熟：睾丸重量减轻，睾酮的代谢清除率加快，导致血浆水平下降，雄甾酮生成增加。对甲状腺切除的鹌鹑进行光刺激性腺成熟会减缓睾丸生长并降低血浆睾酮水平。后一种变化可能与分泌率的抑制有关。在成熟雄性鹌鹑、公鸡、鸽子或北京鸭中进行甲状腺切除和给予甲状腺素都会降低血浆睾酮水平。甲状腺功能亢进的鹌鹑睾丸重量损失比正常鹌鹑更明显，这表明甲状腺素水平升高在季节性（夏季）性腺退化中的作用。对性不活跃（短日照）的雌性日本鹌鹑进行甲状腺切除不影响卵巢结构，但血浆17β - 雌二醇和睾酮水平略有升高。给予甲状腺素后，白色卵泡大小适度增加，孕酮和雌激素浓度均升高。对甲状腺切除的鹌鹑进行光刺激性腺成熟会抑制排卵机制，但不抑制黄色卵泡的发育。在成熟鹌鹑和家鸡甲状腺切除后也观察到了类似现象。在这两种情况下，性类固醇分泌失衡：血浆17β - 雌二醇水平下降，而孕酮水平升高。对雌性鹌鹑同时应用甲状腺素和光刺激性腺成熟会抑制性腺成熟：黄色卵泡生长减缓。在接受甲状腺素治疗的鸟类中，所有性类固醇的血浆水平均显著下降，这可归因于分泌率降低和代谢清除增加。在孵化中的火鸡中，我们未观察到其他物种所描述的T3水平升高，然而，血浆T4浓度在孵化早期升高。甲状腺激素在孵化过程中的作用目前尚未明确。给予皮质酮对性不活跃的雄性和雌性日本鹌鹑的性腺功能有轻微刺激作用。（摘要截于400字）
