Chiasson R B, Carr B L
Poult Sci. 1985 Jun;64(6):1205-9. doi: 10.3382/ps.0641205.
Pituitary cyclic adenosine monophosphate-dependent protein kinase (cAMP-PK) activity ratios of castrated cockerels on a short photoperiod are highest 2 weeks after testosterone removal in castrated birds and remain high through a 3rd week. Castrated cockerels on long photoperiods have a decline in cAMP-PK activity ratios after an elevation at 1 week following testosterone removal. This is interpreted to mean that the pituitaries of cockerels on short photoperiods are sensitive to testosterone inhibition but that this sensitivity disappears in long photoperiod-stimulated birds. Long daylengths also appear to enhance thyroid activity in castrated cockerels, although thyroid cAMP-PK activity ratios increase in the thyroid of all cockerels following the removal of testosterone (castration). These results suggest that testosterone has an inhibitory effect on both the pituitary and thyroid glands.
短光照周期下阉割公鸡的垂体环磷酸腺苷依赖性蛋白激酶（cAMP-PK）活性比在去除睾丸激素后的2周内最高，且在第3周仍保持较高水平。长光照周期下的阉割公鸡在去除睾丸激素1周后活性升高，随后cAMP-PK活性比下降。这被解释为短光照周期下公鸡的垂体对睾丸激素抑制敏感，但在长光照周期刺激的鸡中这种敏感性消失。长日照似乎也会增强阉割公鸡的甲状腺活性，尽管所有公鸡在去除睾丸激素（阉割）后甲状腺cAMP-PK活性比都会增加。这些结果表明，睾丸激素对垂体和甲状腺均有抑制作用。
