Functional development of the hypothalamo-hypophyseal-adrenal cortex axis in the chick embryo, Gallus domesticus.
Functional development of the hypothalamo-hypophyseal-adrenal cortex axis in the chick embryo, Gallus domesticus.
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鸡胚鸡内下丘脑-垂体-肾上腺皮质轴的功能发育。
DOI：
10.1002/jez.1401850302
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
B. Frye
中科院分区：
文献类型：
--
作者：
P. Wise;B. Frye
基础血浆皮质酮水平逐渐增加，在孵化的后半期，孵化时左右达到高峰。应激导致16天或更长时间的胚胎中皮质酮高于基础水平的非常显著的升高，但在更年轻的胚胎中则不然。新孵化的小鸡没有反应的压力，但一个典型的压力反应是明显的孵化后一周。促肾上腺皮质激素（100 mU）引起血浆皮质酮在14天的胚胎和新孵化的小鸡，表明肾上腺能够响应垂体刺激在这些时候，当应激反应不发生显着上升。
断头16天的胚胎有显着较低的基础水平的皮质酮比正常的，并没有表现出皮质酮在应激反应上升。皮质酮的基础水平不受断头的14天胚胎。在孵化的第9天，将10天的胚胎垂体移植到绒毛尿囊膜上，在第16天，断头胚胎恢复了正常的基础激素水平，但没有恢复对压力的反应能力。
本研究表明，雏鸡下丘脑-垂体-肾上腺轴在孵化前是有功能的。肾上腺表现出显着的自主功能能力之前的第14天，和垂体成为重要的在保持激素的静息水平和应激反应之间的第14和16天的孵化。下丘脑似乎并不控制皮质酮的正常静息水平，但对应激反应至关重要。
Basal plasma levels of corticosterone increased gradually during the second half of incubation, reaching a peak around the time of hatching. Stress resulted in a very significant elevation of corticosterone above the basal level in embryos 16 days or older, but not in younger embryos. Newly hatched chicks did not respond to stress, but a typical stress response was evident one week after hatching. Adrenocorticotropin (100 mU) elicited a significant rise in plasma corticosterone in 14-day embryos and in newly hatched chicks, demonstrating that the adrenal is capable of responding to pituitary stimulation at these times when a stress response does not occur.
Decapitated 16-day embryos had significantly lower basal levels of corticosterone than normal, and showed no rise in corticosterone in response to stress. Basal levels of corticosterone were unaffected by decapitation of 14-day embryos. Grafting ten-day embryonic pituitaries to the chorioallantoic membrane on day 9 of incubation restored normal basal hormone levels on day 16 in decapitated embryos, but did not restore the ability to respond to stress.
This study demonstrates that the hypothalamo-hypophyseal-adrenal axis is functional before hatching in chicks. The adrenal exhibits significant autonomous functional capability prior to day 14, and the pituitary becomes important in maintaining both the resting level of hormone and the stress response between days 14 and 16 of incubation. The hypothalamus does not appear to control normal resting levels of corticosterone, but is essential for the stress response.