The effect of hypothalamo-pituitary disconnection on the functional and morphologic development of the pituitary-adrenal axis in the fetal sheep in the last third of gestation.
The effect of hypothalamo-pituitary disconnection on the functional and morphologic development of the pituitary-adrenal axis in the fetal sheep in the last third of gestation.
复制标题
下丘脑-垂体断开对妊娠最后三分之一胎羊垂体-肾上腺轴功能和形态发育的影响。
DOI：
10.1159/000125883
复制
发表时间：
1991
影响因子：
4.1
通讯作者：
Roslyn A. Perry
中科院分区：
文献类型：
--
作者：
G. Antolovich;I. McMillen;Peter M. Robinson;Marian Silver;I. Young;Roslyn A. Perry
本文研究了下丘脑-垂体切断(HPD)对胎羊血浆基础ir-ACTH和皮质醇浓度成熟的影响，以及对妊娠末期垂体前叶促肾上腺皮质激素群体发育的影响。HPD后，胎儿血浆ir-ACTH浓度显著升高，并随着胎龄的增加继续升高。然而，尽管ir-ACTH浓度升高，但胎儿血浆皮质醇浓度并没有增加，分娩至少比正常足月推迟了8天。此外，HPD导致远端促肾上腺皮质细胞成熟的显著中断。我们还检测了HPD后胎儿血浆ir-ACTH和皮质醇浓度对外源性CRF的影响。HPD组胎儿血浆ir-ACTH水平在CRF给药后显著升高，与假手术组胎儿相似。相反，与假手术的胎儿相比，HPD胎儿的血浆皮质醇反应较少。本研究结果表明，在妊娠的最后1/3，胎儿下丘脑不能维持ir-ACTH的分泌，在此期间，ir-ACTH的分泌受到下丘脑的强直抑制。脑下丘脑与下丘脑的分离扰乱了脑下丘脑-肾上腺轴的成熟，从而证明了下丘脑-脑垂体轴在正常成熟级联反应中的基本重要性，最终导致该物种出生。
We have investigated the effect of hypothalamo-pituitary disconnection (HPD) on the maturation of basal ir-ACTH and cortisol concentrations in fetal sheep plasma, and on the development of the anterior pituitary corticotroph population in the last third of gestation. After HPD, fetal plasma ir-ACTH concentrations were significantly elevated, and continued to rise with increasing gestational age. However, despite elevated ir-ACTH concentrations, there was no increase in fetal plasma cortisol concentrations, and parturition was delayed for at least 8 days beyond normal term. Furthermore, HPD resulted in a significant disruption of the maturation of the pars distalis corticotrophs. We also examined the change in fetal plasma concentrations of ir-ACTH and cortisol to exogenous CRF after HPD. There was a significant increase in plasma ir-ACTH in response to CRF administration in the HPD fetuses, which was qualitatively similar to that observed in sham-operated fetuses. In contrast, the plasma cortisol response was less in HPD fetuses when compared to that in sham-operated fetuses. The results of this study demonstrate that ir-ACTH secretion is not maintained by the fetal hypothalamus in the last third of gestation, and that ir-ACTH secretion is tonically inhibited by the hypothalamus during this time. The disconnection of the pituitary from the hypothalamus disrupts the maturation of the pituitary-adrenal axis, thus demonstrating the fundamental importance of the hypothalamo-pituitary axis in the normal maturational cascade which culminates in birth in this species.