概括
像上腺皮质激素 (ACTH) 这样的垂体激素可以直接到达大脑. 在羊群中增加ACTH.
科学领域:
- 神经内分泌学神经内分泌学
- 生理学 生理学 生理学
背景情况:
- 垂体激素直接运输到大脑是一个有争议的话题.
- 了解这种途径对于大脑功能和疾病研究至关重要.
研究的目的:
- 为了研究下垂体激素直接输送到大脑的假设.
- 测量大脑静脉血液中的 adrenocorticotropic 激素 (ACTH) 度.
主要方法:
- 在醒着的绵羊中,同时从动脉,斜鼻腔和静脉抽取血液样本.
- 电气诱导发作以刺激ACTH分泌.
- 在发作后精确间隔进行血ACTH度分析.
主要成果:
- 在发作后,斜侧鼻ACTH水平经常超过大脑动脉和关节水平.
- 这表明,来自垂体的ACTH进入大脑的毛细血管床,并通过 Sagittal sinus 出口.
- 在一只经过瘤切除的绵羊中,发作后升高的松鼻ACTH表明大脑衍生的ACTH释放.
结论:
- 有证据支持通过脑毛细管向大脑直接输送垂体ACTH.
- 大脑本身也可能释放ACTH或类似ACTH的物质.
相关概念视频
Hypothalamic-Pituitary Axis
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor.
Regulation of Hormone Secretion
Regulation of hormone secretion is a finely tuned orchestration driven by various types of stimuli, encompassing neural, humoral, and hormonal signals. Environmental cues instigate neural stimuli, where action potentials traverse nerve fibers to reach their designated targets. An illustrative scenario is the body's response to stress, wherein the sympathetic nervous system releases epinephrine from the adrenal glands, inducing the well-known 'fight or flight' reaction.
Humoral stimuli,...
Humoral stimuli,...
The Pituitary Gland
The pituitary is a small endocrine organ in the sphenoid bone under the hypothalamus. Primarily, the pituitary in adults has two distinct anatomical and functional regions— the anterior and posterior lobes. During human fetal development, a third pituitary gland region called the pars intermedia atrophies and disappears. However, some of its cells migrate and exist adjacent to the anterior pituitary in adults.
Hormones of the Pituitary Gland
The small, pea-sized pituitary gland is located at the base of the brain. It is crucial in regulating various bodily functions, from growth to reproduction. The gland is divided into the anterior lobe and the posterior lobe. The secretory cell clusters in the pars distalis of the anterior pituitary lobe are controlled by hypothalamic regulators and synthesize six primary hormones.
The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by...
The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by...
Hormones of the Adrenal Glands
Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla.
The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone...
The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone...
Cushing Syndrome II: Pathophysiology
Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the...


