High concentrations of catecholamines in human hypothalamic-hypophysial blood
R Paradisi1, G Frank, G Grossi
1Department of Obstetrics and Gynecology, S. Orsola Hospital, Bologna, Italy.
The Journal of Clinical Investigation
|June 1, 1989
Summary
Researchers collected suprapituitary blood in humans to study hypothalamic-hypophysial function. This blood is rich in catecholamines (CAs), suggesting a direct neurohormonal role in human pituitary regulation.
Area of Science:
- Neuroendocrinology
- Human Physiology
Background:
- The hypothalamic-hypophysial portal system is well-studied in animals but not humans.
- Understanding human portal blood composition is crucial for neuroendocrine research.
Purpose of the Study:
- To develop a method for collecting suprapituitary blood in humans.
- To analyze catecholamine (CA) concentrations in suprapituitary blood to infer hypothalamic activity.
Main Methods:
- Experimental procedure for collecting suprapituitary blood in humans.
- Measurement of norepinephrine (NE), dopamine (DA), and epinephrine (E) concentrations.
- Discriminant analysis of CA levels for group separation.
Main Results:
- Suprapituitary blood showed significantly higher concentrations of NE, DA, and E compared to peripheral blood.
- Distinct NE/DA and NE/E ratios were observed in suprapituitary blood, favoring DA and E.
- Discriminant analysis using DA and E achieved 100% separation between suprapituitary and peripheral blood.
Conclusions:
- Suprapituitary blood composition differs from peripheral blood, being notably rich in CAs.
- Data support a hypothalamic origin of these CAs, draining into the portal vasculature.
- CAs may function as neurohormones regulating human hypothalamic-hypophysial function.
Related Concept Videos
01:37Hypothalamic-Pituitary Axis
49.3K
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.
49.3K
01:27Adrenergic Neurons: Neurotransmission
5.4K
Postganglionic sympathetic fibers (except those supplying the sweat glands) releasing noradrenaline or norepinephrine are called noradrenergic or adrenergic neurons. Noradrenaline, dopamine, adrenaline, or epinephrine are collectively called "catecholamines" as they contain a catechol moiety and an amine side chain. The five stages of neurotransmitter release involve their synthesis, storage, release, reuptake and metabolism.
Synthesis: Catecholamine synthesis requires tyrosine, which...
Synthesis: Catecholamine synthesis requires tyrosine, which...
5.4K
01:16Sympathetic Activation
6.1K
The sympathetic division can influence tissues and organs by releasing norepinephrine at peripheral synapses and distributing epinephrine and norepinephrine through the bloodstream. In times of crisis or stress, sympathetic activation occurs, which is regulated by sympathetic centers in the hypothalamus. As a result, sympathetic activation prepares the body for physical exertion, rapid ATP production, and heightened alertness, allowing individuals to respond effectively to challenging or...
6.1K
01:31Hormones of the Adrenal Glands
6.0K
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...
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...
6.0K
01:17Hormonal Regulation of Blood Pressure
7.9K
Endocrinal or hormonal intervention in the cardiovascular system is predominantly exerted by the catecholamines - epinephrine and norepinephrine, as well as a slew of hormones that interact with renal function to modulate blood volume.
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction...
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction...
7.9K
01:19Cushing Syndrome II: Pathophysiology
56
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...
56