Drugs Affecting Autonomic Ganglia (Including the Adrenal Medulla)
Kenneth J. Broadley in Autonomic Pharmacology, 2017
Adrenal medullary chromaffin cells have the same embryonic origins as do ganglion cells, being formed from cells of the thoracic portion of the neural crest. These cells migrate to prevertebral regions to form the adrenal medullae together with the cells that become sympathetic ganglion cells. The mature adrenal medulla contains two types of chromaffin cells, namely adrenaline-containing (A-cells) and noradrenaline-containing (N-cells). At birth the cells are primarily of the N-type. They become A-type cells after birth due to the influence of the surrounding adrenal cortex mediated via the vasculature. The medulla is supplied directly by arteries from the capsule of the gland and by cortical veins which drain into the peripheral radicles of the central vein. The A-cells are arranged alongside these routes, which have high concentrations of adrenocortical hormones. These cortical steroids favour the development of adrenaline-containing cells because they induce the enzyme phenylethanolamine-N-methyltransferase (PNMT) that converts noradrenaline to adrenaline (see Chapter 2).
Adrenal Tumors
Dongyou Liu in Tumors and Cancers, 2017
The adrenal medulla is ellipsoid in shape, is gray-tan in color, and makes up <10% of gland volume (1% in neonates). Derived from neural crest and mostly found within the head of the gland, the adrenal medulla is composed of neural crest cells (also called chromaffin cells, pheochromocytes, or medullary cells, which are large polygonal cells arranged in small nests and cords separated by prominent vasculature, with poorly outlined borders and abundant granular and basophilic cytoplasm) and sustentacular cells (spindle-shaped supporting cells at the periphery of nests of chromaffin cells). The chromaffin cells are the key supplier of catecholamines, including epinephrine (adrenaline, 80%) and norepinephrine (noradrenaline, 20%), for regulation of blood pressure and heart rate.
Hereditary Pheochromocytoma and Paraganglioma Syndrome
Dongyou Liu in Handbook of Tumor Syndromes, 2020
Pheochromocytoma and paraganglioma (PPGL) are rare tumors of the paraganglia, which are formed by the aggregation of the cell nuclei of the autonomic nervous system (including sympathetic and parasympathetic nerves), symmetrically distributed along the paravertebral axis from the base of the skull and neck to the pelvis, with the largest found in the adrenal medulla. Specifically, pheochromocytoma (also known as adrenal chromaffin cell tumor) is catecholamine-secreting paraganglioma confined to the adrenal medulla. Sympathetic paraganglioma located along the paravertebral axis (and not in the adrenal gland) is known as extra-adrenal sympathetic paraganglioma. Since most PPGL (especially those affecting the adrenal glands) secrete excessive amounts of catecholamines that predispose to elevated blood pressure, palpitations, sweats, anxiety, and gastrointestinal disease, they are also known as neuroendocrine tumors [1].
The carotid body and associated tumors: updated review with clinical/surgical significance
Published in British Journal of Neurosurgery, 2019
Nasir Butt, Woong Kee Baek, Stefan Lachkar, Joe Iwanaga, Asma Mian, Christa Blaak, Sameer Shah, Christoph Griessenauer, R. Shane Tubbs, Marios Loukas
The carotid bodies are the largest paraganglia of the head and neck. ‘Paraganglia’ denotes extra-suprarenal gland aggregations of chromaffin tissue. Chromaffin cells are embryologically derived from neuro-ectoderm and are innervated by pre-ganglionic sympathetic nerve fibers, and secrete catecholamines.9 The term ‘paraganglion system’ was coined to denote these extra-suprarenal gland sites. This system is vital for fetal development until the formation of the suprarenal medulla, which eventually takes over the catecholamine production.10 After birth, most of these cells degenerate except those populated along the autonomic nervous system and in the walls of some organs. Paraganglia typically consist of two types of cells based on their histological characteristics: type I are granule containing cells and type II are satellite cells. The granules of type I cells are filled with catecholamines and tryptophan-rich proteins. The main anatomical sites of paraganglia along the autonomic nervous system are the carotid, aortic-pulmonary, para-aortic, and coccygeal bodies.
Strong stimulation triggers full fusion exocytosis and very slow endocytosis of the small dense core granules in carotid glomus cells
Published in Journal of Neurogenetics, 2018
Amy Tse, Andy K. Lee, Noriko Takahashi, Alex Gong, Haruo Kasai, Frederick W. Tse
We found that even at 100 s after the UV flash, glomus cells retrieved only ∼40% of the vesicular membrane. In contrast, our previous study in corticotropes has shown that Cm returned to baseline within 10 s after the UV flash (Lee & Tse, 2001). The very slow classical endocytosis in glomus cells was correlated to the low densities of dynamin I, II and clathrin. It is generally accepted that the classical endocytosis in secretory cells is clathrin-dependent (Wu et al., 2014). In bovine chromaffin cells, pharmacological inhibitions of dynamin-II or clathrin were found to reduce slow endocytosis, and rapid endocytosis could be inhibited by the disruption of dynamin-I (Artalejo, Elhamdani, & Palfrey, 2002; Elhamdani, Azizi, Solomaha, Palfrey, & Artalejo, 2006b; Tsai et al.,2009). Since the cytoplasmic densities of dynamin I, II and clathrin in glomus cells were less than half of those in chromaffin cells (Figure 5(B)), it is probably that fewer endocytic machinery contribute to the slower classical endocytosis in glomus cells. The slow rate of endocytosis in glomus cells is probably related to their normally low secretory output for the paracrine/autocrine regulation of the carotid body functions. Thus, it is not essential for the glomus SDCGs to be rapidly replenished with transmitters. In contrast, chromaffin cells release large amount of hormones into the circulation during the ‘fight or flight response’ and a rapid replenishment of chromaffin granules would be crucial.
The neurosciences at the Max Planck Institute for Biophysical Chemistry in Göttingen
Published in Journal of the History of the Neurosciences, 2023
Heinz Wässle, Sascha Topp
Whittaker and his colleagues further elicited that, in the presynaptic plasma membrane, a high-affinity uptake system for choline exists that is blocked by snake poisons such as Alpha-Bungarotoxin. Another model system for the release of neurotransmitter substances established by Whittaker and his colleagues was the chromaffin cell from the adrenal medulla, whose vesicles, which are referred to as granules, are filled with catecholamines. The chromaffin cells are innervated by sympathetic nerve axons and release adrenaline or norepinephrine when excited. Elizabeth Fenwick (b. 1952), an Australian postdoctoral student, had developed a technique with which she was able to dissociate and enrich chromaffin cells (Fenwick et al. 1978). Whittaker and his coworkers then used these chromaffin cells to study the fusion of the granuli as a model for exocytosis (transporting substance out of the cell). They demonstrated that fusion is preceded by a multiple-stage process in which a network of proteins and specific detection mechanisms play an important role. As was to be shown later by Erwin Neher and his colleagues at the same institute, chromaffin cells were used successfully in patch clamp research (Fenwick, Marty, and Neher 1982).
Related Knowledge Centers
- Adrenal Medulla
- Adrenaline
- Neuroendocrine Cell
- Splanchnic Nerves
- Sympathetic Nervous System
- Catecholamine
- Circulatory System
- Norepinephrine
- Adrenal Gland
- Sympathetic Ganglia