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Hormones of the Adrenal Gland
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The adrenal medulla contains two types of modified ganglion cells called chromaffin cells. These contain granules of either norepinephrine or epinephrine associated with soluble acidic proteins called chromogranin, lipids and ATP. Some 80% of the chromaffin cells have large and less dense granules containing epinephrine, and 20% have small and dense granules containing norepinephrine. The preganglionic sympathetic fibres that innervate the adrenal medulla are derived from T5–T9.
Adrenal Medulla
Published in Paul V. Malven, Mammalian Neuroendocrinology, 2019
In the discussion on biological actions of catecholamines, the induced breakdown of glycogen to yield glucose was one important action that could only be accomplished by adrenomedullary secretions. Therefore, low blood glucose (hypoglycemia) represents one of the most important provocative stimuli of such secretion. Chromaffin cells are directly stimulated by hypoglycemia that is perceived in the CNS and increases sympathetic outflow to the adrenal medulla. Another possible mechanism by which hypoglycemia may stimulate chromaffin cells is through increases in the secretion of the hormone glucagon from the pancreas. Hypoglycemia is known to stimulate glucagon release, and this hormone can directly stimulate norepinephrine and epinephrine release from chromaffin cells (Lewis, 1975).
Pheochromocytoma and Paraganglioma
Published in Giuseppe Mancia, Guido Grassi, Konstantinos P. Tsioufis, Anna F. Dominiczak, Enrico Agabiti Rosei, Manual of Hypertension of the European Society of Hypertension, 2019
Andrzej Januszewicz, Jacques W.M. Lenders, Graeme Eisenhofer, Aleksander Prejbisz
The terminology of chromaffin cell tumours is sometimes confusing when pheochromocytoma and paraganglioma are interchangeably used. The term pheochromocytoma should be reserved for chromaffin cell tumours of the adrenal gland, while the term paraganglioma should be used for extra-adrenal chromaffin cell tumours. This distinction is clinically relevant because these tumours not only differ in location but also in clinical presentation, genetic background and malignant potential.
Clinical presentation and diagnostic evaluation of pheochromocytoma: case series and literature review
Published in Clinical and Experimental Hypertension, 2023
Panagiota Anyfanti, Κonstantinos Mastrogiannis, Αntonios Lazaridis, Κonstantinos Tasios, Despoina Vasilakou, Αnastasia Kyriazidou, Fotios Aroutsidis, Olga Pavlidou, Εleni Papoutsopoulou, Athina Tiritidou, Vasileios Kotsis, Αreti Triantafyllou, Ιoannis Zarifis, Stella Douma, Εugenia Gkaliagkousi
Pheochromocytomas are neuroendocrine tumors producing catecholamines that derive from the chromaffin cells and develop within the adrenal medulla and autonomic nerve ganglia. Neoplasms that develop from chromaffin tissue outside the adrenal gland are called extra-adrenal pheochromocytomas or paragangliomas. The same term is used to describe tumors deriving from head or neck parasympathetic tissue, which, usually, don’t produce catecholamines. Almost 80–85% of pheochromocytomas develop within the adrenal gland medulla and only 10–15% derive from extra-adrenal tissue. The tumor is rare, with an estimated incidence of 2–8 cases for every million people and prevalence ranging from 0.2–0.6% of the general hypertensive population (1,2). Mean age of diagnosis is 40–50 years, although it can occur from childhood to late in adulthood (3,4). In around one-third (25–33%) of cases, pheochromocytoma occurs in the context of familial syndromes such as multiple endocrine neoplasia syndromes (MEN 2A, MEN 2B), type I neurofibromatosis, von Hippel-Lindau disease, Sturge-Webber syndrome and other paraganglioma syndromes. In these cases, the diagnosis is usually made at a younger age, typically before the 4th decade of life (5).
The neurosciences at the Max Planck Institute for Biophysical Chemistry in Göttingen
Published in Journal of the History of the Neurosciences, 2023
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).
Pheochromocytoma diagnosed during pregnancy: a case report
Published in Gynecological Endocrinology, 2020
Giulia Misasi, Federica Pancetti, Andrea Giannini, Tommaso Simoncini, Paolo Mannella
Pheochromocytoma is a rare catecholamine producing tumor arising from the chromaffin cells of the medullary region of the adrenal gland or sympathetic ganglia [1]. This tumor accounts for 0.2 to 0.4% of hypertensive disorders [2] and its prevalence during pregnancy is approximately 0.0002% [3]. If untreated, maternal and fetal mortality is approximately around 40–50% [4], rate that decreases to less than 5% for maternal mortality and less than 15% for fetal mortality once treated [5]. During pregnancy, pheochromocytoma might not have any specific signs and symptoms. In addition, distinctive symptoms, such as sweating attacks, palpitations and blood pressure crisis, are mild among pregnant women compared to non-pregnant ones [6]. A delayed diagnosis may put mother and child in serious risk.