Adrenal Medulla: I (Catecholamine Biosynthesis and Degradation)

2012 ◽  
pp. 76-77
Keyword(s):  
Adrenal Medulla ◽  
Catecholamine Biosynthesis

Regulation of nonclassical renin-angiotensin system receptor gene expression in the adrenal medulla by acute and repeated immobilization stress

2015 ◽  
Vol 308 (6) ◽  
pp. R517-R529 ◽  
Author(s):  
Regina Nostramo ◽  
Lidia Serova ◽  
Marcela Laukova ◽  
Andrej Tillinger ◽  
Chandana Peddu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adrenal Medulla ◽  
Immobilization Stress ◽  
Receptor Gene ◽  
Renin Angiotensin System ◽  
Mrna Levels ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Catecholamine Biosynthesis ◽  
Receptor Mrna

The involvement of the nonclassical renin-angiotensin system (RAS) in the adrenomedullary response to stress is unclear. Therefore, we examined basal and immobilization stress (IMO)-triggered changes in gene expression of the classical and nonclassical RAS receptors in the rat adrenal medulla, specifically the angiotensin II type 2 (AT2) and type 4 (AT4) receptors, (pro)renin receptor [(P)RR], and Mas receptor (MasR). All RAS receptors were identified, with AT2 receptor mRNA levels being the most abundant, followed by the (P)RR, AT1A receptor, AT4 receptor, and MasR. Following a single IMO, AT2 and AT4 receptor mRNA levels decreased by 90 and 50%, respectively. Their mRNA levels were also transiently decreased by repeated IMO. MasR mRNA levels displayed a 75% transient decrease as well. Conversely, (P)RR mRNA levels were increased by 50% following single or repeated IMO. Because of its abundance, the function of the (P)RR was explored in PC-12 cells. Prorenin activation of the (P)RR increased phosphorylation of extracellular signal-regulated kinase 1/2 and tyrosine hydroxylase at Ser31, likely increasing its enzymatic activity and catecholamine biosynthesis. Together, the broad and dynamic changes in gene expression of the nonclassical RAS receptors implicate their role in the intricate response of the adrenomedullary catecholaminergic system to stress.

Overpressure blast-wave induced brain injury elevates oxidative stress in the hypothalamus and catecholamine biosynthesis in the rat adrenal medulla

2013 ◽  
Vol 544 ◽  
pp. 62-67 ◽  
Author(s):  
Nihal Tümer ◽  
Stanislav Svetlov ◽  
Melissa Whidden ◽  
Nataliya Kirichenko ◽  
Victor Prima ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Brain Injury ◽  
Blast Wave ◽  
Adrenal Medulla ◽  
Catecholamine Biosynthesis ◽  
Wave Induced

scholarly journals Blast brain injury elevates catecholamine biosynthesis in the rat adrenal medulla

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Nihal Tümer ◽  
Stanislav Svetlov ◽  
Nataliya Kirichenko ◽  
Melissa Whidden ◽  
Benedek Erdos ◽  
...  
Keyword(s):  
Brain Injury ◽  
Adrenal Medulla ◽  
Catecholamine Biosynthesis

scholarly journals Bradykinin B2 Receptor in the Adrenal Medulla of Male Rats and Mice: Glucocorticoid-Dependent Increase With Immobilization Stress

Endocrinology ◽  
2013 ◽  
Vol 154 (10) ◽  
pp. 3729-3738 ◽  
Author(s):  
Regina Nostramo ◽  
Andrej Tillinger ◽  
Lidia Serova ◽  
Richard Kvetnansky ◽  
Esther L. Sabban
Keyword(s):  
Gene Expression ◽  
Adrenal Medulla ◽  
Immobilization Stress ◽  
Plasma Corticosterone ◽  
Male Rats ◽  
Mrna Levels ◽  
Stress Exposure ◽  
Bradykinin B2 Receptor ◽  
Catecholamine Biosynthesis ◽  
Catecholaminergic System

Bradykinin, acting via the bradykinin B2 receptor (B2R), is a potent stimulator of adrenomedullary catecholamine biosynthesis and release and likely plays an important role in the adrenomedullary stress response. However, the effects of stress on the expression of this receptor in the adrenal medulla are currently unclear. Here, we examined the changes in adrenomedullary B2R gene expression in male rats in response to single (1 time) and repeated (6 times) exposure to 2 hours immobilization stress (IMO). Immediately after 1 or 6 times IMO, B2R mRNA levels were increased by 9-fold and 7-fold, respectively, and returned to unstressed control levels 3 hours later. This large, but transient, increase in mRNA elicited a doubling of protein levels 3 hours after the stress exposure. Next, the role of the hypothalamic-pituitary-adrenocortical axis in the stress-induced upregulation of B2R gene expression was examined. Treatment with endogenous (corticosterone) and synthetic (dexamethasone) glucocorticoids dose-dependently increased B2R mRNA levels in adrenomedullary-derived PC12 cells. Furthermore, cortisol supplementation at levels mimicking stress exposure elevated B2R mRNA levels in the adrenal medulla of hypophysectomized rats. In response to 1 exposure to IMO, the stress-triggered rise in plasma corticosterone and adrenomedullary B2R mRNA levels was attenuated in CRH-knockout mice and absent in pharmacologically adrenalectomized rats, indicating a requirement for glucocorticoids in the upregulation of B2R gene expression with stress. Overall, the increase in B2R gene expression in response to the stress-triggered rise in glucocorticoids likely enhances catecholamine biosynthesis and release and may serve as an adaptive response of the adrenomedullary catecholaminergic system to stress.

Differences In Utero in Activities of Catecholamine Biosynthetic Enzymes in Adrenals of Spontaneously Hypertensive Rats

1981 ◽  
Vol 61 (s7) ◽  
pp. 227s-230s ◽  
Author(s):  
G. Teitelman ◽  
R. A. Ross ◽  
T. H. Joh ◽  
D. J. Reis
Keyword(s):  
Adrenal Medulla ◽  
Spontaneously Hypertensive Rats ◽  
Sympathetic Ganglia ◽  
Biosynthetic Enzymes ◽  
Sprague Dawley ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Catecholamine Biosynthesis ◽  
Sd Rats ◽  
Wistar Kyoto

1. We sought to determine if catecholamine biosynthetic enzymes of spontaneously hypertensive rats (SHR) differed from those of normotensive Wistar—Kyoto (WKY) and Sprague—Dawley (SD) control rats before birth. 2. By immunocytochemical and biochemical methods we compared strains for the time of appearance and maturation of the enzymes tyrosine hydroylase (TH), dopamine-β-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) in sympathetic ganglia and adrenals. 3. The time of appearance of enzymes was identical in all three strains: TH and DBH first appeared in sympathetic ganglia on embryonic day 11 (E11) and in adrenal medulla on E16. PNMT, restricted to adrenal medulla, appeared later on E18. 4. The activity of adrenal TH prenatally on E18 and E21 and at day of birth (P1) in SHR was approximately two fold that in WKY or SD rats. In contrast PNMT was lower in SHR but only on E18. 5. Thus, although the timing of the first expression of adrenergic phenotypes is similar in SHR and normotensive controls, the differences in TH activity in adrenals suggest an enhanced biosynthetic capacity for catecholamines in this strain before birth. 6. We conclude that SHR differ from normotensive rats from the first expression of some of the genes controlling catecholamine biosynthesis.

scholarly journals Traumatic Brain Injury elevates catecholamine biosynthesis in the rat adrenal medulla

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Nihal Tumer ◽  
Benedek Erdos ◽  
Melissa A. Whidden ◽  
Robert P. Yezierski ◽  
Charles J. Vierck ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Adrenal Medulla ◽  
Catecholamine Biosynthesis

scholarly journals Intricacies of the Molecular Machinery of Catecholamine Biosynthesis and Secretion by Chromaffin Cells of the Normal Adrenal Medulla and in Pheochromocytoma and Paraganglioma

Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1121 ◽  
Author(s):  
Berends ◽  
Eisenhofer ◽  
Fishbein ◽  
Horst-Schrivers ◽  
Kema ◽  
...  
Keyword(s):  
Adrenal Medulla ◽  
Chromaffin Cells ◽  
Chromaffin Cell ◽  
Histopathological Examination ◽  
Unmet Need ◽  
Sympathetic Ganglia ◽  
Prognostic Biomarkers ◽  
Adrenal Chromaffin Cell ◽  
Catecholamine Biosynthesis ◽  
Molecular Machinery

The adrenal medulla is composed predominantly of chromaffin cells producing and secreting the catecholamines dopamine, norepinephrine, and epinephrine. Catecholamine biosynthesis and secretion is a complex and tightly controlled physiologic process. The pathways involved have been extensively studied, and various elements of the underlying molecular machinery have been identified. In this review, we provide a detailed description of the route from stimulus to secretion of catecholamines by the normal adrenal chromaffin cell compared to chromaffin tumor cells in pheochromocytomas. Pheochromocytomas are adrenomedullary tumors that are characterized by uncontrolled synthesis and secretion of catecholamines. This uncontrolled secretion can be partly explained by perturbations of the molecular catecholamine secretory machinery in pheochromocytoma cells. Chromaffin cell tumors also include sympathetic paragangliomas originating in sympathetic ganglia. Pheochromocytomas and paragangliomas are usually locally confined tumors, but about 15% do metastasize to distant locations. Histopathological examination currently poorly predicts future biologic behavior, thus long term postoperative follow-up is required. Therefore, there is an unmet need for prognostic biomarkers. Clearer understanding of the cellular mechanisms involved in the secretory characteristics of pheochromocytomas and sympathetic paragangliomas may offer one approach for the discovery of novel prognostic biomarkers for improved therapeutic targeting and monitoring of treatment or disease progression.

scholarly journals The Abnormalities of Adrenomedullary Hormonal System in Genetic Hypertension: Their Contribution to Altered Regulation of Blood Pressure

2021 ◽  
pp. 307-326
Author(s):  
A Vavřínová
Keyword(s):  
Blood Pressure ◽  
Adrenal Medulla ◽  
Chromaffin Cells ◽  
Experimental Models ◽  
Spontaneously Hypertensive ◽  
Catecholamine Biosynthesis ◽  
Expression Of Genes ◽  
Hormonal System ◽  
Altered Regulation

It is widely accepted that sympathetic nervous system plays a crucial role in the development of hypertension. On the other hand, the role of adrenal medulla (the adrenomedullary component of the sympathoadrenal system) in the development and maintenance of high blood pressure in man as well as in experimental models of hypertension is still controversial. Spontaneously hypertensive rats (SHR) are the most widely used animal model of human essential hypertension characterized by sympathetic hyperactivity. However, the persistence of moderately elevated blood pressure in SHR subjected to sympathectomy neonatally as well as the resistance of adult SHR to the treatment by sympatholytic drugs suggests that other factors (including enhanced activity of the adrenomedullary hormonal system) are involved in the pathogenesis of hypertension of SHR. This review describes abnormalities in adrenomedullary hormonal system of SHR rats starting with the hyperactivity of brain centers regulating sympathetic outflow, through the exaggerated activation of sympathoadrenal preganglionic neurons, to the local changes in chromaffin cells of adrenal medulla. All the above alterations might contribute to the enhanced release of epinephrine and/or norepinephrine from adrenal medulla. Special attention is paid to the alterations in the expression of genes involved in catecholamine biosynthesis, storage, release, reuptake, degradation and adrenergic receptors in chromaffin cells of SHR. The contribution of the adrenomedullary hormonal system to the development and maintenance of hypertension as well as its importance during stressful conditions is also discussed.

Fine Structure of Carotid Body: Normal and Anoxic Cats

1967 ◽  
Vol 25 ◽  
pp. 150-151
Author(s):  
Fadhil Al-Lami ◽  
R.G. Murray
Keyword(s):  
Fine Structure ◽  
Adrenal Medulla ◽  
Carotid Body ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Glomus Cells ◽  
Sustentacular Cells ◽  
Carotid Bodies

Although the fine structure of the carotid body has been described in several recent reports, uncertainties remain, and the morphological effects of anoxia on the carotid body cells of the cat have never been reported. We have, therefore, studied the fine structure of the carotid body both in normal and severely anoxic cats, and to test the specificity of the effects, have compared them with the effects on adrenal medulla, kidney, and liver of the same animals. Carotid bodies of 50 normal and 15 severely anoxic cats (9% oxygen in nitrogen) were studied. Glutaraldehyde followed by OsO4 fixations, Epon 812 embedding, and uranyl acetate and lead citrate staining, were the technics employed.We have called the two types of glomus cells enclosed and enclosing cells. They correspond to those previously designated as chemoreceptor and sustentacular cells respectively (1). The enclosed cells forming the vast majority, are irregular in shape with many processes and occasional peripheral densities (Fig. 1).

Immunogold labeling of the calcium binding protein synexin in isolated adrenal chromaffin granules and chromaffin cells

1990 ◽  
Vol 48 (3) ◽  
pp. 952-953
Author(s):  
Gemma A.J. Kuijpers ◽  
Harvey B. Pollard
Keyword(s):  
Adrenal Medulla ◽  
Calcium Binding ◽  
Chromaffin Cells ◽  
Cell Activation ◽  
Structural Information ◽  
Dependent Manner ◽  
Chromaffin Granules ◽  
Immuno Electron Microscopy ◽  
Ultrathin Sections ◽  
Adrenal Chromaffin

Exocytotic fusion of granules in the adrenal medulla chromaffin cell is triggered by a rise in the concentration of cytosolic Ca2+ upon cell activation. The protein synexin, annexin VII, was originally found in the adrenal medulla and has been shown to cause aggregation and to support fusion of chromaffin granules in a Ca2+-dependent manner. We have previously suggested that synexin may there fore play a role in the exocytotic fusion process. In order to obtain more structural information on synexin, we performed immuno-electron microscopy on frozen ultrathin sections of both isolated chromaffin granules and chromaffin cells.Chromaffin granules were isolated from bovine adrenal medulla, and synexin was isolated from bovine lung. Granules were incubated in the presence or absence of synexin (24 μg per mg granule protein) and Ca2+ (1 mM), which induces maximal granule aggregation, in 0.3M sucrose-40m MMES buffer(pH 6.0). Granules were pelleted, washed twice in buffer without synexin and fixed with 2% glutaraldehyde- 2% para formaldehyde in 0.1 M phosphate buffer (GA/PFA) for 30 min. Chromaffin cells were isolated and cultured for 3-5 days, and washed and incubated in Krebs solution with or without 20 uM nicotine. Cells were fixed 90 sec after on set of stimulation with GA/PFA for 30 min. Fixed granule or cell pellets were washed, infiltrated with 2.3 M sucrose in PBS, mounted and frozen in liquid N2.

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