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Xu S, Shen X, Liu S, Yang J, Wang X. Efficacy and safety of norepinephrine versus phenylephrine for the management of maternal hypotension during cesarean delivery with spinal anesthesia: A systematic review and meta-analysis. Medicine (Baltimore) 2019; 98:e14331. [PMID: 30702617 PMCID: PMC6380847 DOI: 10.1097/md.0000000000014331] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Phenylephrine is the current "gold standard' vasopressor used to treat maternal hypotension in women undergoing cesarean delivery with spinal anesthesia. Since 2015, various studies have explored the use of norepinephrine to manage maternal hypotension. We conducted this systematic review and meta-analysis of available randomized controlled trials (RCTs) to compare the efficacy and safety of norepinephrine and phenylephrine for the prevention and treatment of maternal hypotension. METHODS A systematic literature search was conducted using electronic databases, including PubMed, MEDLINE, Embase (Embase.com), and the Cochrane CENTRAL register of controlled trials. Parturients underwent cesarean delivery with spinal anesthesia and received norepinephrine to prevent or treat hypotension were considered. Maternal outcomes, including incidences of hypotension, hypertension, bradycardia, intraoperative nausea and vomiting (IONV), maternal cardiac output (CO), and blood pressure (BP) control precision, as well as neonatal Apgar scores and umbilical cord blood analyses, were compared between groups. RESULTS Three RCTs in 4 reports published between 2015 and 2018 were finally identified with a total of 294 parturients. We found there was no difference in effectiveness between norepinephrine and phenylephrine for the treatment of maternal hypotension (odds ratio [OR] 0.64; 95% confidence interval [CI] 0.37-1.10, P = .11), and there was no difference in the occurrence of hypertension (OR 0.74; 95% CI 0.33-1.62, P = .45). Of note, compared to the phenylephrine group, parturients in the norepinephrine group were less likely to experience bradycardia (OR 0.29; 95% CI 0.12-0.68, P = .005) and IONV (OR 0.54; 95% CI, 0.29-0.99, P = .04). Further, we did not observe a difference between the two vasopressors in the incidence of neonatal Apgar scores < 7 at 1 and 5 minutes or in umbilical vein (UV) blood gas. However, evidence is insufficient to draw conclusions regarding the greater maternal CO and better BP control precision with the use of norepinephrine. CONCLUSION This systematic review and meta-analysis shows norepinephrine provides similar efficacy to manage maternal hypotension compared to phenylephrine; additionally, showing advantage regarding certain side effects like bradycardia and IONV reduction. Accordingly, norepinephrine is a promising alternative to phenylephrine. However, before routine clinical application, more studies are warranted.
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Affiliation(s)
- Shiqin Xu
- Department of Anesthesiology and Intensive Care Medicine, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University
| | - Xiaofeng Shen
- Department of Anesthesiology and Intensive Care Medicine, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University
| | - Shijiang Liu
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing
| | - Jianjun Yang
- Department of Anesthesiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xian Wang
- Department of Anesthesiology and Intensive Care Medicine, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University
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The Efficacy and Safety of Norepinephrine and Its Feasibility as a Replacement for Phenylephrine to Manage Maternal Hypotension during Elective Cesarean Delivery under Spinal Anesthesia. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1869189. [PMID: 30687737 PMCID: PMC6330831 DOI: 10.1155/2018/1869189] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/17/2018] [Accepted: 12/04/2018] [Indexed: 12/12/2022]
Abstract
Maternal hypotension commonly occurs during spinal anesthesia for cesarean delivery, with a decrease of systemic vascular resistance recognized as a significant contributor. Accordingly, counteracting this effect with a vasopressor that constricts arterial vessels is appropriate, and the pure α-adrenergic receptor agonist phenylephrine is the current gold standard for treatment. However, phenylephrine is associated with dose-dependent reflex bradycardia and decreased cardiac output, which can endanger the mother and fetus in certain circumstances. In recent years, the older, traditional vasopressor norepinephrine has attracted increasing attention owing to its mild β-adrenergic effects in addition to its α-adrenergic effects. We search available literature for papers directly related to norepinephrine application in spinal anesthesia for elective cesarean delivery. Nine reports were found for norepinephrine use either alone or compared to phenylephrine. Results show that norepinephrine efficacy in rescuing maternal hypotension is similar to that of phenylephrine without obvious maternal or neonatal adverse outcomes, and with a lower incidence of bradycardia and greater cardiac output. In addition, either computer-controlled closed loop feedback infusion or manually-controlled variable-rate infusion of norepinephrine provides more precise blood pressure management than equipotent phenylephrine infusion or norepinephrine bolus. Thus, based on the limited available literature, norepinephrine appears to be a promising alternative to phenylephrine; however, before routine application begins, more favorable high-quality studies are warranted.
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Müller MS, Vyssotski AL, Yamamoto M, Yoda K. Heart rate variability reveals that a decrease in parasympathetic (‘rest-and-digest’) activity dominates autonomic stress responses in a free-living seabird. Comp Biochem Physiol A Mol Integr Physiol 2017; 212:117-126. [DOI: 10.1016/j.cbpa.2017.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/13/2017] [Accepted: 07/19/2017] [Indexed: 10/19/2022]
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Performance of a closed-loop feedback computer-controlled infusion system for maintaining blood pressure during spinal anaesthesia for caesarean section: a randomized controlled comparison of norepinephrine versus phenylephrine. J Clin Monit Comput 2017; 31:617-623. [DOI: 10.1007/s10877-016-9883-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/25/2016] [Indexed: 10/21/2022]
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Shoemaker JK, Badrov MB, Al-Khazraji BK, Jackson DN. Neural Control of Vascular Function in Skeletal Muscle. Compr Physiol 2015; 6:303-29. [PMID: 26756634 DOI: 10.1002/cphy.c150004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The sympathetic nervous system represents a fundamental homeostatic system that exerts considerable control over blood pressure and the distribution of blood flow. This process has been referred to as neurovascular control. Overall, the concept of neurovascular control includes the following elements: efferent postganglionic sympathetic nerve activity, neurotransmitter release, and the end organ response. Each of these elements reflects multiple levels of control that, in turn, affect complex patterns of change in vascular contractile state. Primarily, this review discusses several of these control layers that combine to produce the integrative physiology of reflex vascular control observed in skeletal muscle. Beginning with three reflexes that provide somewhat dissimilar vascular patterns of response despite similar changes in efferent sympathetic nerve activity, namely, the baroreflex, chemoreflex, and muscle metaboreflex, the article discusses the anatomical and physiological bases of postganglionic sympathetic discharge patterns and recruitment, neurotransmitter release and management, and details of regional variations of receptor density and responses within the microvascular bed. Challenges are addressed regarding the fundamentals of measurement and how conclusions from one response or vascular segment should not be used as an indication of neurovascular control as a generalized physiological dogma. Whereas the bulk of the article focuses on the vasoconstrictor function of sympathetic neurovascular integration, attention is also given to the issues of sympathetic vasodilation as well as the impact of chronic changes in sympathetic activation and innervation on vascular health. © 2016 American Physiological Society.
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Affiliation(s)
- J K Shoemaker
- School of Kinesiology, Western University, London, Ontario, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - M B Badrov
- School of Kinesiology, Western University, London, Ontario, Canada
| | - B K Al-Khazraji
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - D N Jackson
- Department of Medical Biophysics, Western University, London, Ontario, Canada
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Gray JM, Chaouloff F, Hill MN. To stress or not to stress: a question of models. ACTA ACUST UNITED AC 2015; 70:8.33.1-8.33.22. [PMID: 25559007 DOI: 10.1002/0471142301.ns0833s70] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Stress research is a rapidly evolving field that encompasses numerous disciplines ranging from neuroscience to metabolism. With many new researchers migrating into the field, navigating the hows and whys of specific research questions can sometimes be enigmatic given the availability of so many models in the stress field. Additionally, as with every field, there are many seemingly minor experimental details that can have dramatic influences on data interpretation, although many of these are unknown to those not familiar with the field. The aim of this overview is to provide some suggestions and points to guide researchers moving into the stress field and highlight relevant methodological points that they should consider when choosing a model for stress and deciding how to structure a study. We briefly provide a primer on the basics of endpoint measurements in the stress field, factors to consider when choosing a model for acute stress, the difference between repeated and chronic stress, and importantly, influencing variables that modulate endpoints of analysis in stress work.
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Affiliation(s)
- J Megan Gray
- Hotchkiss Brain Institute, Mathison Centre for Mental Health Research, University of Calgary, Alberta, Canada
| | - Francis Chaouloff
- Endocannabinoids and NeuroAdaptation, Neurocentre INSERM U862, University Bordeaux 2, Bordeaux, France
| | - Matthew N Hill
- Hotchkiss Brain Institute, Mathison Centre for Mental Health Research, University of Calgary, Alberta, Canada
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Abstract
By inducing BK (bradykinin)-stimulated adrenomedullary catecholamine release, bolus injection of the β-fragment of activated plasma coagulation Factor XII (β-FXIIa) transiently elevates BP (blood pressure) and HR (heart rate) of anaesthetized, vagotomized, ganglion-blocked, captopril-treated bioassay rats. We hypothesized that intravenous infusion of β-FXIIa into intact untreated rats would elicit a qualitatively similar vasoconstrictor response. BN (Brown Norway) rats received for 60 min either: (i) saline (control; n=10); (ii) β-FXIIa (85 ng/min per kg of body weight; n=9); or (iii) β-FXIIa after 2ADX (bilateral adrenalectomy; n=9). LV (left ventricular) volume and aortic BP were recorded before (30 min baseline), during (60 min) and after (30 min recovery) the infusion. TPR (total peripheral resistance) was derived from MAP (mean arterial pressure), SV (stroke volume) and HR. Saline had no haemodynamic effects. β-FXIIa infusion increased its plasma concentration 3-fold in both groups. In adrenally intact rats, β-FXIIa infusion increased MAP by 6% (5±2 mmHg) and TPR by 45% (0.50±0.12 mmHg/ml per min), despite falls in SV (−38±8 μl) and HR [−18±5 b.p.m. (beats/min)] (all P<0.05). In 2ADX rats, β-FXIIa had no HR effect, but decreased SV (−89±9 μl) and MAP (−4±1 mmHg), and increased TPR by 66% (0.59±0.15 mmHg/ml per min) (all P<0.05). After infusion, adrenally intact rats exhibited persistent vasoconstriction (MAP, 10±1 mmHg; TPR, 0.55±0.07 mmHg/ml per min; both P<0.05), whereas in 2ADX rats, MAP remained 5±1 mmHg below baseline (P<0.05) and TPR returned to baseline. End-study arterial adrenaline (epinephrine) concentrations in the three groups were 1.9±0.6, 9.8±4.1 and 0.6±0.2 nmol/l respectively. Thus, in neurally intact lightly anaesthetized untreated rats, β-FXIIa infusion induces both adrenal catecholamine-mediated and adrenally independent increases in peripheral resistance.
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Hirsch D, Zukowska Z. NPY and stress 30 years later: the peripheral view. Cell Mol Neurobiol 2012; 32:645-59. [PMID: 22271177 DOI: 10.1007/s10571-011-9793-z] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 12/26/2011] [Indexed: 02/06/2023]
Abstract
Almost 30 years ago, neuropeptide Y (NPY) was discovered as a sympathetic co-transmitter and one of the most evolutionarily conserved peptides abundantly present all over the body. Soon afterward, NPY's multiple receptors were characterized and cloned, and the peptide's role in stress was first documented. NPY has proven to be pivotal for maintaining many stress responses. Most notably, NPY is known for activating long-lasting vasoconstriction in many vascular beds, including coronary arteries. More recently, NPY was found to play a role in stress-induced accretion of adipose tissue which many times can lead to detrimental metabolic changes. It is however due to its prominent actions in the brain, one of which is its powerful ability to stimulate appetite as well as its anxiolytic activities that NPY became a peptide of importance in neuroscience. In contrast, its actions in the rest of the body, including its role as a stress mediator, remained, surprisingly underappreciated and not well understood. Our research has focused on that other, "peripheral" side of NPY. In this review, we will discuss those actions of NPY on the cardiovascular system and metabolism, as they relate to adaptation to stress, and attempt to both distinguish NPY's effects from and integrate them with the effects of the classical stress mediators, glucocorticoids, and catecholamines. To limit the bias of someone (ZZ) who has viewed the world of stress through the eyes of NPY for over 20 years, fresh insight (DH) has been solicited to more objectively assess NPY's contributions to stress-related diseases and the body's ability to adapt to stress.
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Affiliation(s)
- Dalay Hirsch
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455, USA.
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Ream MA, Chandra R, Peavey M, Ray AM, Roffler-Tarlov S, Kim HG, Wetsel WC, Rockman HA, Chikaraishi DM. High oxygen prevents fetal lethality due to lack of catecholamines. Am J Physiol Regul Integr Comp Physiol 2008; 295:R942-53. [PMID: 18635452 DOI: 10.1152/ajpregu.00860.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The catecholamine norepinephrine is required for fetal survival, but its essential function is unknown. When catecholamine-deficient [tyrosine hydroxylase (Th) null] mouse fetuses die at embryonic day (E)13.5-14.5, they resemble wild-type (wt) fetuses exposed to hypoxia. They exhibit bradycardia (28% reduction in heart rate), thin ventricular myocardium (20% reduction in tissue), epicardial detachment, and death with vascular congestion, hemorrhage, and edema. At E12.5, before the appearance of morphological deficits, catecholamine-deficient fetuses are preferentially killed by experimentally induced hypoxia and have lower tissue Po(2) levels than wt siblings. By microarray analysis (http://www.ncbi.nlm.nih.gov/geo; accession no. GSE10341), hypoxia-inducible factor-1 target genes are induced to a greater extent in null fetuses than in wt siblings, supporting the notion that mutants experience lower oxygen tension or have an enhanced response to hypoxia. Hypoxia induces a 13-fold increase in plasma norepinephrine levels, which would be expected to increase heart rate, thereby improving oxygen delivery in wt mice. Surprisingly, increasing maternal oxygen (inspired O(2) 33 or 63%) prevents the effects of catecholamine deficiency, restoring heart rate, myocardial tissue, and survival of Th null fetuses to wt levels. We suggest that norepinephrine mediates fetal survival by maintaining oxygen homeostasis.
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Affiliation(s)
- Margie A Ream
- Dept. of Neurobiology, Box 3209, Duke Univ. Medical Center, Durham, NC 27710, USA
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Role of neuronal nitric oxide synthase in the regulation of the neuroendocrine stress response in rodents: insights from mutant mice. Amino Acids 2008; 35:17-27. [DOI: 10.1007/s00726-007-0630-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 10/31/2007] [Indexed: 02/04/2023]
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Sikter A, Frecska E, Braun IM, Gonda X, Rihmer Z. The role of hyperventilation: hypocapnia in the pathomechanism of panic disorder. REVISTA BRASILEIRA DE PSIQUIATRIA 2007; 29:375-9. [PMID: 17713689 DOI: 10.1590/s1516-44462006005000048] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Accepted: 04/02/2007] [Indexed: 11/22/2022]
Abstract
OBJECTIVE: The authors present a profile of panic disorder based on and generalized from the effects of acute and chronic hyperventilation that are characteristic of the respiratory panic disorder subtype. The review presented attempts to integrate three premises: hyperventilation is a physiological response to hypercapnia; hyperventilation can induce panic attacks; chronic hyperventilation is a protective mechanism against panic attacks. METHOD: A selective review of the literature was made using the Medline database. Reports of the interrelationships among panic disorder, hyperventilation, acidosis, and alkalosis, as well as catecholamine release and sensitivity, were selected. The findings were structured into an integrated model. DISCUSSION: The panic attacks experienced by individuals with panic disorder develop on the basis of metabolic acidosis, which is a compensatory response to chronic hyperventilation. The attacks are triggered by a sudden increase in (pCO2) when the latent (metabolic) acidosis manifests as hypercapnic acidosis. The acidotic condition induces catecholamine release. Sympathicotonia cannot arise during the hypercapnic phase, since low pH decreases catecholamine sensitivity. Catecholamines can provoke panic when hyperventilation causes the hypercapnia to switch to hypocapnic alkalosis (overcompensation) and catecholamine sensitivity begins to increase. CONCLUSION: Therapeutic approaches should address long-term regulation of the respiratory pattern and elimination of metabolic acidosis.
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Affiliation(s)
- Andras Sikter
- Department of Internal Medicine, St. Rokus Hospital, Budapest, Hungary
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Feenstra MG. Dopamine and noradrenaline release in the prefrontal cortex in relation to unconditioned and conditioned stress and reward. PROGRESS IN BRAIN RESEARCH 2001; 126:133-63. [PMID: 11105645 DOI: 10.1016/s0079-6123(00)26012-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- M G Feenstra
- Netherlands Institute for Brain Research, Amsterdam, The Netherlands.
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Kobayashi K, Morita S, Mizuguchi T, Sawada H, Yamada K, Nagatsu I, Fujita K, Nagatsu T. Functional and high level expression of human dopamine beta-hydroxylase in transgenic mice. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)43941-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Fillenz M, Stanford SC, Coles BG. Changes in sympathetic nerve terminals in the heart of cold-exposed rats. J Neurochem 1993; 61:132-7. [PMID: 8515259 DOI: 10.1111/j.1471-4159.1993.tb03547.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Changes in sympathetic nerve terminals of the heart after varying periods of exposure of rats to 4 degrees C were investigated. Two indices were used for changes in the number of noradrenaline storage vesicles, i.e., vesicular dopamine beta-hydroxylase (DBH) activity and noradrenaline storage capacity. The latter was obtained after uptake of [3H]noradrenaline; endogenous content, uptake of exogenous noradrenaline, and degree of saturation of the vesicles were calculated using the specific activity of the [3H]noradrenaline. As a measure of tyrosine hydroxylase activity, whole ventricular noradrenaline, dopamine, and dihydroxyphenylacetic acid content were used. After 4 h of cold exposure there was an increase in vesicular endogenous noradrenaline content, uptake, storage capacity, and DBH activity as well as a large increase in whole ventricular dopamine. After 6 h in the cold, vesicular endogenous noradrenaline content, storage capacity, and DBH activity were decreased. The results suggest that during cold exposure there is an initial increase followed by a decrease in the number of functional vesicles in the nerve terminal, which could explain the fluctuations in the rate of noradrenaline release.
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Affiliation(s)
- M Fillenz
- University Laboratory of Physiology, Oxford, England
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Keeton TK, Biediger AM. The measurement of norepinephrine clearance and spillover rate into plasma in conscious spontaneously hypertensive rats. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1988; 338:350-60. [PMID: 3244380 DOI: 10.1007/bf00172109] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The clearance of norepinephrine from plasma and the spillover rate of norepinephrine into plasma were determined in conscious unrestrained spontaneously hypertensive rats by measuring the concentrations of 3H-norepinephrine and norepinephrine in arterial plasma after 90 min of i.v. infusion with 3H-norepinephrine. In 50 conscious spontaneously hypertensive rats treated with saline (control animals), the following basal values were obtained: plasma norepinephrine concentration = 149 +/- 5 pg/ml; plasma epinephrine concentration = 61 +/- 4 pg/ml; norepinephrine clearance = 188 +/- 4 ml min-1 kg-1; and norepinephrine spillover rate = 27.5 +/- 0.8 ng min-1 kg-1. A significant portion of infused 3H-norepinephrine appeared to be cleared from the plasma by the uptake1 process, since desipramine decreased norepinephrine clearance by 32%. The vasodilating agents hydralazine and minoxidil produced dose-related increases in norepinephrine spillover rate and plasma norepinephrine concentration, but the percent increases in norepinephrine spillover rate exceeded the percent increases in plasma norepinephrine concentration because of concomitant increases in norepinephrine clearance, particularly after treatment with minoxidil. The increase in norepinephrine clearance caused by hydralazine and minoxidil probably resulted from the increase in cardiac output and resultant increase in hepatic and/or pulmonary blood flow. Adrenal secretion of norepinephrine did not appear to contribute to the elevation in norepinephrine spillover rate elicited by hydralazine and minoxidil. Chlorisondamine suppressed norepinephrine spillover rate by 77%, in association with a 70% decline in plasma epinephrine concentration, whereas bretylium lowered norepinephrine spillover rate by only 41%, with no change in plasma epinephrine concentration. The decrements in norepinephrine clearance caused by chlorisondamine (-23%) and bretylium (-15%) were more or less proportional to the magnitude of the vasodepression caused by these drugs. Both norepinephrine spillover rate and clearance fell in a dose-related fashion after treatment with clonidine. After treatment with the sympathoinhibitory agents chlorisondamine, bretylium and clonidine, the percent decreases in norepinephrine spillover rate always exceeded the percent decreases in plasma norepinephrine concentration. Based on these observations, we conclude that norepinephrine spillover rate provides a more accurate measurement of the activity of the peripheral sympathetic nervous system than does plasma norepinephrine concentration in conscious spontaneously hypertensive rats.
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Affiliation(s)
- T K Keeton
- Department of Pharmacology, University of Texas Health Science Center, San Antonio 78284
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Le Noble LM, Tangelder GJ, Slaaf DW, Smits JF, Struyker-Boudier HA. Adrenergic stimulation of the rat mesenteric vascular bed: a combined micro- and macrocirculatory study. Pflugers Arch 1987; 410:250-6. [PMID: 3684512 DOI: 10.1007/bf00580273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The sympathetic nervous system is one of the primary factors controlling vascular resistance. Vascular smooth muscle contraction by sympathetic stimulation is mediated primarily by alpha-adrenoceptors. In this study, we investigated the effects of different forms of adrenergic stimulation on simultaneously measured macro- and microcirculatory dynamics in the rat mesenteric vascular bed. Macrocirculatory effects were measured by means of registration of changes in mean arterial pressure (MAP) and blood flow feeding this tissue via a miniaturized Doppler flow probe around the superior mesenteric artery. Microvascular changes were measured at the level of A2 arterioles by means of intravital microscopic registration of arteriolar diameters and red blood cell velocity (RBC vel). Topical or intra-arterial application of noradrenaline caused a dose-dependent decrease in arteriolar diameter and RBC vel at doses that did not cause significant systemic effects. On the other hand, during intravenous application of noradrenaline or other vasopressor substances an increase in MAP and decrease in organ (Doppler) blood flow was not parallelled by a decrease in arteriolar diameter or RBC vel. In contrast, RBC vel increased in a dose-related manner, whereas arteriolar diameter only secondarily decreased to a small degree. Similar results were obtained when the sympathetic nervous system was activated by means of electrical stimulation of the posterior hypothalamus. These data indicate that adrenergic stimulation can elicit different vascular responses. The ultimate microvascular effect depends upon the way of stimulation or route of drug administration.
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Affiliation(s)
- L M Le Noble
- Department of Pharmacology, University of Limburg, Maastricht, The Netherlands
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Le Bras YM. Circadian variations of catecholamine levels in brain, heart, and plasma in the eel, Anguilla anguilla L., at three different times of year. Gen Comp Endocrinol 1984; 55:472-9. [PMID: 6468922 DOI: 10.1016/0016-6480(84)90020-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The amounts of catecholamine (dopamine, adrenaline, and noradrenaline) in the brain, heart, and plasma of the eel (Anguilla anguilla L.) during a 24-hr period and at three different times of year were determined by using a radioenzymatic method. Seasonal variations of catecholamine average values were found to be different when considering catecholamine levels in the same tissue (one exception: heart levels in May) or the same amine in different tissues. Circadian rhythms of catecholamine levels were evident only in the brain; the maximum amount generally occurred during the light phase. No correlation could be found between the 24-hr variations in the different tissues. The most important variations were phased with the dark-light cycle but were also dependent on the annual cycle.
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Speth RC, Khosla MC, Spech MM, Ferrario CM. Rat (Ile5) but not bovine (Val5) angiotensin raises plasma norepinephrine in rats. Hypertension 1981; 3:II-25-9. [PMID: 7298141 DOI: 10.1161/01.hyp.3.6_pt_2.ii-25] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A part of the vasoconstrictor activity of angiotensin II (AII) may result from its ability to enhance norepinephrine (NE) release from sympathetic noradrenergic nerve terminals. To investigate this proposed pressor mechanism of AII, the effects of intravenous (i.v.) infusion of AII on blood pressure and plasma catecholamines in pithed rats were determined. Two naturally occurring angiotensins, valine5 AII (bovine) and isoleucine5 AII (rat), were administered in equal (72 ng/min) doses. Valine5 AII caused an 80% increase in mean arterial pressure (MAP) from 54 +/- 4 to 97 +/- 19 mm Hg. Isoleucine5 AII caused an 82% increase in MAP from 49 +/- 5 to 89 +/- 18 mm Hg. Neither angiotensin caused a change in heart rate, suggesting that pithing completely destroyed the central baroreceptor reflex mechanism. Plasma catecholamines were differentially affected by the peptides:isoleucine5 AII significantly increased plasma NE concentration by 82% compared to saline-infused rats (p less than 0.01). Valine5 AII did not significantly affect plasma NE concentration. Plasma dopamine and epinephrine concentrations were not significantly altered by infusion of either analog. Despite the significant increases in plasma NE concentrations with isoleucine5 in AII-infusion rats, there was no correlation between plateau MAP or the percent increase in MAP and plasma NE concentrations of individual animals within this group. The ability of angiotensin to elevate MAP, increase NE release from sympathetic nerve terminals, as well as potential differences in the actions of angiotensins in different species, and angiotensin receptor heterogeneity, are discussed.
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Carruba MO, Picotti GB, Miodini P, Lotz W, Da Prada M. Blood sampling by chronic cannulation technique for reliable measurements of catecholamines and other hormones in plasma of conscious rats. JOURNAL OF PHARMACOLOGICAL METHODS 1981; 5:293-303. [PMID: 7311568 DOI: 10.1016/0160-5402(81)90041-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
An optimalized technique for chronic venous and arterial cannulation of rodents that permits repeated blood collections in unstressed, freely moving animals is presented. The indwelling catheter can also be used for chronic and/or acute drug administration in rats or other small laboratory animals, as well as for the recording of blood pressure and heart rate. The attachment device of minimal size is easily fixed on the head of the animals, allowing the additional implantation of a chronic cannula for intracerebral injections. No residual effects on the resting levels of plasma catecholamines (CA) were present 24-hr after surgery and anesthesia for implanting the cannula. No variations of plasma CA concentrations were observed at the different times of day examined or as a consequence of withdrawal of subsequent blood samples. Training the animals to be handled prevented the increase in plasma prolactin levels produced by decapitation; training had no influence on the decapitation-induced rises in plasma CA concentrations.
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Abstract
1. Cold exposure caused a marked decrease in insulin response to intravenous injection of glucose, with a sharply declining response over the first 4 days of cold exposure followed by a constant low response up to 13 days of the experimental cold period. 2. The glucose-induced insulin response was unaffected by concomitant infusion of phentolamine in the warm environment. In contrast, the low response of insulin secretion to glucose during cold exposure was so augmented by concomitant infusion of phentolamine as to exceed the response observed in the warm environment. 3. Intravenous infusion of phentolamine caused an increase in the concentration of plasma insulin in the cold but not in the warm environment. 4. Adrenaline completely abolished the insulin response to glucose in the warm environment. 5. Exposure to cold environment brought about an increase in urinary excretion of adrenaline and noradrenaline and in heart rate, but rectal temperature was unchanged. 6. It is concluded that cold exposure insufficient to cause hypothermia produces a marked decrease in insulin secretion by the pancreas of sheep, mediated through adrenergic alpha-receptors stimulated by augmented sympatho-adrenomedullary activity.
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Abstract
Plasma concentrations of adrenaline and noradrenaline were measured sequentially over the immediate post-operative period following clipping of an intracranial aneurysm in 11 patients. Those patients who developed local cerebral vasospasm showed a sustained rise in plasma catecholamines, particularly noradrenaline, whilst those patients who developed generalised cerebral vasospasm showed early peaks of very high concentrations of adrenaline and noradrenaline which preceded radiological evidence of generalized vasospam.
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23
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Badian M, Appel E, Palm D, Rupp W, Sittig W, Taeuber K. Standardized mental stress in healthy volunteers induced by delayed auditory feedback (DAF). Eur J Clin Pharmacol 1979; 16:171-6. [PMID: 499316 DOI: 10.1007/bf00562057] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Using delayed auditory feedback (delay 0.175 s) a standardized form of mental stress was investigated in 8 healthy male volunteers. After a resting period and a period of undelayed reading, the volunteers were exposed for 5 min to the DAF stress. During the DAF period heart rate increased by 10% and systolic and diastolic blood pressure increased by 9% and 18%, respectively. As a measure of acute sympathetic activation, plasma concentrations of norepinephrine and epinephrine rose by 68% and 49%, respectively. The activity od dopamine-beta-hydroxylase in plasma was increased by 25%. From these results it can be concluded that the DAF procedure provides a suitable method for inducing a standardized mental stress in normal subjects, which can be measured as changes in biochemical and cardiovascular variables.
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Benedict CR, Fillenz M, Stanford C. Noradrenaline release in rats during prolonged cold-stress and repeated swim-stress. Br J Pharmacol 1979; 66:521-4. [PMID: 465891 PMCID: PMC2043586 DOI: 10.1111/j.1476-5381.1979.tb13689.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
1 Plasma noradrenaline concentration in rats was measured during prolonged cold-stress and repeated swim-stress. 2 Cold exposure for 6 h caused a rise in plasma noradrenaline which reached a peak at 4 h. 3 Administration of desmethylimipramine and normetanephrine to block neuronal and extra-neuronal uptake of noradrenaline raised plasma noradrenaline concentration without changing the pattern of the response to cold exposure. 4 Repeated cold exposure on subsequent days produced no change in the pattern of plasma noradrenaline concentration. 5 Five successive 1-min swims at 30-min intervals caused a rise in plasma noradrenaline concentration which was maximal after the third swim. 6 It is suggested that prolonged and repeated activation of sympathetic nerve terminals leads to a decline in noradrenaline release.
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Little RA. Effects of non-haemorrhagic injury on the cardiovascular response to tilting in the rat. BRITISH JOURNAL OF EXPERIMENTAL PATHOLOGY 1979; 60:309-13. [PMID: 475977 PMCID: PMC2041455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the unanaesthetized uninjured rat a head-up tilt elicited a pressor response, the magnitude of which was directly related to the angle of tilt. The pressor response was reduced by a 4 h period of bilateral hind-limb ischaemia and by a non-fatal scald, although the slope of the regression line relating percentage rise in mean arterial blood pressure to the angle of tilt was unaltered. The degree of impairment of the response was directly related to the severity of the injury. In the uninjured rat there was a sigmoid relationship between the angle of tilt and the mean heart rate during the tilt. No relationship could be demonstrated between angle of tilt and heart rate in the injured rats.
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