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Griffiths PR, Lolait SJ, Pearce LE, McBryde FD, Paton JFR, O'Carroll AM. Blockade of Rostral Ventrolateral Medulla Apelin Receptors Does Not Attenuate Arterial Pressure in SHR and L-NAME-Induced Hypertensive Rats. Front Physiol 2018; 9:1488. [PMID: 30459635 PMCID: PMC6232890 DOI: 10.3389/fphys.2018.01488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/02/2018] [Indexed: 01/02/2023] Open
Abstract
Dysfunction of the apelinergic system, comprised of the neuropeptide apelin mediating its effects via the G protein-coupled apelin receptor (APJ), may underlie the onset of cardiovascular disease such as hypertension. Apelin expression is increased in the rostral ventrolateral medulla (RVLM) in spontaneously hypertensive rats (SHRs) compared to Wistar-Kyoto (WKY) normotensive rats, however, evidence that the apelinergic system chronically influences mean arterial blood pressure (MABP) under pathophysiological conditions remains to be established. In this study we investigated, in conscious unrestrained rats, whether APJ contributes to MABP and sympathetic vasomotor tone in the progression of two models of hypertension - SHR and L-NAME-treated rats - and whether APJ contributes to the development of hypertension in pre-hypertensive SHR. In SHR we showed that APJ gene (aplnr) expression was elevated in the RVLM, and there was a greater MABP increase following microinjection of [Pyr1]apelin-13 to the RVLM of SHR compared to WKY rats. Bilateral microinjection of a lentiviral APJ-specific-shRNA construct into the RVLM of WKY, SHR, and L-NAME-treated rats, chronically implanted with radiotelemeters to measure MABP, decreased aplnr expression in the RVLM and abolished acute [Pyr1]apelin-13-induced increases in MABP. However, chronic knockdown of aplnr in the RVLM did not affect MABP in either SHR or L-NAME-treated rats. Moreover, knockdown of aplnr in the RVLM of prehypertensive SHR did not protect against the development of hypertension. These results show that endogenous apelin, acting via APJ, is not involved in the genesis or maintenance of hypertension in either animal model used in this study.
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Affiliation(s)
- Philip R Griffiths
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Stephen J Lolait
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Louise E Pearce
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Fiona D McBryde
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Anne-Marie O'Carroll
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
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Widegren U, Hickner RC, Jorfeldt L, Henriksson J. Muscle blood flow response to mental stress and adrenaline infusion in man: microdialysis ethanol technique compared to (133)Xe clearance and venous occlusion plethysmography. Clin Physiol Funct Imaging 2010; 30:152-61. [PMID: 20113316 DOI: 10.1111/j.1475-097x.2009.00919.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIM Adrenaline, administered locally by microdialysis in skeletal muscle, causes vasoconstriction around the microdialysis catheter. This is contrary to the vasodilation that normally occurs when adrenaline is infused intravenously or intra-arterially. The hypothesis was tested that vasoconstriction, measured by microdialysis, would not occur with two interventions causing increased plasma levels of adrenaline, mental stress and intravenous adrenaline infusion (0.1 nmol kg(-1) min(-1)). METHODS Twenty-four men (27 +/- 1.6 years) underwent these interventions. Blood flow was determined by the microdialysis ethanol technique and (133)Xe clearance (gastrocnemius muscle, medial head) and by venous occlusion plethysmography (calf). RESULTS The ethanol outflow/inflow ratio, which is inversely related to blood flow, decreased to 92.0 +/- 3.4% of basal, P = 0.014 (mean +/- SEM, n = 16) during the mental stress test, but increased to 108.3 +/- 2.2% of basal, P = 0.001 (n = 16) during the adrenaline infusion. The latter increase was abolished when adrenaline was infused during alpha-receptor blockade by phentolamine. On the contrary, by (133)Xe clearance and venous occlusion plethysmography, blood flow increased during both interventions; 2.0-1.7-fold (mental stress) and 1.3-1.4-fold (adrenaline infusion), respectively, P<0.05. CONCLUSION Adrenaline causes vasoconstriction in skeletal muscle when blood flow is measured with the microdialysis ethanol technique, irrespective of the mode of administration. The discrepant blood flow result obtained with the microdialysis ethanol technique might, at least partly, be explained by differential diffusion properties of ethanol and (133)Xe. An additional or alternative explanation might be that an inserted microdialysis catheter shifts the balance of vasoconstrictor and vasodilator effects of adrenaline in skeletal muscle.
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Affiliation(s)
- U Widegren
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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van der Woude HJ, Aalbers R. Long-acting beta2-agonists: comparative pharmacology and clinical outcomes. ACTA ACUST UNITED AC 2005; 1:55-74. [PMID: 14720076 DOI: 10.1007/bf03257163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Salmeterol and formoterol are both long-acting beta(2)-adrenoceptor agonists (beta(2)-agonists). They both provide excellent bronchodilating and bronchoprotective effects in patients with asthma but their are some differences between these two long-acting beta(2)-agonists in vitro and in vivo. Formoterol has a greater potency and intrinsic activity than salmeterol, which can become especially apparent at higher doses than that clinically recommended, and in contracted bronchi. Long-term use of long-acting beta(2)-agonists can induce tolerance, which can be partially reversed with corticosteroids. Long-acting beta(2)-agonists have some anti-inflammatory effects in vitro, but data in vivo are less convincing. Compared with doubling the dose of inhaled corticosteroids, the addition of inhaled long-acting beta(2)-agonists to inhaled corticosteroids improves symptom control in patients with asthma and reduces both the exacerbation rate of asthma and hospital admission rate. No enhanced airway responsiveness or loss of perception of dyspnea has been observed with the use of inhaled long-acting beta(2)-agonists. Monotherapy with long-acting beta(2)-agonists is not recommended.
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Affiliation(s)
- Hanneke J van der Woude
- Department of Pulmonary Diseases, Martini Hospital, Postbus 30033, 9700 RM Groningen, The Netherlands.
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Taylor DA, Jensen MW, Aikman SL, Harris JG, Barnes PJ, O'Connor BJ. Comparison of salmeterol and albuterol-induced bronchoprotection against adenosine monophosphate and histamine in mild asthma. Am J Respir Crit Care Med 1997; 156:1731-7. [PMID: 9412548 DOI: 10.1164/ajrccm.156.6.9703047] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Short-acting beta(2)-agonists provide greater protection to bronchoconstriction induced by adenosine-5'-monophosphate (AMP) than does methacholine. Because AMP produces bronchoconstriction through release of mediators from mast cells, and methacholine directly constricts airway smooth muscle, this suggests that beta(2)-agonists stabilize mast cells in vivo. This in vivo property has not been demonstrated with long-acting beta(2)-agonists. We undertook two double-blind, randomized, crossover, placebo-controlled studies to investigate the effects of salmeterol and albuterol on airway responsiveness (AR) to AMP and histamine in patients with mild asthma. In the first study, 19 patients attended on four occasions to inhale salmeterol 50 micrograms or placebo 2 h before challenge with AMP or histamine. In the second study 16 patients (13 of whom had participated in the first study) were studied in a similar fashion but inhaled albuterol 400 micrograms or placebo 30 min prior to challenge. Salmeterol reduced AR to AMP and histamine by 3.4 +/- 0.3 and 3.9 +/- 0.3 doubling doses, respectively (NS). In contrast, albuterol demonstrated a greater protective effect on AMP than on histamine, reducing AR by 5.1 +/- 0.3 and 3.8 +/- 0.2 doubling doses, respectively (p < 0.005). Thus, in contrast to albuterol, salmeterol did not demonstrate mast-cell stabilizing properties in vivo at a time corresponding to maximal bronchodilatation. These findings might be explained by the unique pharmacologic profile of salmeterol in combination with the differential beta(2)-adrenoceptor pharmacology of bronchial mast cells and bronchial smooth muscle.
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Affiliation(s)
- D A Taylor
- Royal Brompton Clinical Studies Unit, Department of Thoracic Medicine, Imperial College School of Medicine, London, United Kingdom
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Sun LS, Pantuck CB, Morelli JJ, Khambatta GH, Tierney AC, Quaegebeur JM, Smiley RM. Perioperative lymphocyte adenylyl cyclase function in the pediatric cardiac surgical patient. Crit Care Med 1996; 24:1654-9. [PMID: 8874301 DOI: 10.1097/00003246-199610000-00009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To examine intraoperative and postoperative lymphocyte adenylyl cyclase activities in children undergoing repair of congenital cardiac defects with hypothermic cardiopulmonary bypass. DESIGN A prospective study. SETTING Tertiary university pediatric hospital. PATIENTS Twelve children were enrolled into the study to examine intraoperative lymphocyte adenylyl cyclase activities and 12 children were enrolled to examine postoperative lymphocyte adenylyl cyclase activities. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Basal (unstimulated), isoproterenol, and prostaglandin E-1 stimulated adenylyl cyclase activities, and plasma norepinephrine and epinephrine concentrations were measured. Intraoperative basal (unstimulated), beta-adrenergic receptor-stimulated (in response to isoproterenol), and prostaglandin E1 (PGE1)-stimulated lymphocyte adenylyl cyclase activities all increased during cardiopulmonary bypass, then decreased immediately after cardiopulmonary bypass. In the postoperative group, a significant decrease in basal (unstimulated), beta-adrenergic receptor- and PGE1-stimulated adenylyl cyclase activities were observed on postoperative day 1 as compared with precardiopulmonary bypass values. CONCLUSIONS In the pediatric cardiac surgical patient, there was an intraoperative enhancement of lymphocyte adenylyl cyclase activities. This increase in adenylyl cyclase activities was followed by reduced lymphocyte adenylyl cyclase activities, including beta-adrenergic receptor desensitization, postoperatively, as we have previously documented in adults.
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Affiliation(s)
- L S Sun
- Department of Anesthesiology, Collage of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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Illi A, Sundberg S, Ojala-Karlsson P, Korhonen P, Scheinin M, Gordin A. The effect of entacapone on the disposition and hemodynamic effects of intravenous isoproterenol and epinephrine. Clin Pharmacol Ther 1995; 58:221-7. [PMID: 7648772 DOI: 10.1016/0009-9236(95)90200-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Entacapone is a potent, selective catechol-O-methyltransferase (COMT) inhibitor. Entacapone could potentiate the hemodynamic effects of exogenously administered catecholamines, which are substrates of the COMT enzyme. DESIGN AND METHODS Originally, the study was to follow a placebo-controlled, randomized crossover design. Because of two cases of ventricular arrhythmia, a decision was made to terminate the study before its completion. Six subjects went through the isoproterenol and epinephrine infusions while taking placebo and five other subjects while taking entacapone. The actual design was thus one with two parallel groups with random allocation and double-blind drug administration. The subjects were given either a single dose of 400 mg entacapone or placebo 30 minutes before the start of isoproterenol or epinephrine infusions. Four dosages of epinephrine (1.5, 3, 6, or 12 micrograms/min) and isoproterenol (0.5, 1, 1.5, or 2 micrograms/min) were infused (5 minutes for each level). Heart rate and blood pressure were measured and ECG was monitored. The concentrations of isoproterenol and epinephrine in plasma were determined by HPLC. RESULTS The maximal increase in heart rate during isoproterenol infusion after entacapone administration (40 +/- 11 beats/min, mean +/- SD) was statistically greater (p = 0.0496) than after placebo administration (27 +/- 7 beats/min). The increase in heart rate during epinephrine infusion was 25 +/- 13 beats/min after entacapone administration and 14 +/- 9 beats/min after placebo administration (p = 0.127). There were no statistically significant differences between entacapone and placebo in blood pressure or in plasma concentrations of isoproterenol and epinephrine. CONCLUSION We conclude that entacapone may potentiate the chronotropic and arrhythmogenic effects of exogenously administered isoproterenol and epinephrine.
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Affiliation(s)
- A Illi
- Orion Research Center, Orion-Farmos, Espoo, Finland
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Marsland AL, Manuck SB, Wood P, Rabin BS, Muldoon MF, Cohen S. Beta 2-adrenergic receptor density and cardiovascular response to mental stress. Physiol Behav 1995; 57:1163-7. [PMID: 7652038 DOI: 10.1016/0031-9384(94)00378-i] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In this study we evaluated effects of an acute experimental stressor on beta 2-adrenoceptor density and examined the relationships of baseline receptor density to cardiovascular reactions induced by stress. In addition, we investigated whether any observed alterations in receptor density were associated with concomitant redistribution of circulating lymphocyte populations. Receptor density and lymphocyte subsets were determined before and immediately following performance of a frustrating laboratory task in 22 male volunteers. Blood pressure, heart rate (HR), and plasma catecholamine concentrations were also assessed at baseline and during task performance. Parallel measurements were obtained among 11 unstressed control subjects. Receptor density increased significantly between baseline and posttask measurements, but equally so in experimental and control subjects. Numbers of T suppressor/cytotoxic and natural killer cells increased selectively among subjects assigned to the experimental (stress) condition. However, there was no association between lymphocyte subset distribution and receptor density. Interindividual variability in pretask receptor density correlated significantly with heart rate and systolic blood pressure (SBP) reactivity during the initial 3 min of mental stress, but not over the entire task period. In addition, baseline receptor density correlated with SBP (but not HR) reactivity after covariance adjustment for the concomitant change in plasma catecholamine concentrations.
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Affiliation(s)
- A L Marsland
- Department of Psychology, University of Pittsburgh, PA 15213, USA
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Van Dijk G, Balkan B, Lindfeldt J, Bouws G, Scheurink AJ, Ahrén B, Steffens AB. Contribution of liver nerves, glucagon, and adrenaline to the glycaemic response to exercise in rats. ACTA PHYSIOLOGICA SCANDINAVICA 1994; 150:305-13. [PMID: 7912034 DOI: 10.1111/j.1748-1716.1994.tb09691.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The contribution of hepatic sympathetic innervation, glucagon and adrenaline to the glycaemic response to exercise was investigated in rats. Hepatically denervated (LDX) or sham operated (SHAM) rats with permanent catheters were therefore submitted to swimming with or without infusion of somatostatin in combination with adrenodemedullation. Blood samples were taken for measurements of blood glucose, plasma free fatty acids (FFA), adrenaline (A), noradrenaline (NA), insulin and glucagon. Liver denervation by itself did not influence glucose levels during exercise. Infusion of somatostatin in SHAM animals, which inhibited the exercise-induced glucagon response, led to enhanced sympathoadrenal outflow (measured as plasma A and NA) and a reduced blood glucose during exercise, suggesting that glucagon serves as a powerful mediator of the glycaemic response during swimming. Infusion of somatostatin in LDX animals failed to enhance plasma NA levels and led to a more pronounced reduction in blood glucose levels. This indicates that liver nerves do contribute to the glycaemic response to exercise when glucagon secretion is suppressed. Reduced blood glucose levels after adrenodemedullation revealed that adrenal A is another important mediator of the glucose response to exercise. Infusion of somatostatin in adrenodemedullated SHAM or LDX animals was not accompanied with increased NA outflow, suggesting that adrenal A is necessary to allow the compensatory increased outflow of NA from sympathetic nerves. In conclusion, the study shows that pancreatic glucagon and adrenal A are the predominant factors influencing the glycaemic response to exercise, whereas a role of the sympathetic liver nerves becomes evident when glucagon secretion is suppressed.
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Affiliation(s)
- G Van Dijk
- Department of Animal Physiology, University of Groningen, The Netherlands
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Chi DS, Neumann JK, Mota-Marquez M, Dubberley FA. Effects of acute stress on lymphocyte beta 2-adrenoceptors in white males. J Psychosom Res 1993; 37:763-70. [PMID: 8229907 DOI: 10.1016/0022-3999(93)90105-o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of acute cold pressor stress on peripheral blood cells and lymphocyte beta 2-adrenoceptor density and affinity were examined in 18 young, healthy normal white male volunteers. Blood samples were drawn two times before and three times after the stressor. The percents of lymphocytes and neutrophils, plasma cortisol and the beta 2-adrenoceptor density were significantly different among blood samples. There were no differences between samples in total white blood cell count, and percent of monocyte, basophil and eosinophil or beta 2-adrenoceptor affinity. The results suggest that cold pressor stress causes lymphocytosis and increases the lymphocytic beta 2-adrenoceptors concentration. Methodological issues, acute vs chronic condition effects, immune cell subset variations and the psychosomatic activity-affect model were discussed. Such adrenoceptor changes may provide one mechanism by which stress can affect the onset of cardiac/hypertensive disorders.
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Affiliation(s)
- D S Chi
- Department of Internal Medicine, James H. Quillen College of Medicine, East Tennessee State University, Johnson City 37614
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Anhäupl T, Liebl B, Trunk E, Träger K, Ensinger H, Georgieff M. Evidence for inverse regulation of high and low affinity binding sites for (-)125iodocyanopindolol in human mononuclear leucocytes during epinephrine infusion. JOURNAL OF RECEPTOR RESEARCH 1993; 13:355-67. [PMID: 8383758 DOI: 10.3109/10799899309073666] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
As we have shown earlier (-)125Iodocyanopindolol (125ICYP) binding to beta-adrenoceptors (beta-AR) in human mononuclear leucocytes (MNL) yields evidence for the existence of high affinity (Bhiaff) and low affinity (Bloaff) binding sites. We studied the regulation of these 2 classes of binding sites during 240 min of (-)-epinephrine (EPI) infusion (0.1 microgram/kg/min) (n = 8) in male healthy volunteers. Saturation experiments were performed on MNL membranes with 125ICYP over a large concentration range (1-550 pmol/l). Binding parameters were calculated by computer analysis assuming 2 classes of binding sites. We found a preinfusion value of 830 +/- 50 [sites/cell] (KD = 1.5 +/- 0.2 pmol/l) of Bhiaff binding sites and 5210 +/- 510 [sites/cell] (KD = 420 +/- 80 pmol/l) of Bloaff. During EPI infusion we observed biphasic modulation of the Bhiaff and an inverse modulation of the Bloaff. After 40 min of EPI Bhiaff increased to 1970 +/- 280 [sites/cell] (KD = 4.2 +/- 0.8 pmol/l), whereas Bloaff decreased to 2720 +/- 280 [sites/cell] (KD = 140 +/- 70 pmol/l); despite constant plasma epinephrine concentration (PEC) after 240 min of EPI Bhiaff changed to 1310 +/- 240 [sites/cell] (KD = 2.8 +/- 1.0 pmol/l) vs. 4370 +/- 760 [sites/cell] (KD = 190 +/- 100 pmol/l) Bloaff. These results suggest an interdependent inverse modulation of the 2 classes of binding sites for 125ICYP on MNL during EPI infusion.
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Affiliation(s)
- T Anhäupl
- Universitätsklinik für Anästhesiologie, Universität Ulm, Germany
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Abstract
We review the recent literature examining lipid changes during stressful experiences, and the psychological and constitutional differences that influence lipid levels at rest and that may modulate lipid response to stress. Mild forms of chronic or episodic stress are apparently not associated with alterations in lipids and lipoproteins, but severe forms of real or perceived stress do appear to alter lipid levels. Acute laboratory stress is frequently associated with short-term alterations in lipids and lipoproteins, but the significance of these changes is unclear. Several individual characteristics, such as heightened neuroendocrine or autonomic reactivity to stressors, Type A component behavior, and other aspects of personality, appear to be associated with an atherogenic lipid profile. Stress may influence lipid concentrations and metabolism through a variety of physiological and behavioral mechanisms, but none have been clearly elucidated. Future research should concentrate on understanding these mechanisms.
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Affiliation(s)
- R Niaura
- Miriam Hospital/Brown University School of Medicine, Providence, RI
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Zoukos Y, Thomaides T, Pavitt DV, Leonard JP, Cuzner ML, Mathias CJ. Up-regulation of beta-adrenoceptors on circulating mononuclear cells after reduction of central sympathetic outflow by clonidine in normal subjects. Clin Auton Res 1992; 2:165-70. [PMID: 1323363 DOI: 10.1007/bf01818957] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Short term regulation of beta-adrenoceptors in peripheral blood mononuclear cells after sympathetic activation has been previously documented in normal individuals but changes after a central reduction in sympathetic activity are not known. We have studied beta-adrenoceptor number and affinity on peripheral blood mononuclear cells in normal subjects, before and after intravenous clonidine, an alpha 2-adrenoceptor agonist which lowers blood pressure predominantly by reducing central nervous system sympathetic outflow. After clonidine there was a decrease in plasma levels of noradrenaline and adrenaline, and an increase in growth hormone. There was up-regulation of beta-adrenergic receptors on peripheral blood mononuclear cells 30 and 60 min after clonidine which was related to the fall in blood pressure, noradrenaline and adrenaline levels and to the increase in growth hormone levels. The affinity of the receptors was decreased. Return to baseline values was observed after 2 h. Intracellular production of cAMP after isoproterenol stimulation demonstrated that the up-regulation was not functional. Our studies indicate short term up-regulation of beta-adrenoceptors in peripheral blood mononuclear cells after clonidine. These observations after a reduction in sympathetic activity may be of importance if they mirror the pattern of redistribution of adrenoceptors, which are present in a wide range of tissues.
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Affiliation(s)
- Y Zoukos
- Department of Neurochemistry, Multiple Sclerosis Society Laboratory, London, UK
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