Arg16/Gly β2-adrenergic receptor polymorphism alters the cardiac output response to isometric exercise

2005 ◽  
Vol 99 (5) ◽  
pp. 1776-1781 ◽  
Author(s):  
John H. Eisenach ◽  
Sunni A. Barnes ◽  
Tasha L. Pike ◽  
Lynn A. Sokolnicki ◽  
Shizue Masuki ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Arterial Pressure ◽  
Adrenergic Receptor ◽  
Cardiovascular Response ◽  
Pressor Response ◽  
Receptor Gene ◽  
Isometric Exercise ◽  
Isometric Handgrip ◽  
Β2 Adrenergic Receptor ◽  
Receptor Polymorphism

Normotensive adults homozygous for glycine (Gly) of the Arg16/Gly β2-adrenergic-receptor polymorphism have 1) greater forearm β2-receptor mediated vasodilation and 2) a higher heart rate (HR) response to isometric handgrip than arginine (Arg) homozygotes. To test the hypothesis that the higher HR response in Gly16 subjects serves to maintain the pressor response [increased cardiac output (CO)] in the setting of augmented peripheral vasodilation to endogenous catecholamines, we measured continuous HR (ECG), arterial pressure (Finapres), and CO (transthoracic echocardiography) during isometric, 40% submaximal handgrip to fatigue in healthy subjects homozygous for Gly ( n = 30; mean age ± SE: 30 ± 1.2, 13 women) and Arg ( n = 17, age 30 ± 1.6, 11 women). Resting data were similar between groups. Handgrip produced similar increases in arterial pressure and venous norepinephrine and epinephrine concentrations; however, HR increased more in the Gly group (60.1 ± 4.3% increase from baseline vs. 45.5 ± 3.9%, P = 0.03), and this caused CO to be higher (Gly: 7.6 ± 0.3 l/m vs. Arg: 6.5 ± 0.3 l/m, P = 0.03), whereas the decrease in systemic vascular resistance in the Gly group did not reach significance ( P = 0.09). We conclude that Gly16 homozygotes generate a higher CO to maintain the pressor response to handgrip. The influence of polymorphic variants in the β2-adrenergic receptor gene on the cardiovascular response to sympathoexcitation may have important implications in the development of hypertension and heart failure.

49 THE ARG16/GLY β2-ADRENERGIC RECEPTOR POLYMORPHISM ALTERS THE CARDIAC OUTPUT RESPONSE TO ISOMETRIC EXERCISE

2005 ◽  
Vol 53 (2) ◽  
pp. S395.4-S395
Author(s):  
J. H. Eisenach ◽  
T. L. Pike ◽  
R. Chettiar ◽  
A. M. Oviedo ◽  
L. A. Sokolnicki ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Adrenergic Receptor ◽  
Isometric Exercise ◽  
Output Response ◽  
Β2 Adrenergic Receptor ◽  
Receptor Polymorphism

Influence of Sympatholytic Drugs on the Cardiovascular Response to Isometric Exercise

1981 ◽  
Vol 60 (2) ◽  
pp. 139-143 ◽  
Author(s):  
S. J. Watt ◽  
R. D. Thomas ◽  
P. W. Belfield ◽  
P. W. Goldstraw ◽  
S. H. Taylor
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Subjects ◽  
Cardiovascular Response ◽  
Pressor Response ◽  
Isometric Exercise ◽  
Systemic Blood Pressure ◽  
Isometric Handgrip ◽  
Systemic Blood ◽  
Oral Doses

1. The effects of single oral doses of various sympatholytic drugs on the heart rate and blood pressure increases during isometric handgrip contraction were studied in six healthy subjects. 2. Bethanidine reduced both the systolic and diastolic increases in pressure. Clonidine reduced the systolic but not the diastolic increase. Oxprenolol alone or in combination with phentolamine or phenyoxybenzamine failed to influence the pressor response. 3. The increase in systemic blood pressure associated with sustained contraction of voluntary muscle appears to be relatively resistant to acute sympathetic adrenoreceptor blockade in man.

G16R single nucleotide polymorphism but not haplotypes of the β2-adrenergic receptor gene alters cardiac output in humans

2013 ◽  
Vol 125 (4) ◽  
pp. 191-198 ◽  
Author(s):  
Kim Z. Rokamp ◽  
Jonatan M. Staalsoe ◽  
Martin Gartmann ◽  
Anna Sletgaard ◽  
Nicolai B. Nordsborg ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Cardiac Output ◽  
Adrenergic Receptor ◽  
Receptor Gene ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Model Flow ◽  
Genes Encoding ◽  
Β2 Adrenergic Receptor ◽  
Cardiovascular Variables

Variation in genes encoding the β2-adrenergic receptor (ADRB2) and angiotensin-converting enzyme (ACE) may influence Q̇ (cardiac output). The 46G>A (G16R) SNP (single nucleotide polymorphism) has been associated with β2-mediated vasodilation, but the effect of ADRB2 haplotypes on Q̇ has not been studied. Five SNPs within ADRB2 (46G>A, 79C>G, 491C>T, 523C>A and 1053G>C by a pairwise tagging principle) and the I/D (insertion/deletion) polymorphism in ACE were genotyped in 143 subjects. Cardiovascular variables were evaluated by the Model flow method at rest and during incremental cycling exercise. Only the G16R polymorphism was associated with Q̇. In carriers of the Arg16 allele, Q̇rest (resting Q̇) was 0.4 [95% CI (confidence interval), 0.0–0.7] l/min lower than in G16G homozygotes (P=0.048). During exercise, the increase in Q̇ was by 4.7 (95% CI, 4.3–5.2) l/min per litre increase in pulmonary V̇O2 (oxygen uptake) in G16G subjects, but the increase was 0.5 (0.0–0.9) l/min lower in Arg16 carriers (P=0.035). A similar effect size was observed for the Arg16 haplotypes ACCCG and ACCCC. No interaction was found between ADRB2 and ACE polymorphisms. During exercise, the increase in Q̇ was 0.5 (CI, 0.0 –1.0) l/min greater in ACE I/I carriers compared with I/D and D/D subjects (P=0.054). In conclusion, the ADRB2 Arg16 allele in humans is associated with a lower Q̇ both at rest and during exercise, overriding the effects of haplotypes.

scholarly journals Effects of vagotomy on cardiovascular response to periodic apneas in sedated pigs

1999 ◽  
Vol 86 (6) ◽  
pp. 1890-1896 ◽  
Author(s):  
D. Slamowitz ◽  
L. Chen ◽  
S. M. Scharf
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Cardiovascular Response ◽  
Pressor Response ◽  
Mechanical Effects

There are few studies investigating the influence of vagally mediated reflexes on the cardiovascular response to apneas. In 12 sedated preinstrumented pigs, we studied the effects of vagotomy during apneas, controlling for apnea periodicity and thoracic mechanical effects. Nonobstructive apneas were produced by paralyzing and mechanically ventilating the animals, then turning the ventilator off and on every 30 s. Before vagotomy, relative to baseline, apnea caused increased mean arterial pressure (MAP; +19 ± 25%, P < 0.05), systemic vascular resistance (SVR; +33 ± 16%, P < 0.0005), and heart rate (HR; +5 ± 6%, P < 0.05) and decreased cardiac output (CO) and stroke volume (SV; −16 ± 10% P < 0.001). After vagotomy, no significant change occurred in MAP, SVR, and SV during apneas, but CO and HR increased relative to baseline. HR was always greater (∼14%, P < 0.01) during the interapneic interval compared with during apnea. We conclude that vagally mediated reflexes are important mediators of the apneic pressor response. HR increases after apnea termination are related, at least in part, to nonvagally mediated reflexes.

scholarly journals Developmental Changes in Hemodynamic Responses and Cardiovagal Modulation during Isometric Handgrip Exercise

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Styliani Goulopoulou ◽  
Bo Fernhall ◽  
Jill A. Kanaley
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Isometric Contraction ◽  
Pressor Response ◽  
Reflex Response ◽  
Group Differences ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise ◽  
Pressor Reflex

The purpose of this study was to examine differences in pressor response and cardiovagal modulation during isometric handgrip exercise (IHG) between children and adults. Beat-to-beat heart rate (HR) and blood pressure were measured in 23 prepubertal children and 23 adults at baseline and during IHG. Cardiovagal modulation was quantified by analysis of HR variability. Mean arterial pressure responses to IHG were greater in adults compared to children (P<.05) whereas there were no group differences in HR responses (P>.05). Children had a greater reduction in cardiovagal modulation in response to IHG compared to adults (P<.05). Changes in mean arterial pressure during IHG were correlated with baseline cardiovagal modulation and force produced during isometric contraction (P<.05). In conclusion, differences in pressor reflex response between children and adults cannot be solely explained by differences in autonomic modulation and appear to be associated with factors contributing to the force produced during isometric contraction.

scholarly journals Effect of β2-Adrenergic Receptor Polymorphism in Asthma Control of Patients Receiving Combination Treatment

2009 ◽  
Vol 50 (2) ◽  
pp. 182 ◽  
Author(s):  
Seung-Hyun Kim ◽  
Young-Min Ye ◽  
Gyu-Young Hur ◽  
Hyun-Young Lee ◽  
Young-Koo Jee ◽  
...  
Keyword(s):  
Asthma Control ◽  
Combination Treatment ◽  
Adrenergic Receptor ◽  
Β2 Adrenergic Receptor ◽  
Receptor Polymorphism

Sex differences in forebrain and cardiovagal responses at the onset of isometric handgrip exercise: a retrospective fMRI study

2007 ◽  
Vol 103 (4) ◽  
pp. 1402-1411 ◽  
Author(s):  
Savio W. Wong ◽  
Derek S. Kimmerly ◽  
Nicholas Massé ◽  
Ravi S. Menon ◽  
David F. Cechetto ◽  
...  
Keyword(s):  
Sex Differences ◽  
Maximal Voluntary Contraction ◽  
Cardiovascular Response ◽  
Isometric Exercise ◽  
Voluntary Contraction ◽  
Anterior Cingulate ◽  
Exercise Heart Rate ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Ventral Medial Prefrontal Cortex

In general, cardiac regulation is dominated by the sympathetic and parasympathetic nervous systems in men and women, respectively. Our recent study had revealed sex differences in the forebrain network associated with sympathoexcitatory response to baroreceptor unloading. The present study further examined the sex differences in forebrain modulation of cardiovagal response at the onset of isometric exercise. Forebrain activity in healthy men ( n = 8) and women ( n = 9) was measured using functional magnetic resonance imaging during 5 and 35% maximal voluntary contraction handgrip exercise. Heart rate (HR), mean arterial pressure (MAP), and muscle sympathetic nerve activity (MSNA) were collected in a separate recording session. During the exercise, HR and MAP increased progressively, while MSNA was suppressed ( P < 0.05). Relative to men, women demonstrated smaller HR (8 ± 2 vs. 18 ± 3 beats/min) and MAP (3 ± 2 vs. 11 ± 2 mmHg) responses to the 35% maximal voluntary contraction trials ( P < 0.05). Although a similar forebrain network was activated in both groups, the smaller cardiovascular response in women was reflected in a weaker insular cortex activation. Nevertheless, men did not show a stronger deactivation at the ventral medial prefrontal cortex, which has been associated with modulating cardiovagal activity. In contrast, the smaller cardiovascular response in women related to their stronger suppression of the dorsal anterior cingulate cortex activity, which has been associated with sympathetic control of the heart. Our findings revealed sex differences in both the physiological and forebrain responses to isometric exercise.

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