Donate Help Contact The AHA Sign In Home
American Heart Association
Hypertension
Search: search_blue_button Advanced Search
« Previous Article | Table of Contents | Next Article »
Hypertension. 2007;50:69-74
Published online before print May 21, 2007, doi: 10.1161/HYPERTENSIONAHA.107.088591
Free Article
This Article
Free upon publication Free Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Data Supplement
Right arrow All Versions of this Article:
50/1/69    most recent
HYPERTENSIONAHA.107.088591v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Li, D.
Right arrow Articles by Paterson, D. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Li, D.
Right arrow Articles by Paterson, D. J.
Related Collections
Right arrow Other hypertension
Right arrow Autonomic, reflex, and neurohumoral control of circulation
Right arrow Animal models of human disease

(Hypertension. 2007;50:69.)
© 2007 American Heart Association, Inc.

Original Articles

Noradrenergic Cell Specific Gene Transfer With Neuronal Nitric Oxide Synthase Reduces Cardiac Sympathetic Neurotransmission in Hypertensive Rats

Dan Li; Lijun Wang; Chee-Wan Lee; Tom A. Dawson; David J. Paterson

From the Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, Oxford, UK.

Correspondence to David J. Paterson DPhil, DSc, Department of Physiology, Anatomy, and Genetics, Sherrington Building, Parks Road, Oxford, UK OX1 3PT. E-mail david.paterson{at}physiol.ox.ac.uk


*    Abstract
up arrowTop
 *Abstract
down arrowIntroduction
 down arrowMaterials and Methods
 down arrowResults
 down arrowDiscussion
 down arrowReferences
 
Nitric oxide–cGMP pathway can inhibit cardiac norepinephrine (NE) release. Sympathetic hyper-responsiveness in hypertension may result from oxidative stress impairing this pathway. We tested the hypothesis that the gene transfer of neuronal NO synthase (nNOS) could restore sympathetic balance in the spontaneously hypertensive rat (SHR). An adenovirus (5x1010 particles) constructed with a noradrenergic neuron-specific promoter (PRS x8) encoding nNOS (Ad.PRS-nNOS) or enhanced green fluorescence protein (Ad.PRS-eGFP) was targeted to the right atrial wall by percutaneous injection in age-matched male SHRs and Wistar-Kyoto (WKY) rats. Five days after transduction, right atria were removed, and evoked [3H] norephinephrine (NE) release, NOS activity, and cGMP were measured. In the Ad.PRS-eGFP treated group, tissue levels of cGMP were significantly lower in the SHR compared with the WKY atria. NE release was also greater in the SHR, and soluble guanylate cyclase inhibition did not alter evoked [3H] NE release in the Ad.PRS-eGFP–treated SHR. All atria treated with Ad.PRS-nNOS had enhanced nNOS activity when compared with Ad.PRS-eGFP atria. Ad.PRS-nNOS in WKY rats reduced NE release compared with the Ad.PRS-eGFP group. Guanylate cyclase inhibition enhanced NE release in both Ad.PRS-nNOS– and Ad.PRS-eGFP–treated WKY atria. Ad.PRS-nNOS restored cGMP levels in the SHR to those seen in the WKY atria. In the SHR, Ad.PRS-nNOS also attenuated NE release compared with Ad.PRS-eGFP group. This was reversed by guanylate cyclase inhibition. We conclude that artificial upregulation of sympathetic nNOS via gene transfer with a noradrenergic promoter may provide a novel approach for correcting peripheral sympathetic hyperactivity in hypertension.


Key Words: nitric oxide • gene transfer • autonomic nervous system • norepinephrine • hypertension • cyclic GMP


*    Introduction
up arrowTop
 up arrowAbstract
 *Introduction
down arrowMaterials and Methods
 down arrowResults
 down arrowDiscussion
 down arrowReferences
 
In hypertension, cardiac autonomic impairment is an important contributor to the pathophysiological phenotype of the disease. Much evidence supports the observation that the activity of the sympathetic nervous system increases dramatically both in hypertensive patients1–4 and in the spontaneously hypertensive rat (SHR).5,6 The mechanism causing enhanced neurohumoral activation is unknown, but may be directly related to oxidative stress caused by hypertension disrupting nitric oxide (NO)–cGMP modulation of norepinephrine (NE) release in central autonomic nuclei7 and peripheral varicosities.8 Neuronal production of NO affects cardiac excitability through its action as a neuromodulator of postganglionic sympathovagal transmission.8–10 Both endogenous and exogenous NO inhibits evoked NE release during cardiac sympathetic nerve stimulation in the rat in vitro.11 Functionally, NO or the membrane-permeable cGMP analogue 8-bromo-cGMP decreases the heart rate response to sympathetic nerve stimulation in vitro, whereas NO synthase (NOS) inhibitors causes the opposite effect.12 In addition, oxidative stress caused by intermittent hypoxia decreases cardiac sympathetic neuronal NOS (nNOS) expression, which is associated with an enhanced heart rate response to sympathetic activation.13 Moreover, soluble guanylate cyclase (sGC), the key precursor of cGMP-dependent effects of NO, is downregulated in the aorta14 and the atria15 of the SHR. Tetrahydrobiopterin (BH4) and total biopterin levels are not different between SHR and Wistar-Kyoto (WKY) rat atria where sympathetic nerves innervate the heart, suggesting that BH4 is not uncoupled from NOS.15 Therefore strategies aimed at increasing bioavailability of NO could be advantageous in rescuing this impaired neural phenotype.

Gene transfer with adenoviral vectors is highly effective in modifying gene expression and has been used with good effect to understand whether changes in protein expression or enzyme activity play a key role in physiological function.16–18 Because adenoviruses transduce a broad range of cells, the gene of interest can be placed into cells that may not constitutively express them, thereby complicating the interpretation of the data. To minimize this limitation, we have recently developed a novel adenoviral vector constructed with a noradrenergic neuron-specific promoter (PRS x8) to drive nNOS or enhanced green fluorescence protein (eGFP) expression, and showed that nNOS targeted to only cardiac sympathetic neurons can inhibit noradrenergic neurotransmission and increase nNOS activity in normotensive rats.19

We therefore examined the hypothesis that a significant component of cardiac sympathetic hyper-responsiveness in hypertension occurs at the end organ level because of impaired NO-cyclic nucleotide signaling. From this we further hypothesized that gene transfer with a noradrenergic cell specific promoter coupled to nNOS could increase the bioactivity of nNOS and the production of cGMP that results in restoration of sympathetic transmission in the SHR to similar responses seen in the WKY rat.


*    Materials and Methods
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 *Materials and Methods
down arrowResults
 down arrowDiscussion
 down arrowReferences
 
An extended methods and results section can be found in the online data supplement available at http://hyper.ahajournals.org.

Animals
Age-matched (16 to 20 weeks old) male SHR (n=28) and WKY rats (n=28), young Sprague-Dawley (SD) rats (8 to 13 days old; n=6) were purchased from Harlan (Bicester, UK) and housed under standard laboratory conditions. The investigation conformed to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health (NIH Publication No. 85-23, revised 1996) and the Animals (Scientific Procedures) Act 1986 (UK) and were performed under British Home Office license requirements (PPL 30/2130).

Gene Transfer Procedure
Replication-deficient adenoviral vectors encoding recombinant eGFP or nNOS under control of the noradrenergic neuron-specific promoter (PRS x8) were generated as described previously.19 Targeted percutaneous gene transfer to the right atrium was performed under isoflurane (Isocare, Animalcare Ltd) anesthesia (4% for induction and 2% to 3% for maintenance, in 100% O2), using a technique similar to that described previously for the guinea pig.9 SHRs or WKY rats received an injection of 5x1010 particles of Ad.PRS-nNOS or Ad.PRS-eGFP in 300 µL of phosphate-buffered saline. Experiments were performed {approx}5 days after injection.

[3H]Norepinephrine Release Experiments on the Isolated Right Atrium
An isolated right atrium preparation was generated by the method described previously20 with some modification. Details and experimental protocols may be found in the online data supplement.

Immunohistochemistry
Cardiac sympathetic neuron isolation and transduction was prepared by the method described previously.19 Detailed methods for immunohistochemistry may be found in the online data supplement.

Measurement of Tissue cGMP Levels and NOS Activity
Details may be found in the online data supplement.

Solutions and Drugs
Rat Tyrode solution contained (in mmol/L): NaCl 120, KCl 4.7, MgSO4 1.2, KH2PO4 1.2, NaHCO3 25, CaCl2 2, and glucose 11. The solution was constantly aerated with carbogen to maintain pH at 7.4. All solutions were prepared fresh on the day of use using deionized water obtained from an Elga water purification system. Experiments using SNP were performed in a darkened room because of the light sensitivity of this drug.

Statistical Analysis
The results are given as the means±SEM. Analysis was performed using the paired or unpaired Student t test as appropriate. For all experiments, statistical significance was accepted at P<0.05.


*    Results
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 up arrowMaterials and Methods
 *Results
down arrowDiscussion
 down arrowReferences
 
Norepinephrine Release Was Increased in the SHR
Field stimulation-evoked release of [3H] NE from right atria was significantly enhanced at 5-Hz in the SHR (S1: +2.22±0.13%, S2: +2.19±0.14%, n=5) compared with the WKY rats (S1: +1.68±0.04%, S2: +1.55±0.04, n=6, P<0.01, unpaired t test; Figure 1). S1 and S2 represent the first and second field stimulation, respectively, where there was no difference between S1 and S2 in both strains indicating no significant time dependent changes.


Figure 1
View larger version (12K):
[in this window]
[in a new window]

  		Figure 1. A and B, Typical data trace showing measurement of [3H] NE release from isolated atria in response to 5-Hz field stimulation in WKY (A) and SHR (B). S1 and S2 represent the first and second stimulation. C, [3H] NE release was significantly increased at both stimulation in the SHR (n=5) compared with the WKY (n=6, **P<0.01, unpaired t test). Percentage changes in NE release was expressed as a ratio of increase in NE radioactivity after electrical stimulation over the total radioactivity.

Effects of SNP and ODQ on Release of Norepinephrine in Field Stimulation
To determine whether the sympathetic activated NO–cGMP pathway was impaired in the SHR, the exogenous NO donor SNP and the sGC inhibitor ODQ were applied to preparations. SNP (20 µmol/L) significantly decreased the release of [3H] NE in response to 5-Hz field stimulation in the WKY (from 1.63±0.09% to 1.28±0.10%, n=6, P<0.01, paired t test, Figure 2), whereas [3H] NE release from SHR atria (n=6) was unaffected by SNP. Conversely, ODQ (10 µmol/L) enhanced the release of [3H] NE in the WKY (from 1.60±0.07% to 1.82±0.11%, n=5, P<0.01, paired t test; Figure 3), but did not affect release in the SHR (n=6).


Figure 2
View larger version (16K):
[in this window]
[in a new window]

  		Figure 2. Effect of the NO donor SNP (20 µmol/L) on [3H] NE release during 5-Hz field stimulation in WKY and SHR. SNP significantly attenuated NE release from the WKY (n=6, {dagger}{dagger}P<0.01, paired t test) but not in the SHR (n=6; *P<0.05, **P<0.01, WKY vs SHR, unpaired t test).


Figure 3
View larger version (16K):
[in this window]
[in a new window]

  		Figure 3. Effect of sGC inhibitor ODQ (10 µmol/L) on [3H] NE release in response to 5-Hz field stimulation in WKY and SHR. ODQ significantly accelerate NE release from the WKY (n=5, {dagger}{dagger}P<0.01, paired t test), whereas release from SHR atria was unaffected (n=6; *P<0.05, WKY vs SHR, unpaired t test).

Sympathetic Neuron Specific Gene Transfer Mediated by Ad.PRS-nNOS
Majority of cultured sympathetic neurons did not have detectable amounts of endogenous nNOS. However, after 5 days after transduction with Ad.PRS-nNOS, nNOS was clearly detectable by nNOS antibody in 90% of sympathetic neurons (Figure 4A). nNOS expression in Ad.PRS-nNOS transduced cells colocalized with anti-TH stain (Figure 4B; scale bar, 50 µm).


Figure 4
View larger version (27K):
[in this window]
[in a new window]

  		Figure 4. Representative fluorescent images of cardiac sympathetic neurons after gene transfer with a noradrenergic neuron-specific vector Ad.PRS-nNOS. A, nNOS expression. B, Same cell preparation stained with sympathetic neuron marker anti-TH. C, Overlay of nNOS expression and anti-TH stain (Texas-red). Note that all nNOS-expressing neurons were colocalized with TH positive neurons. D, There was no detectable leakage of nNOS expression in other cell types because the other cells in the background stained with DAPI did not express nNOS. Scale bar, 50 µm for all images.

nNOS Activity After Ad.PRS-nNOS
We observed there was no difference in nNOS activity between SHR (n=9) and WKY (n=9) atria. After gene transfer with Ad.PRS-nNOS, nNOS activity was significantly enhanced in both strains compared with Ad.PRS-eGFP–treated atria (eg, SHR, increased from 14.6±2.3 to 20.5±3.1 fmol/mg/min, P<0.05; WKY, increased from 12.9±0.4 to 16.1±1.2 fmol/mg/min, P<0.05, n=6 in each group, Figure 5).


Figure 5
View larger version (16K):
[in this window]
[in a new window]

  		Figure 5. nNOS activity in atria was quantified by measuring the conversion of [3H]-L-arginine to [3H]-L-citrulline. Treated with Ad.PRS-nNOS was higher than Ad.PRS-eGFP group both in WKY and SHR (*P<0.05, unpaired t test, n=6 in each group).

Production of cGMP in Atria After Ad.PRS-nNOS
We observed cGMP concentration was significantly reduced in SHR compared with WKY tissue both in untreated tissue (3.57±0.11 versus 4.50±0.36 pmol/mg protein, P<0.05, unpaired t test, n=6 in each strain) and after gene transfer with Ad.PRS-eGFP (3.70±0.11 versus 4.37±0.17 pmol/mg protein, P<0.05, unpaired t test, n=6 in each strain; Figure 6). However, overexpression of Ad.PRS-nNOS reversed the attenuated production of cGMP in SHR (5.06±0.52 pmol/mg protein, n=6, P<0.05, unpaired t test) compared with untreated or Ad.PRS-eGFP–treated SHR.


Figure 6
View larger version (16K):
[in this window]
[in a new window]

  		Figure 6. Tissue levels of cGMP in SHR were significantly lower than that measured in WKY atria before or after gene-transferred Ad.PRS-eGFP ({dagger}P<0.05, unpaired t test). However, tissue cGMP were significantly increased after Ad.PRS-nNOS transfection in SHR (*P<0.05, unpaired t test; n=6 in each group).

Effects of Gene Transfer With Ad.PRS-nNOS on Release of Norepinephrine
Previously, we showed that the Ad.PRS-nNOS gene transfer significantly reduced norephinephrine release evoked by field stimulation of isolated right atria in the normotensive SD rat.19 In the present study, we observed similar results in the WKY rats (Figure 7A). Ad.PRS-nNOS (1.49±0.05%, n=6) caused 16.1±3.1% reduction in the evoked NE release compared with Ad.PRS-eGFP–treated tissue (1.77±0.02%, n=5, P<0.01, unpaired t test). sGC inhibitor ODQ (10 µmol/L) also significantly enhanced the sympathetic responsiveness in the WKY rats treated with either the Ad.PRS-nNOS (1.67±0.06%) or Ad.PRS-eGFP–treated tissue (2.09±0.08%) (P<0.01 respectively, unpaired t test). In the SHR (Figure 7B), overexpression of Ad.PRS-nNOS (1.59±0.08%, n=6) significantly decreased the [3H] NE release by 21.2±4.0% compared with Ad.PRS-eGFP (2.02±0.17%, n=5, P<0.05, unpaired t test). There was no effect of ODQ on Ad.PRS-eGFP–treated SHR atria. However, ODQ significantly increased the NE release from Ad.PRS-nNOS–transfected SHR atria (1.89±0.11%, n=6, P<0.05, paired t test).


Figure 7
View larger version (14K):
[in this window]
[in a new window]

  		Figure 7. Gene transferred with Ad.PRS-nNOS is significantly decreased [3H] NE release in WKY (A) and SHR (B) compared with Ad.PRS-eGFP, respectively (*P<0.05, **P<0.01, unpaired t test). This attenuation was reversed by ODQ in both transfected WKY and Ad.PRS-nNOS–treated SHR, but not in Ad.PRS-eGFP–treated SHR ({dagger}P<0.05, {dagger}{dagger}P<0.01, paired t test).


*    Discussion
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 up arrowMaterials and Methods
 up arrowResults
 *Discussion
down arrowReferences
 
In the present study, we report 3 novel findings. First, a significant component of the sympathetic hyper-responsiveness in the SHR occurs postganglionically at the end organ level with enhanced evoked norepinephrine release. Secondly, this response was associated with impaired sGC-cGMP signaling in the SHR compared with the WKY rat. Thirdly, targeted gene transfer of nNOS with a noradrenergic cell specific promoter increased the bioactivity of nNOS and cGMP levels in cardiac sympathetic nerves. This resulted in decreased NE release in the SHR to levels seen in the normotensive control.

Peripheral Sympathetic Activity in the SHR
Autonomic imbalance in the central and peripheral nervous system has been implicated in the etiology of hypertension, and is also seen after myocardial infarction and heart failure.21–24

Impaired cardiac parasympathetic regulation and enhanced sympathetic activity characterize cardiac disease states, and are regarded as an independent predictor of mortality.25,26 Bradycardia and acetylcholine release in response to vagal nerve stimulation is reduced in the SHR at the level of the cardiac postganglionic neurons.27 Here we observed that the norepinephrine release from right atria in response to field stimulation in the SHR was significantly higher compared with the WKY rat. This gives direct evidence that the sympathetic nervous system is hyper-reactive in the SHR at the level of heart, and is in general agreement with whole animal studies that report a global sympathetic phenotype in this model of hypertension.28,29

NO–cGMP Signaling in the SHR
Defective NOS signaling via eNOS has been widely implicated in the vascular aspect of hypertension, although cumulative evidence now suggests that neuronally synthesized NO may also play a role in the pathophysiology of hypertension.30 The signaling pathway responsible for nNOS-derived NO inhibiting sympathetic neurotransmission is not completely understood. However, it could involve NO modifying cell physiology through activation of sGC and subsequent induction of cGMP production, which in turn activates cGMP-dependent protein kinase and phosphodiesterases that decrease cAMP-dependent phosphorylation of neuronal Ca2+ channels resulting in decreased exocytosis of neurotransmitter.31

Emerging data indicates that sGC, the main target protein for NO, is markedly desensitized/downregulated in hypertension.14,32–35 In particular, downregulation of the {alpha}1 subunit of sGC in the atria and aorta of the SHR compared with WKY rat has recently been reported.15 We observed that guanylate cyclase inhibition increased NE release in the WKY but was without effect in the SHR, suggesting functional uncoupling of NO to its second messenger. Consistent with this idea we confirmed that tissue levels of cGMP were significantly lower in the SHR compared with the WKY. Translationally, decreased sGC expression and cGMP production has been proposed to account for impaired vasodilatation in the Afro-Caribbean population36 (susceptible to hypertension), fetal programming of hypertension,37 and in pulmonary hypertension.38 Similarly, downregulation of the sGC-dependent pathway34,35 has been demonstrated in aged and spontaneously hypertensive rats where superoxide production has been reported to trigger desensitization of vascular sGC in hypertension.34 Because nNOS activity and tetrahydrobiopterin levels in the SHR are not different compared with the WKY, this suggests uncoupling of nNOS from its main cofactor is unlikely to be the mechanism of peripheral sympathetic dysfunction in the SHR, and that the defect resides at the level of sGC-cGMP linkage.

Effect of Noradrenergic Neuron-Specific Overexpression of nNOS on Sympathetic Function in the SHR
Administration of the NO donor SNP did not decrease NE release in the SHR. It is possible that acute pharmacological administration of NO donors at a relatively low concentration (20 µmol/L) may not fully mimic the action of NO generated intracellularly by the nNOS transgene, given its labile and highly reactive properties. In particular, a relatively high local concentration of NO may be required to increase the bioavailability of NO under conditions of increased oxidative stress that have been demonstrated previously in hypertension.39,40 In addition, a much longer period of incubation may be need to achieve the effect than that can be provided in a stable in vitro experimental environment. However, overexpression of Ad.PRS-nNOS in the SHR significantly decreased the [3H] NE release compared with Ad.PRS-eGFP, and the sGC inhibitor ODQ significantly increased the NE release from Ad.PRS-nNOS–transduced SHR atria. The noradrenergic promoter is highly specific with no detectable leakage of gene expression into other cell types.19 Transduction with Ad.PRS-nNOS increased nNOS activity in the atrial extracts and enhanced atrial cGMP levels compared with Ad.PRS-eGFP. Importantly, gene transfer of adenovirus nNOS can also increase the expression of the defective {alpha}1 subunit of sGC in the SHR,27 which appears to be the key step for the functional changes. The mechanism underpinning this observation is not known, but when results are taken together they show that nNOS gene transfer provided a more potent NO signal than the NO donor.

Perspectives
Enhanced presynaptic postganglionic release of NE is not the only site of defective autonomic signaling in hypertension. nNOS gene transfer into the paraventricular nucleus can also decrease sympathetic outflow in the rat.41 In addition, our group15 recently found that the atria of the SHR were hyper-responsive to ß-adrenergic stimulation which was associated with elevated cAMP levels. This was accompanied by an increased basal and norepinephrine-stimulated L-type calcium current (ICaL) in single sinoatrial node cells. Gene transfer of nNOS decreased cAMP and the norepinephrine stimulated ICaL in the SHR. Combined with the present study, these results support the role of nNOS-sGC-cGMP in modulating peripheral noradrenergic activity at both presynaptic and postsynaptic levels, and that gene transfer of nNOS into either neurons or into pacemaking tissue can rescue the peripheral sympathetic hyperactivity seen in the SHR. Given the autocrine and paracrine action of NO in the heart, targeting both myocytes and sympathetic neurons with nNOS could be beneficial where this gaseous messenger may behave like a "smart beta blocker" that decreases overall adrenergic drive at these 2 sites. Whether this approach is viable to treat hyper-responsive sympathetic and beta adrenergic phenotypes remains to be established.


*    Acknowledgments
 
We thank Chris Hirst for his technical assistance for setting up the experimental apparatus.

Sources of Funding

This work was supported by a grant from the British Heart Foundation (to D.L., D.J.P.), the Medical Research Council (to L.W., D.J.P.), and the Wellcome Trust (to C.-W.L., D.J.P.).

Disclosures

None.

Received February 5, 2007; first decision February 26, 2007; accepted May 2, 2007.


*    References
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 up arrowMaterials and Methods
 up arrowResults
 up arrowDiscussion
 *References
 

  1. Sendeski MM, Consolim-Colombo FM, Leite CC, Rubira MC, Lessa P, Krieger EM. Increased sympathetic nerve activity correlates with neurovascular compression at the rostral ventrolateral medulla. Hypertension. 2006; 47: 988–995.[Abstract/Free Full Text]
  2. Huggett RJ, Burns J, Mackintosh AF, Mary DA. Sympathetic neural activation in nondiabetic metabolic syndrome and its further augmentation by hypertension. Hypertension. 2004; 44: 847–852.[Abstract/Free Full Text]
  3. Velez-Roa S, Ciarka A, Najem B, Vachiery JL, Naeije R, van de Borne P. Increased sympathetic nerve activity in pulmonary artery hypertension. Circulation. 2004; 110: 1308–1312.[Abstract/Free Full Text]
  4. Flaa A, Mundal HH, Eide I, Kjeldsen S, Rostrup M. Sympathetic activity and cardiovascular risk factors in young men in the low, normal, and high blood pressure ranges. Hypertension. 2006; 47: 396–402.[Abstract/Free Full Text]
  5. Fisher LD, Tucker DC. Air jet noise exposure rapidly increases blood pressure in young borderline hypertensive rats. J Hypertens. 1991; 9: 275–282.[CrossRef][Medline] [Order article via Infotrieve]
  6. Vonend O, Okonek A, Stegbauer J, Habbel S, Quack I, Rump LC. Renovascular effects of sympathetic cotransmitters ATP and NPY are age-dependent in spontaneously hypertensive rats. Cardiovasc Res. 2005; 66: 345–352.[Abstract/Free Full Text]
  7. Krukoff TL. Central regulation of autonomic function: no brakes? Clin Exp Pharmacol Physiol. 1998; 25: 474–478.[Medline] [Order article via Infotrieve]
  8. Danson EJ, Choate JK, Paterson DJ. Cardiac nitric oxide: emerging role for nNOS in regulating physiological function. Pharmacol Ther. 2005; 106: 57–74.[CrossRef][Medline] [Order article via Infotrieve]
  9. Mohan RM, Heaton DA, Danson EJF, Krishnan SPR, Cai S, Channon KM, Paterson DJ. Neuronal nitric oxide synthase gene transfer promotes cardiac vagal gain of function. Circ Res. 2002; 91: 1089–1091.[Abstract/Free Full Text]
  10. Wehling-Henricks M, Jordan MC, Roos KP, Deng B, Tidball JG. Cardiomyopathy in dystrophin-deficient hearts is prevented by expression of a neuronal nitric oxide synthase transgene in the myocardium. Hum Mol Genet. 2005; 14: 1921–1933.[Abstract/Free Full Text]
  11. Schwarz P, Diem R, Dun NJ, Forstermann U. Endogenous and exogenous nitric oxide inhibits norepinephrine release from rat heart sympathetic nerves. Circ Res. 1995; 77: 841–848.[Abstract/Free Full Text]
  12. Choate JK, Paterson DJ. Nitric oxide inhibits the positive chronotropic and inotropic responses to sympathetic nerve stimulation in the isolated guinea-pig atria. J Auton Nerv Syst. 1999; 75: 100–108.[CrossRef][Medline] [Order article via Infotrieve]
  13. Mohan RM, Golding S, Paterson DJ. Intermittent hypoxia modulates nNOS expression and heart rate response to sympathetic nerve stimulation. Am J Physiol Heart Circ Physiol. 2001; 281: H132–H138.[Abstract/Free Full Text]
  14. Ruetten H, Zabel U, Linz W, Schmidt HH. Downregulation of soluble guanylyl cyclase in young and aging spontaneously hypertensive rats. Circ Res. 1999; 85: 534–541.[Abstract/Free Full Text]
  15. Heaton DA, Lei M, Li D, Golding S, Dawson TA, Mohan RM, Paterson DJ. Remodeling of the cardiac pacemaker L-type calcium current and its beta-adrenergic responsiveness in hypertension after neuronal NO synthase gene transfer. Hypertension. 2006; 48: 443–452.[Abstract/Free Full Text]
  16. Isner JM. Myocardial gene therapy. Nature. 2002; 415: 234–239.[CrossRef][Medline] [Order article via Infotrieve]
  17. Channon KM, Blazing MA, Shetty GA, Potts KE, George SE. Adenoviral gene transfer of nitric oxide synthase: High level expression in human vascular cells. Cardiovasc Res. 1996; 32: 962–972.[CrossRef][Medline] [Order article via Infotrieve]
  18. Qian H, Neplioueva V, Shetty GA, Channon KM, George SE. Nitric oxide synthase gene therapy rapidly reduces adhesion molecule expression and inflammatory cell infiltration in carotid arteries of cholesterol-fed rabbits. Circulation. 1999; 99: 2979–2982.[Abstract/Free Full Text]
  19. Wang L, Li D, Plested CP, Dawson T, Teschemacher AG, Paterson DJ. Noradrenergic neuron-specific overexpression of nNOS in cardiac sympathetic nerves decreases neurotransmission. J Mol Cell Cardiol. 2006; 41: 364–370.[CrossRef][Medline] [Order article via Infotrieve]
  20. Oe K, Sperlagh B, Santha E, Matko I, Nagashima H, Foldes FF, Vizi ES. Modulation of norepinephrine release by ATP-dependent K(+)-channel activators and inhibitors in guinea-pig and human isolated right atrium. Cardiovasc Res. 1999; 43: 125–134.[Abstract/Free Full Text]
  21. Fujita M, Kuwaki T, Ando K, Fujita T. Sympatho-inhibitory action of endogenous adrenomedullin through inhibition of oxidative stress in the brain. Hypertension. 2005; 45: 1165–1172.[Abstract/Free Full Text]
  22. Cohn JN, Levine TB, Olivari MT, Garberg V, Lura D, Francis GS, Simon AB, Rector T. Plasma norepinephrine as a guide to prognosis in patients with chronic congestive heart failure. N Engl J Med. 1984; 311: 819–823.[Abstract]
  23. Kleiger RE, Miller JP, Bigger JT, Jr., Moss AJ. Decreased heart rate variability and its association with increased mortality after acute myocardial infarction. Am J Cardiol. 1987; 59: 256–262.[CrossRef][Medline] [Order article via Infotrieve]
  24. Zucker IH. Novel mechanisms of sympathetic regulation in chronic heart failure. Hypertension. 2006; 48: 1005–1011.[Free Full Text]
  25. La Rovere MT, Pinna GD, Hohnloser SH, Marcus FI, Mortara A, Nohara R, Bigger JT, Jr., Camm AJ, Schwartz PJ. Baroreflex sensitivity and heart rate variability in the identification of patients at risk for life-threatening arrhythmias: implications for clinical trials. Circulation. 2001; 103: 2072–2077.[Abstract/Free Full Text]
  26. Nishime EO, Cole CR, Blackstone EH, Pashkow FJ, Lauer MS. Heart rate recovery and treadmill exercise score as predictors of mortality in patients referred for exercise ECG. J Am Med Assoc. 2000; 284: 1392–1398.[Abstract/Free Full Text]
  27. Heaton DA, Li D, Almond SC, Dawson TA, Wang L, Channon KM, Paterson DJ. Gene Transfer of nNOS into Intracardiac Cholinergic Ganglia Reverses Vagal Impairment in Hypertensive Rats. Hypertension. 2007; 49: 380–388.[Abstract/Free Full Text]
  28. Cabassi A, Vinci S, Calzolari M, Bruschi G, Borghetti A. Regional sympathetic activity in pre-hypertensive phase of spontaneously hypertensive rats. Life Sci. 1998; 62: 1111–1118.[CrossRef][Medline] [Order article via Infotrieve]
  29. Huang BS, Leenen FH. Sympathoinhibitory effects of central nifedipine in spontaneously hypertensive rats on high versus regular sodium intake. Hypertension. 1999; 33: 32–35.[Abstract/Free Full Text]
  30. Chowdhary S, Townend JN. Nitric oxide and hypertension: not just an endothelium derived relaxing factor! J Hum Hypertens. 2001; 15: 219–227.[CrossRef][Medline] [Order article via Infotrieve]
  31. Paton JF, Kasparov S, Paterson DJ. Nitric oxide and autonomic control of heart rate: a question of specificity. Trends Neurosci. 2002; 25: 626–631.[CrossRef][Medline] [Order article via Infotrieve]
  32. Payne JA, Reckelhoff JF, Khalil RA. Role of oxidative stress in age-related reduction of NO–cGMP-mediated vascular relaxation in SHR. Am J Physiol Regul Integr Comp Physiol. 2003; 285: R542–R551.[Abstract/Free Full Text]
  33. Kagota S, Tamashiro A, Yamaguchi Y, Sugiura R, Kuno T, Nakamura K, Kunitomo M. Downregulation of vascular soluble guanylate cyclase induced by high salt intake in spontaneously hypertensive rats. Br J Pharmacol. 2001; 134: 737–744.[CrossRef][Medline] [Order article via Infotrieve]
  34. Kojda G, Kottenberg K, Hacker A, Noack E. Alterations of the vascular and the myocardial guanylate cyclase/cGMP-system induced by long-term hypertension in rats. Pharm Acta Helv. 1998; 73: 27–35.[CrossRef][Medline] [Order article via Infotrieve]
  35. Shirasaki Y, Kolm P, Nickols GA, Lee TJ. Endothelial regulation of cyclic GMP and vascular responses in hypertension. J Pharmacol Exp Ther. 1988; 245: 53–58.[Abstract/Free Full Text]
  36. Cardillo C, Kilcoyne CM, Cannon RO, 3rd, Panza JA. Attenuation of cyclic nucleotide-mediated smooth muscle relaxation in blacks as a cause of racial differences in vasodilator function. Circulation. 1999; 99: 90–95.[Abstract/Free Full Text]
  37. Lamireau D, Nuyt AM, Hou X, Bernier S, Beauchamp M, Gobeil F Jr., Lahaie I, Varma DR, Chemtob S. Altered vascular function in fetal programming of hypertension. Stroke. 2002; 33: 2992–2998.[Abstract/Free Full Text]
  38. Jiang Z, Lei Y, Gu K, Xianghua J, Liming X, Kejian H. The influences of NO and Ach on cGMP levels in two patient populations. J Extra Corpor Technol. 2001; 33: 23–26.[Medline] [Order article via Infotrieve]
  39. Hamilton CA, Brosnan MJ, McIntyre M, Graham D, Dominiczak AF. Superoxide excess in hypertension and aging: a common cause of endothelial dysfunction. Hypertension. 2001; 37: 529–534.[Abstract/Free Full Text]
  40. Kerr S, Brosnan MJ, McIntyre M, Reid JL, Dominiczak AF, Hamilton CA. Superoxide anion production is increased in a model of genetic hypertension: role of the endothelium. Hypertension. 1999; 33: 1353–1358.[Abstract/Free Full Text]
  41. Li YF, Roy SK, Channon KM, Zucker IH, Patel KP. Effect of in vivo gene transfer of nNOS in the PVN on renal nerve discharge in rats. Am J Physiol Heart Circ Physiol. 2002; 282: H594–H601.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. K. Choate, S. M. Murphy, R. Feldman, and C. R. Anderson
Sympathetic control of heart rate in nNOS knockout mice
Am J Physiol Heart Circ Physiol, January 1, 2008; 294(1): H354 - H361.
[Abstract] [Full Text] [PDF]

Home page
 CirculationHome page
N. Herring and D. J Paterson
Letter by Herring and Paterson Regarding Article, "Common NOS1AP Variants Are Associated With a Prolonged QTc Interval in the Rotterdam Study"
Circulation, December 11, 2007; 116(24): e564 - e564.
[Full Text] [PDF]

This Article
Free upon publication Free Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Data Supplement
Right arrow All Versions of this Article:
50/1/69    most recent
HYPERTENSIONAHA.107.088591v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Li, D.
Right arrow Articles by Paterson, D. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Li, D.
Right arrow Articles by Paterson, D. J.
Related Collections
Right arrow Other hypertension
Right arrow Autonomic, reflex, and neurohumoral control of circulation
Right arrow Animal models of human disease

Hypertension Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search
Copyright © 2007 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited.