Abstract 17082: Carotid Body Denervation Improves Autonomic Balance and Prevents the Worsening of Heart Failure in Rats After Large Myocardial Infarction

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Keita Saku ◽  
Takuya Kishi ◽  
Akiko Nishizaki ◽  
Kana Fujii ◽  
Takuya Akashi ◽  
...  

Introduction: Carotid body denervation (CBD) abolishes the carotid body hypersensitivity induced sympathoexcitatory hypertension. Since the carotid body hypersensitivity is a salient feature and predicts poor outcome of chronic heart failure (CHF), we hypothesized that CBD restores normal autonomic balance, thus improves CHF in rats after large myocardial infarction (MI). Methods: We created MI in 8 weeks Sprague-Dawley rats. Surviving rats at 2 weeks after MI were randomized into CBD (n=11) and sham-operated (Sham; n=13) groups. We removed the tissues around the carotid bifurcation and established CBD. In some rats (Sham; n=5, CBD; n=5), we telemetrically recorded heart rate (HR). One month after CBD, we compared physiological, histological and immunochemical findings between CBD and Sham. Results: CBD significantly reduced HR (337±15 vs. 364±12 bpm, p<0.05). CBD markedly increased the power spectral density of HR in the high frequency range (81.0±9.5 vs. 29.0±8.2 n.u., p<0.05) and decreased that of the low frequency/high frequency ratio (0.6±0.2 vs. 1.8±0.5, p<0.05) indicating the restoration of autonomic balance. CBD significantly reduced biventricular weight (3.1±0.3 vs. 3.7±0.3 g/kg, p<0.05) and left ventricle (LV) end-diastolic pressure (22±5 vs. 33±5 mmHg, p<0.01) and increased maximum LV dp/dt (5118±809 vs. 4217±472 mmHg/sec, p<0.05). CBD reduced lung weight (a marker of pulmonary edema) (6.8±2.0 vs. 12.4±1.5 g/kg, p<001). Furthermore, CBD reduced plasma brain natriuretic peptide (70±43 vs. 166±71 pg/ml, p<0.01) and plasma norepinephrine as an index of sympathetic drive (384±202 vs. 1048±997 pg/ml, p<0.05). CBD significantly reduced the number of inflammatory macrophages (345±45 vs. 474±73 counts/mm2, p<0.05) in the LV and the plasma concentration of interleukin-1β (14.3±4.7 vs. 24.5±11.8 pg/ml, p<0.05) indicating that CBD also suppressed the inflammatory response in CHF. Conclusions: CBD restores normal autonomic balance and prevents the worsening of heart failure in rats after large myocardial infarction. CBD may serve as a novel neuro-modulatory therapy for CHF patients.

2014 ◽  
Vol 20 (10) ◽  
pp. S182
Author(s):  
Keita Saku ◽  
Takuya Kishi ◽  
Akiko Nishizaki ◽  
Kana Fujii ◽  
Takuya Akashi ◽  
...  

2001 ◽  
Vol 281 (5) ◽  
pp. H2211-H2217 ◽  
Author(s):  
Per Ole Iversen ◽  
Gunnar Nicolaysen ◽  
Mouldy Sioud

Tumor necrosis factor-α (TNF-α) probably affects the pathogenesis of heart failure. Here we have investigated the therapeutic potential of a nuclease-resistant DNA enzyme that specifically cleaves TNF-α mRNA. A phosphorothioate-modified DNA enzyme was designed to retain similar cleavage activity as its unmodified version, and that inhibited the expression of TNF-α in vitro. To test its efficacy in vivo, postinfarction congestive heart failure was induced in anesthetized rats by ligation of the left coronary artery. A 4-wk treatment with the DNA enzyme induced a substantial reduction in left ventricular end-diastolic pressure and lung weight concomitant with an increase in arterial blood pressure and myocardial blood flow compared with controls. The concentration of TNF-α in coronary sinus blood was markedly lowered on treatment, and myocardial TNF-α mRNA was substantially reduced. Recovery studies showed that the DNA enzyme cleavage activity was present within the myocardium throughout the observation period and had no apparent toxic effects. Our findings indicate that DNA enzyme-based therapy may hold promise in the treatment of this debilitating disease.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shintaro Kinugawa ◽  
Shouji Matsushima ◽  
Takashi Yokota ◽  
Yukihiro Ohta ◽  
Naoki Inoue ◽  
...  

Type 2 diabetes mellitus (DM) adversely affects the outcomes in patients with myocardial infarction (MI), which is associated with the development of left ventricular (LV) remodeling and failure. NAD(P)H oxidase-derived superoxide (O 2 − ) production is increased in DM. However, its pathophysiological significance in advanced post-MI LV failure associated with DM remains unestablished. We thus determined whether an inhibitor of NAD(P)H oxidase activation, apocynin, could attenuate the exacerbated LV remodeling and heart failure after MI in high-fat diet (HFD)-induced obese mice with DM. Male C57BL/6J mice were fed on either HFD or normal diet (ND) for 8 weeks. At 4 weeks of feeding, MI was created in all mice by ligating left coronary artery. MI mice were treated with either apocynin (10 mmol/l in drinking water; n = 10 for ND and n = 11 for HFD) or vehicle (n = 15 for ND and n = 13 for HFD). HFD significantly increased body weight (BW), adipose tissue mass, fasting plasma glucose and insulin levels compared to ND after 4 and 8 weeks. HFD + MI had significantly greater LV end-diastolic diameter (LVEDD; 5.7 ± 0.1 vs. 5.3 ± 0.2 mm) by echocardiography, end-diastolic pressure (EDP; 12 ± 2 vs. 8 ± 1 mmHg) and lung weight/tibial length (10.1 ± 0.3 vs. 8.7 ± 0.7 mg/mm) than ND + MI, which was accompanied by an increased interstitial fibrosis of non-infarcted LV. Treatment of HFD + MI with apocynin significantly decreased LVEDD (5.4 ± 0.1 mm), LVEDP (9.7 ± 0.8 mmHg), lung weight/tibial length (9.0 ± 0.3 mg/mm), and concomitantly interstitial fibrosis of non-infarcted LV to ND + MI level without affecting BW, glucose metabolism, infarct size and aortic pressure. On the other hand, treatment of ND + MI with apocynin did not affect LV remodeling and failure. NAD(P)H oxidase activity, O 2 − production measured by lucigenin chemiluminescence, and thiobarbituric acid-reactive substances were increased in non-infarcted LV tissues from HFD + MI, all of which were also attenuated by apocynin to ND + MI level. Type 2 DM was associated with the exacerbation of LV remodeling and failure after MI via increasing NAD(P)H oxidase derived O 2 − production, which may be a novel important therapeutic target in advanced heart failure with DM.


2002 ◽  
Vol 282 (4) ◽  
pp. H1197-H1205 ◽  
Author(s):  
Michael J. Cox ◽  
Harpreet S. Sood ◽  
Matthew J. Hunt ◽  
Derrick Chandler ◽  
Jeffrey R. Henegar ◽  
...  

The hypothesis is that chronic increases in left ventricular (LV) load induce oxidative stress and latent matrix metalloproteinase (MMP) is activated, allowing the heart to dilate in the absence of endothelial nitric oxide (NO) and thereby reduce filling pressure. To create volume overload, an arteriovenous (A-V) fistula was placed in male Sprague-Dawley rats. To decrease oxidative stress and apoptosis, 0.08 mg/ml nicotinamide (Nic) was administered in drinking water 2 days before surgery. The rats were divided into the following groups: 1) A-V fistula, 2) A-V fistula + Nic, 3) sham operated, 4) sham + Nic, and 5) control (unoperated); n = 6 rats/group. After 4 wk, hemodynamic parameters were measured in anesthetized rats. The heart was removed and weighed, and LV tissue homogeneates were prepared. A-V fistula caused an increase in heart weight, lung weight, and end-diastolic pressure compared with the sham group. The levels of malondialdehyde (MDA; a marker of oxidative stress) was 6.60 ± 0.23 ng/mg protein and NO was 6.87 ± 1.21 nmol/l in the LV of A-V fistula rats by spectrophometry. Nic treatment increased NO to 13.88 ± 2.5 nmol/l and decreased MDA to 3.54 ± 0.34 ng/mg protein ( P= 0.005). Zymographic levels of MMP-2 were increased, as were protein levels of nitrotyrosine and collagen fragments by Western blot analysis. The inhibition of oxidative stress by Nic decreased nitrotyrosine content and MMP activity. The levels of tissue inhibitor of metalloproteinase-4 mRNA were decreased in A-V fistula rats and increased in A-V fistula rats treated with Nic by Northern blot analysis. TdT-mediated dUTP nick-end labeling-positive cells were increased in A-V fistula rats and decreased in fistula rats treated with Nic. Acetylcholine and nitroprusside responses in cardiac rings prepared from the above groups of rats suggest impaired endothelial-dependent cardiac relaxation. Treatment with Nic improves cardiac relaxation. The results suggest that an increase in the oxidative stress and generation of nitrotyrosine are, in part, responsible for the activation of metalloproteinase and decreased endocardial endothelial function in chronic LV volume overload.


2017 ◽  
Vol 30 (8) ◽  
pp. 791-798 ◽  
Author(s):  
Kana Fujii ◽  
Keita Saku ◽  
Takuya Kishi ◽  
Yasuhiro Oga ◽  
Takeshi Tohyama ◽  
...  

1994 ◽  
Vol 267 (1) ◽  
pp. H211-H216 ◽  
Author(s):  
K. Kiuchi ◽  
R. P. Shannon ◽  
N. Sato ◽  
M. Bigaud ◽  
C. Lajoie ◽  
...  

The development of heart failure (HF) on peripheral vascular control was studied in 10 conscious dogs with measurements of cardiac output (CO) and left ventricular (LV), arterial, and right atrial pressures. At 3 wk after pacing-induced HF, CO was not decreased from 2.5 +/- 0.2 l/min, whereas LV dP/dt fell (from 2,858 +/- 71 to 1,409 +/- 69 mmHg/s) and LV end-diastolic pressure increased (from 4.8 +/- 0.4 to 27.3 +/- 1.1 mmHg) (P < 0.05). At 4–7 wk after pacing, CO was significantly decreased (to 1.6 +/- 0.1 l/min; P < 0.05), but total peripheral resistance (TPR) did not rise, despite increases in plasma norepinephrine and renin activity (P < 0.05). In the presence of ganglionic blockade, TPR was still not increased in HF. In vitro studies in isolated femoral artery segments demonstrated reduced intrinsic tone (0.028 +/- 0.007 g/mg; P < 0.05) as compared with vessels from sham-operated controls (0.124 +/- 0.023 g/mg), whereas the intracellular calcium level was not altered in HF. Thus, during the development of HF, severe contractile dysfunction precedes the fall in CO, which, in turn, precedes the rise in TPR. The delayed rise in TPR appears to involve a reduction in intrinsic peripheral vascular tone, despite neurohumoral activation.


2001 ◽  
Vol 280 (3) ◽  
pp. H1129-H1135 ◽  
Author(s):  
Mohamed A. Gaballa ◽  
Andrea Eckhart ◽  
Walter J. Koch ◽  
Steven Goldman

We identified abnormalities in the vascular β-adrenergic receptor (β-AR) signaling pathway in heart failure after myocardial infarction (MI). To examine these abnormalities, we measured β-AR-mediated hemodynamics, vascular reactivity, and the vascular β-AR molecular signaling components in rats with heart failure after MI. Six weeks after MI, these rats had an increased left ventricular (LV) end-diastolic pressure, decreased LV systolic pressure, and decreased rate of LV pressure change (dP/d t). LV dP/d t responses to isoproterenol were shifted downward, although the responses for systemic vascular resistance were shifted upward in heart failure rats ( P < 0.05). Isoproterenol- and IBMX-induced vasorelaxations were blunted in heart failure rats ( P< 0.05) with no change in the forskolin-mediated vasorelaxation. These changes were associated with the following alterations in β-AR signaling ( P < 0.05): decreases in β-AR density (aorta: 58.7 ± 6.0 vs. 35.7 ± 1.9 fmol/mg membrane protein; carotid: 29.6 ± 5.6 vs. 18.0 ± 3.9 fmol/mg membrane protein, n = 5), increases in G protein-coupled receptor kinase activity levels (relative phosphorimage counts of 191 ± 39 vs. 259 ± 26 in the aorta and 115 ± 30 vs. 202 ± 7 in the carotid artery, n = 5), and decreases in cGMP and cAMP in the carotid artery (0.85 ± 0.10 vs. 0.31 ± 0.06 pmol/mg protein and 2.3 ± 0.3 vs. 1.2 ± 0.1 pmol/mg protein, n = 5) with no change in Gαs or Gαi in the aorta. Thus in heart failure there are abnormalities in the vascular β-AR system that are similar to those seen in the myocardium. This suggests a common neurohormonal mechanism and raises the possibility that treatment in heart failure focused on the myocardium may also affect the vasculature.


2015 ◽  
Vol 192 ◽  
pp. 16-17
Author(s):  
R. Del Rio ◽  
N.J. Marcus ◽  
D.C. Andrade ◽  
H.D. Schultz

2007 ◽  
Vol 13 (4) ◽  
pp. 209-214 ◽  
Author(s):  
Lisa M. Mielniczuk ◽  
Gervasio A. Lamas ◽  
Greg C. Flaker ◽  
Gary Mitchell ◽  
Sidney C. Smith ◽  
...  

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