Active renin and angiotensinogen in cardiac interstitial fluid after myocardial infarction

1999 ◽  
Vol 276 (6) ◽  
pp. H1818-H1826 ◽  
Author(s):  
Alan T. Hirsch ◽  
John A. Opsahl ◽  
Mary M. Lunzer ◽  
Stephen A. Katz
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Hypertrophy ◽  
Infarct Size ◽  
Interstitial Fluid ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Left Ventricular ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Active Renin

The renin-angiotensin system promotes cardiac hypertrophy after myocardial infarction. The purpose of this study was to measure renin and angiotensinogen in plasma and myocardium 10 days after myocardial infarction. Infarction involving 45 ± 4% of left ventricular circumference with accompanying hypertrophy was induced in rats ( n = 14). Plasma and myocardial renin were increased after infarction compared with sham controls ( n = 8) (27.4 ± 3.2 vs. 7.5 ± 1.8 ng ANG I ⋅ ml plasma ⋅ h−1, P < 0.0002; and 8.8 ± 1.6 vs. 2.5 ± 0.1 ng ANG I ⋅ g myocardium−1 ⋅ h−1, P < 0.008, respectively). After infarction, myocardial renin was correlated with infarct size ( r = 0.62, P < 0.02) and plasma renin ( r = 0.55, P < 0.04). Plasma angiotensinogen decreased in infarct animals, but myocardial angiotensinogen was not different from shams (1.1 ± 0.08 vs. 2.03 ± 0.06 nM/ml plasma, P < 0.002; and 0.081 ± 0.008 vs. 0.070 ± 0.004 nM/g myocardium, respectively). In conclusion, myocardial renin increased after infarction in proportion to plasma renin and infarct size, and myocardial angiotensinogen was maintained after infarction despite decreased plasma angiotensinogen and increased levels of myocardial renin.

Isoproterenol-induced cardiac hypertrophy: role of circulatory versus cardiac renin-angiotensin system

2001 ◽  
Vol 281 (6) ◽  
pp. H2410-H2416 ◽  
Author(s):  
Frans H. H. Leenen ◽  
Roselyn White ◽  
Baoxue Yuan
Keyword(s):  
Cardiac Hypertrophy ◽  
Enzyme Inhibitor ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Left Ventricular ◽  
Ang Ii ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Male Wistar Rats ◽  
Β Receptor

To assess the possible contribution of the circulatory and cardiac renin-angiotensin system (RAS) to the cardiac hypertrophy induced by a β-agonist, the present study evaluated the effects of isoproterenol, alone or combined with an angiotensin I-converting enzyme inhibitor or AT1 receptor blocker, on plasma and LV renin activity, ANG I, and ANG II, as well as left ventricular (LV) and right ventricular (RV) weight. Male Wistar rats received isoproterenol by osmotic minipump subcutaneously and quinapril or losartan once daily by gavage. Plasma and LV ANGs were measured by radioimmunoassay after separation by HPLC. Isoproterenol alone decreased blood pressure, more markedly when combined with losartan or quinapril. Isoproterenol significantly increased LV and RV weight and total collagen. Neither losartan nor quinapril inhibited the increases in LV or RV weight. Losartan prevented the increase in RV collagen but enhanced the increase in LV collagen. Isoproterenol increased plasma renin, ANG I, and ANG II three- to fourfold. Isoproterenol combined with losartan or quinapril, caused marked further increases except for a significant decrease in plasma ANG II with quinapril. Isoproterenol alone did not increase LV ANG II and, combined with losartan or quinapril, actually decreased LV ANG II. These results indicate that isoproterenol-induced cardiac hypertrophy is associated with clear increases in plasma ANG II, but not in LV ANG II. Both losartan and quinapril lower LV ANG II below control levels, but do not prevent the isoproterenol-induced cardiac hypertrophy. These findings do not support a role for the circulatory or cardiac RAS in the cardiac trophic responses to β-receptor stimulation.

scholarly journals Local renin-angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy

1999 ◽  
Vol 160 (1) ◽  
pp. 43-47 ◽  
Author(s):  
H Kobori ◽  
A Ichihara ◽  
Y Miyashita ◽  
M Hayashi ◽  
T Saruta
Keyword(s):  
Angiotensin Ii ◽  
Thyroid Hormone ◽  
Cardiac Hypertrophy ◽  
Plasma Renin Activity ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Plasma Angiotensin ◽  
Renin Mrna

We have reported previously that thyroid hormone activates the circulating and tissue renin-angiotensin systems without involving the sympathetic nervous system, which contributes to cardiac hypertrophy in hyperthyroidism. This study examined whether the circulating or tissue renin-angiotensin system plays the principal role in hyperthyroidism-induced cardiac hypertrophy. The circulating renin-angiotensin system in Sprague-Dawley rats was fixed by chronic angiotensin II infusion (40 ng/min, 28 days) via mini-osmotic pumps. Daily i.p. injection of thyroxine (0.1 mg/kg per day, 28 days) was used to mimic hyperthyroidism. Serum free tri-iodothyronine, plasma renin activity, plasma angiotensin II, cardiac renin and cardiac angiotensin II were measured with RIAs. The cardiac expression of renin mRNA was evaluated by semiquantitative reverse transcriptase-polymerase chain reaction. Plasma renin activity and plasma angiotensin II were kept constant in the angiotensin II and angiotensin II+thyroxine groups (0.12+/-0.03 and 0.15+/-0.03 microgram/h per liter, 126+/-5 and 130+/-5 ng/l respectively) (means+/-s.e.m.). Despite stabilization of the circulating renin-angiotensin system, thyroid hormone induced cardiac hypertrophy (5.0+/-0.5 vs 3.5+/-0.1 mg/g) in conjunction with the increases in cardiac expression of renin mRNA, cardiac renin and cardiac angiotensin II (74+/-2 vs 48+/-2%, 6.5+/-0.8 vs 3.8+/-0.4 ng/h per g, 231+/-30 vs 149+/-2 pg/g respectively). These results indicate that the local renin-angiotensin system plays the primary role in the development of hyperthyroidism-induced cardiac hypertrophy.

scholarly journals Transforming Growth Factor-β Blockade Down-Regulates the Renin-Angiotensin System and Modifies Cardiac Remodeling after Myocardial Infarction

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5828-5834 ◽  
Author(s):  
Leigh J. Ellmers ◽  
Nicola J. A. Scott ◽  
Satyanarayana Medicherla ◽  
Anna P. Pilbrow ◽  
Paul G. Bridgman ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Remodeling ◽  
Transforming Growth Factor ◽  
Ventricular Remodeling ◽  
Specific Inhibitor ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Type I ◽  
Angiotensin System ◽  
Renin Angiotensin

After myocardial infarction (MI), the heart may undergo progressive ventricular remodeling, resulting in a deterioration of cardiac function. TGF-β is a key cytokine that both initiates and terminates tissue repair, and its sustained production underlies the development of tissue fibrosis, particularly after MI. We investigated the effects of a novel orally active specific inhibitor of the TGF-β receptor 1 (SD-208) in an experimental model of MI. Mice underwent ligation of the left coronary artery to induce MI and were subsequently treated for 30 d after infarction with either SD-208 or a vehicle control. Blockade of TGF-β signaling reduced mean arterial pressure in all groups. SD-208 treatment after MI resulted in a trend for reduced ventricular and renal gene expression of TGF-β-activated kinase-1 (a downstream modulator of TGF-β signaling) and a significant decrease in collagen 1, in association with a marked decrease in cardiac mass. Post-MI SD-208 treatment significantly reduced circulating levels of plasma renin activity as well as down-regulating the components of the cardiac and renal renin-angiotensin system (angiotensinogen, angiotensin converting enzyme, and angiotensin II type I receptor). Our findings indicate that blockade of the TGF-β signaling pathway results in significant amelioration of deleterious cardiac remodeling after infarction.

Renin-angiotensin system involvement in pressure-overload cardiac hypertrophy in rats

1990 ◽  
Vol 259 (2) ◽  
pp. H324-H332 ◽  
Author(s):  
K. M. Baker ◽  
M. I. Chernin ◽  
S. K. Wixson ◽  
J. F. Aceto
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Abdominal Aorta ◽  
Pressure Overload ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
Angiotensin I ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Nuclease Mapping

We have recently shown that the octapeptide angiotensin II is a potent stimulus of protein synthesis and growth in cultured cardiomyocytes. The present study was performed to determine if the renin-angiotensin system was involved in regulating cardiac cell growth in vivo. The pressure-overload cardiac hypertrophy model that develops in abdominal aorta-constricted rats was studied. At 7 and 15 days after abdominal aorta constriction, rats developed significant left ventricular hypertrophy. The increase in left ventricular mass was completely prevented in animals fed the angiotensin-converting enzyme inhibitor, enalapril maleate (0.2 mg/ml) in their drinking water. Cardiac afterload was the same in both groups of animals in that carotid artery pressures were not different in conscious awake aortic-constricted animals receiving and not receiving enalapril. These data suggest a direct growth effect of angiotensin II on the left ventricle and indicate a role for the renin-angiotensin system in the cardiac hypertrophy that develops in response to pressure overload. The presence and chamber localization of angiotensinogen mRNA was determined using Northern hybridization and S1 nuclease mapping analysis. Angiotensinogen mRNA, as determined by dot-blot hybridization analysis, was significantly increased in hypertrophied left ventricles at both 7 and 15 days after the surgery, when compared with sham-operated controls. The activity of the circulating renin-angiotensin system, as indexed by plasma renin activity was increased at 1 day following surgery [6.0 +/- 2.0 ng.ml-1.h-1 angiotensin I (control) vs. 41.8 +/- 10.9 ng.ml-1.h-1 angiotensin I (experimental)], but returned to control values by day 3 postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Role of renin-angiotensin system in development of heart failure induced by myocardial infarction in rats

2007 ◽  
Vol 79 (2) ◽  
pp. 250-259 ◽  
Author(s):  
Daniel C. Trindade ◽  
Raquel C. Trindade ◽  
Michelle P. Marassi ◽  
Ornélia P.P.R. Martins ◽  
Ricardo H. Costa-e-Sousa ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
P Wave ◽  
Coronary Artery Ligation ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Functional Changes ◽  
Rat Hearts

We investigated the morphologic and functional changes of infarcted rat hearts under a paradigm of angiotensinconverting enzyme inhibition. Myocardial infarction was induced by left coronary artery ligation and a control group (SHAM) underwent sham-operation. Infarcted rats received normal drinking water with (CAP group) or without (INF group) captopril. Functional assessment was performed by electro (ECG) and echocardiogram (ECHO) just before and 21 days after surgery. The ECG of INF and CAP showed similar values and resembled healed infarct after surgery. The most outstanding differences between INF and CAP were the prevention of the increase of P-wave and attenuation both in rightward deviation of the QRS axis and Q-wave amplitude in CAP compared with INF. The ECHO showed that captopril treatment improved the diastolic filling more than systolic performance. Cardiac dilatation and left congestive heart failure were observed only in INF. Both infarcted groups showed a scar tissue in the left ventricular wall, but the INF showed a higher scar area than CAP (49.7 ± 5.24 vs. 22.33 ± 6.19 respectively). These data suggest that the renin-angiotensin system induces morphologic and functional changes in post-infarcted rat hearts and which can be assessed by non-invasive exams.

Pressure-overload hypertrophy is unabated in mice devoid of AT1A receptors

1998 ◽  
Vol 274 (3) ◽  
pp. H868-H873 ◽  
Author(s):  
Masayoshi Hamawaki ◽  
Thomas M. Coffman ◽  
Andrew Lashus ◽  
Masaaki Koide ◽  
Michael R. Zile ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Knockout Mice ◽  
Weight Ratio ◽  
Pressure Overload ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
Wild Type ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Hypertrophic Response

Mechanisms controlling cardiac growth are under intense investigation. Among these, the renin-angiotensin system has received great interest. In the current study, we tested the hypothesis that the renin-angiotensin system was not an obligate factor in cardiac hypertrophy. We examined the left ventricular hypertrophic response to a pressure overload in mice devoid of the AT1A receptor, the putative major effector of the growth response of the renin-angiotensin system. Aortic banding produced similar transband gradients in wild-type and AT1A knockout mice. The left ventricular mass-to-body weight ratio increased from 3.44 ± 0.08 to 5.62 ± 0.25 in wild-type ascending aortic-banded mice. The response in the knockout mice was not different (from 2.97 ± 0.13 to 5.24 ± 0.37). We conclude that the magnitude of cardiac hypertrophy is not affected by the absence of the AT1A receptor and its signaling pathway and that this component of the renin-angiotensin system is not necessary in cardiac hypertrophy.

P4473Brain renin-angiotensin system blockade with firibastat, an orally active, central acting aminopeptidase A inhibitor prodrug prevents cardiac dysfunction after myocardial infarction in mice

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Boitard-Joanne ◽  
Y Marc ◽  
M Keck ◽  
N Mougenot ◽  
O Agbulut ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Dysfunction ◽  
Enzyme Inhibitor ◽  
Diastolic Pressure ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
Mrna Levels ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Aminopeptidase A

Abstract Introduction Brain renin-angiotensin system (RAS) hyperactivity has been implicated in sympathetic hyperactivity and progressive left ventricular (LV) dysfunction after myocardial infarction (MI). Brain angiotensin III, generated by aminopeptidase A (APA), is one of the main effector peptides of the brain RAS in the control of cardiac function. Purpose We hypothesized that orally administered firibastat (previously named RB150), an orally central acting APA inhibitor prodrug, would attenuate heart failure (HF) development after MI in mice, by blocking brain RAS hyperactivity. Methods Two days after MI induced by the left anterior descending artery ligation, adult male CD1 mice were randomized to three groups, for four to eight weeks of oral treatment with vehicle (MI+vehicle), firibastat (150 mg/kg; MI+firibastat) or the angiotensin I converting enzyme inhibitor enalapril (1 mg/kg; MI+enalapril) as a positive control. Results From one to four weeks post-MI, brain APA hyperactivity occurred, contributing to brain RAS hyperactivity. Firibastat treatment during four weeks after MI normalized brain APA hyperactivity, with a return to the control values measured in the sham group. Four and six weeks after MI, MI+firibastat mice had a significant lower LV end-diastolic pressure, LV end-systolic diameter and volume, and a higher LV ejection fraction than MI+vehicle mice. Moreover, the mRNA levels of biomarkers of HF (Myh7, Bnp and Anf) were significantly lower following firibastat treatment. For a similar infarct size, the peri-infarct area of MI+firibastat mice displayed lower levels of mRNA for markers of fibrosis such Ctgf and collagen types I and III than MI+vehicle mice. Conclusions Chronic oral firibastat administration after MI in mice normalizes brain APA hyperactivity, thereby normalizing brain RAS hyperactivity, whilst preventing cardiac dysfunction and attenuating cardiac hypertrophy and fibrosis. Acknowledgement/Funding INSERM, College de France, ANR LabCom, and Quantum Genomics

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