scholarly journals Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice

Author(s):  
Shuxun Ren ◽  
Sunny Chang ◽  
Alex Tran ◽  
Arianna Mandelli ◽  
Yibin Wang ◽  
...  
Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Tiankai Li ◽  
Heng-Jie Cheng ◽  
Shadi A Qasem ◽  
Michael Callahan ◽  
Wei-Min Li ◽  
...  

Background: We have shown that Sildenafil (SIL), a selective PDE5 inhibitor reversed left ventricular (LV) dysfunction and β- adrenergic receptors (AR) desensitization in heart failure (HF). However the mechanism is not yet clear. Recent evidence suggests that normal myocardial performance depend on the balance in cardiomyocyte β 3 -, β 1 -, and β 2 -AR. Pivotal restructuring of β-AR system resulting in decline of β-adrenergic reserve plays a crucial role in the development of HF. We assessed the hypothesis that chronic SIL would prevent HF-induced abnormalities of β-AR subtype-stimulated regulation on intrinsic LV myocyte function and [Ca 2+ ] i regulation, thus restoring cardiac function. Methods: Studies were conducted in 3 groups (10/group) of rats: 1) HF, 12 weeks (W) after receiving isoproterenol (ISO) (170 mg/kg sq for 2 days); 2) HF/SIL, 8W after receiving ISO, SIL (70 μg/kg/day sq via mini pump) was initiated and given for 1 M; and 3) controls. After 12W, we compared LV myocyte contractile and [Ca 2+ ] iT responses to β-AR subtype stimulation by random exposure of myocytes to ISO (10 -8 M) or a selective β 1 -, β 2 -, or β 3 -agonist, Norepinephrine (NE, 10 -7 M), Zinterol (ZIN, 10 -5 M) and BRL-37,344 (BRL, 10 -8 M), respectively, during drug superfusion. Results: Only ISO-treated rats had HF showed 46% decreased LV contractility (E ES ) and extensive LV myocardium fibrosis. Compared with normal myocytes (N), in HF myocytes, basal cell contractility (dL/dt max , HF: 77 vs N: 136 μm/s), relaxation and [Ca 2+ ] iT all significantly decreased. ISO-stimulated dL/dt max (31% vs 67%) was attenuated accompanied by a diminished NE-mediated increase in dL/dt max (13% vs 49%), but enhanced BRL-induced decreases in dL/dt max (-29% vs -16%).The response of dL/dt max (25% vs 15%) to ZIN was increased. Importantly, in HF/SIL myocytes, the basal dL/dt max (139 μm/s) and [Ca 2+ ] iT remained close to control values with preserved β-stimulated positive modulation on cell contraction. The increases in dL/dt max in response to ISO (70%) and NE (44%) were similar as in normal myocytes, but repose to ZIN (27%) was enhanced. Conclusions: Chronic SIL reverses β-adrenergic signaling defects, resensitizing the β-AR subtype system modulation on LV myocytes function, thus playing a salutary role in HF.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Yao Wu ◽  
Feifei Si ◽  
Xiaojuan Ji ◽  
Kunfeng Jiang ◽  
Sijie Song ◽  
...  

Background. This study was undertaken to determine relative contributions of phosphorylation and oxidation to the increased activity of calcium/calmodulin-stimulated protein kinase II (CaMKII) in juveniles with cardiac myocyte dysfunction due to increased pressure overload. Methods. Juvenile rats underwent abdominal aortic constriction to induce heart failure. Four weeks after surgery, rats were then randomly divided into two groups: one group given valsartan (HF + Val) and the other group given placebo (HF + PBO). Simultaneously, the sham-operated rats were randomly given valsartan (Sham + Val) or placebo (Sham + PBO). After 4 weeks of treatment, Western blot analysis was employed to quantify CaMKII and relative calcium handling proteins (RyR2 and PLN) in all groups. Results. The deteriorated cardiac function was reversed by valsartan treatment. In ventricular muscle cells of group HF + PBO, Thr287 phosphorylation of CaMKII and S2808 phosphorylation of RyR2 and PLN were increased and S16 phosphorylation of PLN was decreased compared to the other groups, while Met281 oxidation was not significantly elevated. In addition, these changes in the expression of calcium handling proteins were ameliorated by valsartan administration. Conclusions. The phosphorylation of Thr286 is associated with the early activation of CaMKII rather than the oxidation of Met281.


Author(s):  
L. Hay ◽  
R.A. Schultz ◽  
P.J. Schutte

Previous studies have shown that crude extracts from Pavetta harborii as well as dried plant material have cardiotoxic effects on rats and sheep that can lead to heart failure. The active component has since been isolated and identified. This substance has been named pavetamine. The aim of this study was to determine whether pavetamine has cardiotoxic effects similar to those seen in previous reports, when administered to rats intraperitoneally. Sprague Dawley rats received two doses, initially 4 mg / kg and then 3 mg / kg pavetamine respectively and were monitored for 35 days before cardiodynamic parameters were measured by inserting a fluid-filled catheter into the left ventricle via the right carotid artery. These values were compared to those of control rats that had received only saline. Pavetamine significantly reduced systolic function and body mass in the treated rats, which indicates that it has the potential to induce heart failure in this animal model.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Xiaoqiang Sun ◽  
Che Cheng ◽  
Jing Cao ◽  
Zhi Zhang ◽  
Tiankai Li ◽  
...  

Background: The negative inotrope and up-regulation of β 3 -adrenergic receptors (AR) in human and animal failing hearts suggest a direct and contributing role of cardiac β 3 -AR activation on the progression of congestive heart failure (CHF). However, its precise role is still being debated. We hypothesize that up-regulation of cardiac β 3 -AR is detrimental and chronic β 3 -AR blockade may prevent CHF-caused intrinsic defects of left ventricular (LV) myocyte force-generating capacity and relaxation and improve β-AR regulation, thereby limiting the progression of CHF. Methods: We compared the alterations of LV and myocyte functional responses and [Ca 2+ ] i transient ([Ca 2+ ] iT ) in SD rats divided into 3 groups (8/group): 1) CHF 3 months after isoproterenol (ISO) (170 mg/kg, sq, for 2 days); 2) ISO/β 3 -ANT , 2 months after receiving ISO, a selective β 3 -AR antagonist (ANT), L-748,337, was initiated (10 -7 M/kg/day, sq. by mini-pump) and was given for 1 month; and 3) Sham controls . Results: Compared with controls, the animals that received ISO treatment had CHF onset at 1 month and progressed to severe HF at 3 months after ISO. Plasma norepinephrine (NE) (1295 vs 259 pg/ml) increased 5-fold; whereas, stroke volume (SV) (39 vs 91 μl) and ejection fraction (EF) (39 vs 62%) significantly decreased, and LV end-diastolic pressure (P ED ) (13.9 vs 6.0 mmHg) was doubled. These changes were paralleled with about 50% reductions in cell contraction (dL/dt max , 93 vs 186 μm/s) and relaxation (dR/dt max , 96 vs 159 μm/s) associated with a significant decrease in the peak systolic [Ca 2+ ] iT , (0.17 vs 0.26). In addition, superfusion of ISO (10 -8 M) caused much less increases in dL/dt max (39 vs 68%), dR/dt max (23 vs 54%), and [Ca 2+ ] IT (14 vs 28%). Treatment with β 3 -ANT increased SV (89 μl) and EF (60%), decreased P ED more than 90% from ISO-treated values, and corrected the elevation of plasma NE (301 pg/ml), dL/dt max (184 μm/s), dR/dt max (152 μm/s), and [Ca 2+ ] iT (0.24). ISO-induced increase in dL/dt max and [Ca 2+ ] iT also returned close to control levels. Conclusion: Chronic β 3 -ANT treatment after CHF significantly improves LV and myocyte contractile function and [Ca 2+ ] i regulation and limits the development of CHF. Thus, β 3 -AR blocker may provide a new therapeutic strategy for the treatment of CHF.


2009 ◽  
Vol 57 (08) ◽  
pp. 441-448 ◽  
Author(s):  
H. Möllmann ◽  
S. Voss ◽  
H. Nef ◽  
M. Lintz ◽  
C. Oltenau ◽  
...  

Author(s):  
Fatima Alkawari ◽  
Wigdan Ali ◽  
Fatiha Benslimane ◽  
Huseyin Yalcin

Type 2 diabetes mellitus (T2DM) affects >16% of adults in Qatar. Newly emerging class of antidiabetic drugs focused on SGLT inhibition were observed to reduce CVDs risks in diabetic patients. Up to date, the mechanism contributing to the CV benefits remains unrevealed. Zebrafish embryos were treated with Aristolochic Acid to induce heart failure then treated with Empagliflozin to determine its beneficial effect. Furthermore the expression of SGLT1 & 2 were determined in the hearts of zebrafish. SGLT2 was expressed more then SGLT1 in the heart and whole embryo. Empa significantly improved the zebrafish embryo'scardiachealthafterinductionofheartfailure.


2021 ◽  
Vol 71 (3) ◽  
pp. 473-484
Author(s):  
Chun Yu ◽  
Donghao Li ◽  
Zhongyan Li ◽  
Donghui Yu ◽  
Guijuan Zhai

AbstractOur study evaluates the effects of sacubitril/valsartan (SAC/VAL) in the rabbit model of doxorubicin-induced heart failure. Twenty rabbits (5 per group) were administered with doxorubicin (DOX, 1.5 mg kg−1, i.v.) to induce heart failure. Specific biomarkers such as BNP, CnT, CRP and ROMs were determined. The cardiac enzymatic anti-oxidant systems were recorded with their electrographic profiles. HR, SBP, DBP and MAP were restored at 5 or 10 mg kg−1 (p.o.) of SAC/VAL compared to DOX, followed by reduced levels of creatinine and BNP (p < 0.001). Significant improvements (p < 0.05) compared to DOX were also noticed in CAT, SOD and LPO with the same doses of SAC/VAL. Specific biomarkers such as BNP, CnT, CRP and ROMs descended significantly (p < 0.001) with treatment when compared to their baseline values. Our findings implied that SAC/VAL treatment reduced the inflammation and oxidative stress to improve the cardiac function.


2005 ◽  
Vol 99 (4) ◽  
pp. 1428-1433 ◽  
Author(s):  
James A. Kuzman ◽  
Tracy A. Thomas ◽  
Kathryn A. Vogelsang ◽  
Suleman Said ◽  
Brent E. Anderson ◽  
...  

Thyroid hormones (TH) enhance cardiac function and reverse gene changes typical of pathological hypertrophy. However, reports in humans, but not animals, indicate that excess TH can cause heart failure. Also, the effects of TH on normal and cardiomyopathic hearts are likely to be different. The goal of this study was to characterize the effects of prolonged hyperthyroidism on cardiac function, chamber and cellular remodeling, and protein expression in both normal and cardiomyopathic hearts. Hyperthyroidism was induced in 3-mo-old normal BIO F1B and dilated cardiomyopathic BIO TO2 hamsters. After TH treatment for 10 days and 2 mo, hemodynamics, echos, myocyte length, histology, and protein expression were assessed. After 10 days and 2 mo, there were no differences between TO2-treated (Tx) and TO2-untreated (Untx) hamsters in chamber diameters or left ventricular function. After 2 mo of treatment, however, F1B-Tx showed evidence of dilated heart failure vs. F1B-Untx. Chamber diameters were increased, and ejection fraction and positive and negative changes in pressure over time were reduced. In F1B-Tx and TO2-Tx hamsters, β-myosin isoform expression was reduced, whereas α-myosin increased significantly in F1B-Tx only. In TO2-Tx hamsters, the percent of viable myocardium was increased, and percent fibronecrosis was reduced vs. TO2-Untx. Myocyte length increased with TH treatment in both hamster strains. We conclude that 1) excess TH can induce heart failure in normal animals as observed in humans, 2) reversal of myosin heavy chain expression does not necessarily improve heart function, and 3) excess TH altered cellular remodeling but did not adversely affect chamber function or dimensions in TO2 hamsters.


1986 ◽  
Vol 251 (2) ◽  
pp. H227-H235 ◽  
Author(s):  
J. R. Wilson ◽  
R. Falcone ◽  
N. Ferraro ◽  
J. Egler

To investigate the mechanism responsible for underperfusion of working skeletal muscle in heart failure, we measured systemic and femoral bed hemodynamics during treadmill exercise and gracilis muscle resistance during contraction frequencies of 1-9 Hz in 8 dogs ventricularly paced at 260 beats/min for 3 wk to induce heart failure (HF) and in 9 control dogs. At peak treadmill exercise (4 mph, 10%), HF dogs had reduced cardiac outputs (control: 297 +/- 42 vs. HF: 212 +/- 16 ml X min-1 X kg-1) and femoral bed flows (control: 352 +/- 112 vs. HF: 229 +/- 95 ml/min) and elevated arterial lactates [control: 1.7 +/- 0.7 vs. HF: 4.1 +/- 0.7 mM (all P less than 0.04)], consistent with skeletal muscle underperfusion. This muscle underperfusion was associated with reduced mean arteriovenous pressure gradients [control: 119 +/- 12 vs. HF: 91 +/- 9 mmHg (P less than 0.001)] but with normal systemic vascular [control: 21 +/- 6 vs. HF: 23 +/- 5 U (P = NS)] and femoral bed resistances [control: 3.5 +/- 1.6 vs. HF: 4.4 +/- 2.3 X 10(2) U (P = NS)]. Both groups also had similar gracilis muscle minimal resistance during exercise (control: 2.0 +/- 1.1 vs. HF: 1.9 +/- 0.9 X 10(3) U/100 g) and following maximal vasodilation (control: 2.0 +/- 1.0 vs. HF: 2.1 +/- 1.0 X 10(3) U/100 g). These results suggest that 1) short-term rapid ventricular pacing in the dog produces a model of low output HF resembling HF in humans, and 2) skeletal muscle underperfusion in this model is due to a reduced muscle arteriovenous pressure gradient and not to impaired skeletal muscle arteriolar vasodilation.


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