Low extracellular Ca2+ and enzyme release in the perfused rabbit heart

1984 ◽  
Vol 62 (9) ◽  
pp. 1158-1165 ◽  
Author(s):  
Pierre A. Fortier ◽  
Gary K. Bedford ◽  
Miguel A. Chiong
Keyword(s):  
Creatine Kinase ◽  
Systolic Pressure ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Control Group ◽  
Enzyme Release ◽  
Ventricular Systolic Pressure ◽  
Coronary Sinus Flow ◽  
Perfused Rabbit Heart ◽  
Cardiac Functions

Previous studies have shown that the well-oxygenated perfused rabbit heart releases creatine kinase when treated with the calcium antagonist drug verapamil (VER) in a dose-related manner. It is possible that this effect is related to Ca2+ ion deprivation of the sarcolemma. This possibility was explored by perfusing hearts with low Ca2+ (0.5, 0.23, 0.15, and 0 mM) versus a control group (1.27 mM Ca2+) for 60 min. Low Ca2+ perfusion was associated with (i) reduction in the heart rate – left ventricular systolic pressure product and O2 consumption, (ii) tendency for the coronary sinus flow to increase, (iii) electromechanical dissociation, prolongation of atrioventricular conduction and QT interval, and (iv) decrease in myocardial glycogen. Lower total adenosine nucleotides were found only in the 0 mM Ca2+ group. As the Ca2+ concentration was reduced, the hearts lost increasing amounts of creatine kinase, aspartate aminotransferase, and lactate dehydrogenase. These results confirm the importance of Ca2+ ions in contractile and electrical cardiac functions and show that decreased availability of this cation leads to increasing enzyme leakage resembling that seen in VER-treated hearts.

Metabolism of the isolated perfused rabbit heart. III. Energy stores and creatine kinase release during prolonged reoxygenation and atrial pacing

1979 ◽  
Vol 57 (10) ◽  
pp. 1058-1066 ◽  
Author(s):  
Miguel A. Chiong ◽  
Timothy L. Winton
Keyword(s):  
Creatine Kinase ◽  
Mechanical Performance ◽  
Recovery Period ◽  
Systolic Pressure ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Atrial Pacing ◽  
Myocardial Uptake ◽  
Ventricular Systolic Pressure ◽  
Perfused Rabbit Heart

When the perfused rabbit heart is reoxygenated for 75 min after 25 min of anoxic perfusion, left ventricle performance stabilizes at 50% of control levels, but the rate of creatine kinase (CK) release is high (1.9 U/min) and ATP stores are low (5 μmol/g dry weight). These results suggest that the preparation is on the verge of severe failure. This possibility was investigated by following the recovery for an extra 60 min of reoxygenation and by stressing the hearts with atrial pacing.The data show that no deterioration occurred during the extra recovery period; on the contrary, mechanical performance remained stable, while the rate of CK release fell to 1.1 U/min, and ATP stores increased by 204%. In aerobic hearts, pacing increased the product of left ventricular systolic pressure (LVSP) and heart rate, myocardial uptake of oxygen [Formula: see text], coronary sinus flow, and O2 extraction, but LVSP and [Formula: see text] per beat fell. Similar responses were seen in postanoxic hearts, but LVSP improved during pacing while the rate of CK loss declined and ATP stores increased. These metabolic changes were inversely related to the rate of contraction. It is concluded that the preparation was not deteriorating at 75 min of reoxygenation, and that its metabolism was improved by cardiac pacing.

Metabolism of the perfused rabbit heart. IV. Effects of β-adrenergic blockade on enzyme release and late energy stores during postanoxic reoxygenation

1980 ◽  
Vol 58 (5) ◽  
pp. 469-476 ◽  
Author(s):  
Miguel A. Chiong ◽  
Henry Stefaniszyn
Keyword(s):  
Heart Rate ◽  
Energy Charge ◽  
Systolic Pressure ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Adrenergic Blockade ◽  
Enzyme Release ◽  
Ventricular Systolic Pressure ◽  
Energy Stores ◽  
Left Ventricular Systolic Pressure

The effects of 80 μM dl-propranolol on left ventricular (LV) performance, energy stores, and creatine kinase (CK) release were studied in a modified Langendorff rabbit heart preparation during 75 min of aerobic perfusion and postanoxic reoxygenation.The data showed that this concentration of propranolol, which blocked the effects of β-adrenergic stimulation without affecting LV performance, coronary sinus flow (CSF), or oxygen consumption [Formula: see text], was associated with greater stores of glycogen and adenine nucleotides at the end of aerobic perfusion. Similar effects were observed during postanoxic reoxygenation, when recoveries of left ventricular systolic pressure, heart rate, heart rate - left ventricular systolic pressure product, CSF, and [Formula: see text] remained unchanged during propranolol administration, but myocardial concentrations of glycogen, creatine phosphate, and ATP were greater and the ATP:AMP ratio and the energy charge were higher than in untreated hearts. In addition, the rate of CK loss was lower in the blocked postanoxic hearts than in the unblocked group. These results indicate that propranolol had a beneficial effect on cardiac metabolism during postanoxic recovery tending to normalize energy stores and to reduce enzyme loss during reoxygenation of perfused rabbit hearts without affecting mechanical performance, coronary flow, or O2 metabolism.

The Effect of Gypenosides on Cardiac Function and Expression of Cytoskeletal Genes of Myocardium in Diabetic Cardiomyopathy Rats

2009 ◽  
Vol 37 (06) ◽  
pp. 1059-1068 ◽  
Author(s):  
Min Ge ◽  
Shanfeng Ma ◽  
Liang Tao ◽  
Sudong Guan
Keyword(s):  
Cardiac Function ◽  
Diabetic Cardiomyopathy ◽  
Diastolic Pressure ◽  
Pure Water ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Control Group ◽  
Sprague Dawley ◽  
Gene Expressions ◽  
Ventricular Systolic Pressure

The relationship between changes of cardiac function and the gene expressions of two major myocardial skeleton proteins, titin and nebulin, and the effect of gypenosides on these gene expressions in diabetic cardiomyopathy rat were explored in the present study. Forty Sprague-Dawley rats were randomly divided into three groups: control group, diabetic cardiomyopathy group and gypenosides-treated diabetic cardiomyopathy group. The diabetic cardiomyopathy was induced in rats by injecting streptozotocin (STZ, 55 mg/kg) intraperitoneally. Seven weeks after the rats suffered from diabetes, the rats were treated with gypenosides 100 mg/kg per day orally for six weeks in gypenosides-treated group. In the meanwhile, the pure water was given to diabetic cardiomyopathy and the control groups. Subsequently, the cardiac functions, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), ± dP/dtmax and t–dP/dmaxt, as well as the mRNA content and proteins of titin and nebulin in myocardium were determined. The results indicated that (1) the diabetic cardiomyopathy rats had decreased LVSP and ± dP/dtmax, increased LVEDP, and prolonged t–dP/dtmax than normal rats; (2) LVSP and ± dP/dtmax in diabetic cardiomyopathy rats treated with gypenosides were significantly higher and LVEDP and t–dP/dtmax were significantly lower than those without giving gypenosides; (3) the mRNA contents and proteins of titin and nebulin in diabetic cardiomyopathy rats were remarkably lower than those in the control rats and gypenosides had no effect on mRNA and protein expression levels of titin and nebulin in diabetic cardiomyopathy rats. We conclude that (1) the cardiac function as well as the mRNA expressions of titin and nebulin decreased in diabetic cardiomyopathy rats; (2) gypenosides secure cardiac muscles and their function from diabetic impairment and these beneficial effects of gypenosides are not by changing the expressions of titin and nebulin.

Metabolism of the perfused rabbit heart. V. Verapamil-induced release of creatine kinase

1982 ◽  
Vol 60 (7) ◽  
pp. 952-959 ◽  
Author(s):  
Miguel A. Chiong
Keyword(s):  
Creatine Kinase ◽  
Adenine Nucleotides ◽  
Systolic Pressure ◽  
Creatine Phosphate ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Calcium Stores ◽  
Ventricular Performance ◽  
Permeability Characteristics ◽  
Energy Stores

The effects of verapamil (VER), at concentrations of 0, 10−9, 10−8, 10−7, and 5 × 10−7 M (or 0, 0.5, 5, 50, and 250 ng/mL) were studied in the isolated rabbit heart during 70 min of aerobic perfusion with a standard Krebs–bicarbonate medium at 37 °C. The studied variables were left ventricular performance (RPP, heart rate times left ventricular (LV) systolic pressure), coronary sinus flow (CSF), oxygen uptake [Formula: see text], rate of creatine kinase (CK) release, and energy stores (glycogen, creatine phosphate (CP), ATP, and total adenine nucleotides (TAN)).The results show that (i) VER depressed RPP in a dose-related manner; (ii) [Formula: see text] declined as VER concentration increased except in the 5 × 10−7 M group which showed a paradoxical increase in O2 uptake; (iii) CSF was only slightly decreased by VER with the exception of the 5 × 10−7 M group, which showed an increase in flow; (iv) VER was associated with increments in the rates of CK release in a dose-related fashion (2, 4, 15, and 29 times the rate observed in the untreated group), and (v) VER was associated with slight decrease in glycogen levels, but no changes in CP or adenine nucleotides.It is concluded that, in our preparation, VER caused marked increases in the rate of CK loss in the absence of depletion of total energy stores. The data suggest that the drug affects the permeability characteristics of the sarcolemma, perhaps via localized depletion of calcium stores.

Gender differences in the cardiac response to dietary conjugated linoleic acid isomers

2006 ◽  
Vol 84 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Paramjit S. Tappia ◽  
Rabban Mangat ◽  
Cindy Gabriel ◽  
Melissa R. Dent ◽  
Nina Aroutiounova ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Heart Rate ◽  
Heart Function ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Female Rats ◽  
Male Rats ◽  
Control Group ◽  
Ventricular Systolic Pressure ◽  
Left Ventricular Systolic Pressure

The present study was undertaken to assess the heart function, by the in vivo catheterization technique, of healthy male and female Sprague–Dawley rats fed different conjugated linoleic acid (CLA) isomers, (cis-9, trans-11 (c9,t11) and trans-10, cis-12 (t10,c12)) individually and in combination (50:50 mix as triglyceride or fatty acids) from 4 to 20 weeks of age. Whereas the triglyceride form of the CLA isomer mix lowered the heart rate, the rate of contraction (+dP/dt) and rate of relaxation (–dP/dt), systolic and diastolic pressures, mean arterial pressure, and the left ventricular systolic pressure were higher in male rats as compared with all the other dietary groups. In contrast, there were no significant effects in the cardiac function of the female rats in response to the CLA isomer mix in triglyceride form. Whereas the heart rate, +dP/dt, and left ventricular systolic pressure were lower in male rats fed the t10,c12 CLA isomer alone, the heart rate of the female rats was higher, but the systolic pressure, +dP/dt, and mean arterial pressure were lower compared with the control group. Also, the left ventricular end-diastolic pressure was specifically higher in the female rats in response to free fatty acids-containing CLA mix. Furthermore, an additive effect of the free fatty acids-containing CLA mix was seen in the +dP/dt and –dP/dt of female rats compared with the control group. These results indicate that CLA isomers exert differential effects on heart function and suggest the need for a complete evaluation of the benefits, interactions, and potential side effects of each isomer.

Influence of low extracellular Ca2+ ions on the cardiac function changes induced by verapamil in the perfused rabbit heart

1985 ◽  
Vol 63 (11) ◽  
pp. 1429-1434 ◽  
Author(s):  
Pierre A. Fortier ◽  
Gary K. Bedford ◽  
Miguel A. Chiong
Keyword(s):  
Rabbit Heart ◽  
The Other ◽  
Control Group ◽  
Enzyme Release ◽  
Control Groups ◽  
Coronary Sinus Flow ◽  
Pr Interval ◽  
Energy Stores ◽  
Group A ◽  
Sinus Flow

We tested the hypothesis that the myocardial effects of verapamil (VER) could be enhanced by decreasing the extracellular Ca2+ concentration ([Ca2+]o) in the isolated rabbit heart at 37 °C. After perfusion with standard Krebs–bicarbonate solution containing 1.27 mM Ca2+, for a 30-min period of stabilization and 15 min of control, groups of hearts were perfused for an additional 60 min with solutions containing one of the following: 1.27 mM Ca2+ (control group), 0.23 mM Ca2+ (low [Ca2+]o group), 1.27 mM Ca2+ plus 10− M VER (VER group), or 0.23 mM Ca2+ plus 10−7 M VER (combination, CBN group). These concentrations of [Ca2+]o and VER produce submaximal responses in our preparation. We found that the heart rate – LV pressure product (RPP) in the CBN group fell rapidly to 0 in the first 2–3 min of perfusion, this response being significantly lower than in the other two groups for the first 15 min. Electromechanical dissociation (EMD) appeared in one of six hearts at 60 min and in four of six hearts at 30 min in the low [Ca2+]o and VER groups, respectively, whereas it occurred in the CBN group in all hearts at 3 min. Depolarization rate (DR) fell by 10% in the low [Ca2+]o and VER groups versus a reduction of 45% in the CBN group (P < 0.05) during the last 45 min of perfusion. The PR interval increased by 300% in the CBN group, a much greater and significant change (P < 0.05) than in the hearts exposed to VER or low [Ca2+]o. The QT interval, however, increased by 50% in the low [Ca2+]o group (P < 0.05) and decreased by 20–30% in the VER and CBN groups (P < 0.05). On the other hand there were no differences in the changes in coronary sinus flow, O2 uptake, enzyme release, or energy stores among the groups. We conclude that low [Ca2+]o enhanced the effects of VER in relation only to RPP, DR, PR interval, and possibly EMD, but had no influence on metabolism.

Cardiac changes during behavioral stress in dogs

1979 ◽  
Vol 236 (5) ◽  
pp. H750-H758 ◽  
Author(s):  
R. A. Galosy ◽  
L. K. Clarke ◽  
J. H. Mitchell
Keyword(s):  
Heart Rate ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Control Group ◽  
Avoidance Task ◽  
Base Line ◽  
Sidman Avoidance ◽  
Ventricular Systolic Pressure ◽  
Behavioral Stress ◽  
Left Ventricular Systolic Pressure

Alterations in heart rate (HR), left ventricular systolic pressure (LVP), and maximum rate of left ventricular pressure development (LV dP/dtmax) during a Sidman avoidance task were studied in eight chronically prepared dogs. Four of these animals comprised a nonstressed control group. In the experimental group, in addition to phasic increases in HR, LVP, and LV dP/dtmax during the avoidance period of each day, tonic increases in these measures were also observed over the 13 days of the experiment. Left ventricular systolic pressure was found to be least sensitive to the stress procedure inasmuch as the phasic changes were no longer present after the 10th day and tonic levels were within base-line values by the 13th day. When alterations in cardiac activity were observed in the nonstressed animals, there were decreases in function. It was concluded that controlled behavioral stress produces increased cardiac performance without increased bodily activity. It was also hypothesized that preavoidance increases in heart rate in experimental animals were the result of vagal influences on the heart, whereas avoidance increases in HR, LV dP/dtmax, and LVP were functions of increased beta-sympathetic activity on the heart and adaptive peripheral vascular changes.

Abstract 16574: Heart Failure Biomarkers (NT-proBNP, Gal-3, sST2) Correlate With Right Ventricular Systolic Pressure and Provide Insight to Poor CRT Response: A BIOCRT Substudy

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Roderick C Deaño ◽  
Jackie Szymonifka ◽  
Qing Zhou ◽  
Jigar H Contractor ◽  
Zachary Lavender ◽  
...  
Keyword(s):  
Heart Failure ◽  
Right Ventricular ◽  
Systolic Pressure ◽  
Fold Increase ◽  
Left Ventricular ◽  
Cardiac Resynchronization ◽  
Cardiac Transplant ◽  
Right Ventricular Systolic Pressure ◽  
Ventricular Systolic Pressure ◽  
Crt Response

Objective: Patients with heart failure (HF) and pulmonary hypertension (PH) have worse outcomes after cardiac resynchronization therapy (CRT). The relationship of circulating HF biomarkers and right ventricular systolic pressure (RVSP) may provide insight to the mechanism between PH and poor CRT response. Methods: In 90 patients (age 65 ± 13, 78% male, EF 26 ± 8%, RVSP 44 ± 12 mmHg) undergoing CRT, we measured baseline RVSP by echocardiography and obtained peripheral blood samples drawn at the time of device implantation. We measured levels of established and emerging HF biomarkers (Table 1). CRT non-response was defined as no improvement of adjudicated HF Clinical Composite Score at 6 months. Major adverse cardiac event (MACE) was defined as composite endpoint of death, cardiac transplant, left ventricular assist device, and HF hospitalization within 2 years. Results: There were 34% CRT non-responders and 27% had MACE. Per 1 unit increase in log-transformed RVSP, there was an 11-fold increase risk of having CRT non-response (odd ratio [OR] 11.0, p=0.01) and over 5-fold increase of developing 2-year MACE (hazard ratio [HR] 5.8, p=0.02). When comparing patients with severe PH (RVSP>60 mmHg) to those without PH (RVSP < 35 mmHg), there was an 8-fold increase in CRT nonresponse (OR 8.4, p=0.03) but no difference in MACE (p=NS). RVSP was correlated with increased biomarker levels of myocardial stretch and fibrosis, but not myocardial necrosis (Table 1). Conclusions: Higher RVSP is associated with greater rates of CRT non-response and adverse clinical outcomes. The mechanistic association between severe PH and CRT nonresponse may be explained by the biomarker profile reflective of myocardial wall stretch and fibrosis.

Effect of human urotensin-II infusion on hemodynamics and cardiac function

2003 ◽  
Vol 81 (2) ◽  
pp. 125-128 ◽  
Author(s):  
Ghada S Hassan ◽  
Fazila Chouiali ◽  
Takayuki Saito ◽  
Fu Hu ◽  
Stephen A Douglas ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Diastolic Pressure ◽  
Cardiac Contractility ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Urotensin Ii ◽  
Ventricular Systolic Pressure ◽  
Wide Range ◽  
Dose Dependent Decrease

Recent studies have shown that the vasoactive peptide urotensin-II (U-II) exerts a wide range of action on the cardiovascular system of various species. In the present study, we determined the in vivo effects of U-II on basal hemodynamics and cardiac function in the anesthetized intact rat. Intravenous bolus injection of human U-II resulted in a dose-dependent decrease in mean arterial pressure and left ventricular systolic pressure. Cardiac contractility represented by ±dP/dt was decreased after injection of U-II. However, there was no significant change in heart rate or diastolic pressure. The present study suggests that upregulation of myocardial U-II may contribute to impaired myocardial function in disease conditions such as congestive heart failure.Key words: urotensin-II, rat, infusion, heart.

scholarly journals Effects of Long-term Nonylphenol Exposure on Myocardial Fibrosis and Cardiac Function in Rats

2021 ◽  
Author(s):  
Chao Liu ◽  
Chengyu Ni ◽  
Weichu Liu ◽  
Xiaolian Yang ◽  
Renyi Zhang ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Myocardial Fibrosis ◽  
Posterior Wall ◽  
Anterior Wall ◽  
Left Ventricular ◽  
Environmental Estrogens ◽  
Control Group ◽  
Cardiac Structure ◽  
Collagen Iii

Abstract Background: Myocardial fibrosis is a critical pathological basis for the poor prognosis of cardiovascular diseases. Studies have found that myocardial fibrosis is closely associated with exposure to environmental estrogens such as nonylphenol (NP), as a representative of environmental estrogens. The aim of this study was to examine the effects of NP chronic exposure on myocardial fibrosis as well as cardiac structure and function. Forty Sprague Dawley rats were randomly divided into four groups (n = 10): control group (C), low NP dose (0.4 mg/kg, L), medium NP dose (4 mg/kg, M), and high NP dose (40 mg/kg, H) groups. The NP dose groups were gavaged with NP for 180 days. Results: The NP level in the heart of the NP groups was significantly higher than those in the control group (F = 43.658, P < 0.001). Serum aspartate aminotransferase (AST), creatine kinase (CK), creatine kinase isozyme (CK-MB), lactate dehydrogenase (LDH) and α-hydroxybutyrate dehydrogenase (α-HBDH) significantly increased in the NP groups compared with the control group (). Histopathological examination of the heart biopsy illustrates that in the medium and high NP groups, the fibrous connective tissue had a disordered and loose gridding shape, muscle fibers had fractured, and muscle fibers were loose with a widened gap. Extensive inflammatory cell infiltration and fibroblast proliferation in the myocardial interstitium were also found. With increasing NP dose, the degree of muscle fiber loosing and disorder became more significant in the NP treatment groups, and the collagen volume fraction (CVF) was higher than that in the control group (P < 0.01). Compared with the control group, the expression of collagen I and collagen III increased significantly in the medium and high NP groups (P < 0.05). The values of the systolic thickness of the left ventricular anterior wall (LVAWs), the diastolic thickness of the left ventricular posterior wall (LVPWd), the systolic thickness of the left ventricular posterior wall (LVPWs), and the left ventricular anterior wall (LVAWd) in the NP groups are were slightly lower than those in of the control group. The values of left ventricular end systolic dimensions (LVIDs) in the NP groups increased compared with the control group. Conclusions: Long-term NP exposure could lead to fibrosis in the rat myocardium, which is characterized by increased expressions of myocardial collagen I and collagen III, as well as elevated cardiac enzymes. In addition, the cardiac structure was affected and changes were observed in the thinner ventricular wall and as an enlarged ventricular cavity.

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