ABSTRACT
Novel strategies are evaluated for management of allergic rhinitis and asthma in patients co-afflicted with both disorders. It is hypothesized that the platelet activating factor receptor antagonist ginkgolide B (GB) and the carotenoid antioxidant astaxanthin (ASX) interact with antihistamines cetirizine dihydrochloride (CTZ) and azelastine (AZE) to potentiate their ability to downregulate potentially pathological immune activation. Peripheral blood mononuclear cells from asthmatics and healthy subjects, cultured 24 hours with 50 µg/ml phytohemaglutinin (PHA) or PHA plus each drug are analyzed by flow cytometry for expression of CD25+ or HLA-DR+ by CD3+ (T cells). Results are reported as stimulation indices for CD3+CD25+ (SICD3+CD25+) and CD3+HLA-DR+ (SICD3+HLADR+) cells in cultures treated with PHA alone, versus cultures treated with both PHA and drugs. Optimal suppression of activated cells was observed in cultures stimulated with ASX 10-6 M + CTZ 10-6 M (SICD3+CD25+, p = 0.016; SICD3+HLADR, p = 0.012); ASX 10-6 M + AZE 10-6 M (SICD3+CD25+, p = 0.012; SICD3+HLADR, p = 0.015); GB 10-6 M + CTZ 10-6 M (SICD3+CD25+, p = 0.024, SICD3+HLADR+, p = 0.019). Results demonstrate improved activity of antihistamines by 2 phytochemicals, suggesting dosing strategies for animal trials of ASX- or GB-augmented formulations for seasonal allergic rhinitis and asthma.
Subject(s)
Anti-Allergic Agents/pharmacology , Antioxidants/pharmacology , Asthma/drug therapy , Cetirizine/pharmacology , Ginkgolides/pharmacology , Lactones/pharmacology , Lymphocyte Activation/drug effects , Phthalazines/pharmacology , Rhinitis, Allergic, Seasonal/drug therapy , T-Lymphocytes/drug effects , Adult , Asthma/immunology , Biomarkers/metabolism , Case-Control Studies , Cells, Cultured , Drug Therapy, Combination , Female , Flow Cytometry , Histamine H1 Antagonists, Non-Sedating/pharmacology , Humans , Male , Platelet Membrane Glycoproteins/antagonists & inhibitors , Platelet Membrane Glycoproteins/metabolism , Receptors, G-Protein-Coupled/antagonists & inhibitors , Receptors, G-Protein-Coupled/metabolism , Rhinitis, Allergic, Seasonal/immunology , T-Lymphocytes/immunology , Xanthophylls/pharmacology , Young AdultABSTRACT
OBJECTIVE: The results of reported lymphaticovenous anastomoses include some effects of complex decongestive physiotherapy (CDP). The present study aimed to determine the net effect of lymphaticovenous side-to-end anastomosis (LVSEA) in patients with lower limb lymphoedema treated by preoperative CDP. DESIGN: Retrospective observational study. MATERIALS: 37 LVSEAs in 31 patients. METHODS: Volumes of the thigh and leg with oedema were compared between the time of initial examination, and before (application of CDP) and after LVSEA. The patients were divided into two groups based on the number of anastomoses and lymphoscintigraphic findings. RESULTS: Preoperative CDP resulted in a reduction of 593 ml (both leg and thigh; p < 0.001). After CDP, LVSEA (1-8 anastomoses; average of 5) reduced the volume by 109 ml (52 ml for the thigh (p = 0.01) and 57 ml for the leg (p = 0.002)). There was no significant difference in volume reduction on lymphoscintigraphy. Volume was significantly reduced (by 55 ml in the thigh, p = 0.049; 96 ml in the leg, p = 0.006) in the group that underwent 6-8, but not 1-5 LVSEAs. CONCLUSIONS: The net effect of LVSEA on volume reduction was confirmed, but was not particularly large. The need for CDP decreased in some patients postoperatively, and these patients should be considered for evaluation.
Subject(s)
Lower Extremity/blood supply , Lymphatic Vessels/surgery , Lymphedema/surgery , Neoplasms/complications , Physical Therapy Modalities , Veins/surgery , Adult , Aged , Anastomosis, Surgical , Chronic Disease , Female , Humans , Leg , Lymphedema/diagnostic imaging , Lymphedema/therapy , Lymphoscintigraphy , Middle Aged , Retrospective Studies , Uterine Neoplasms/therapy , Vascular Surgical ProceduresABSTRACT
The present review examines the role of the cytoprotective enzyme haeme oxygenase-1 (HO-1) in adaptive responses to inflammatory disease and explores strategies for its clinical use, with particular emphasis on use of therapeutic use of the enzyme using phytochemical inducers of HO-1 such as extracts of Ginkgo biloba, curcumin, and flavonoids extracted from seeds of the sour cherry (Prunus cerasus). This laboratory has identified strategies by which combinations of dietary phytochemicals may be configured to synergistically strengthen immunoregulatory mechanisms that normally prevent inflammation from leading to disease. A major focus of this research initiative has been HO-1, which is capable of substantially reducing oxidative stress by several mechanisms. HO-1 metabolizes haeme that accumulates in tissues because of red blood cell turnover. Two products of this degradation - carbon monoxide (CO) and bilirubin - have potent capacity for reducing oxidative stress and for counteracting its effects. A description will be provided of how HO-1 products maintain healthy tissue function and remediate oxidative tissue damage. This will be explored in four major organ systems, including the cardiovascular system, the lungs, the central nervous system and the kidneys. Particular focus will be given to the physiological coordination of cardiovascular functions mediated by CO produced by HO-1 and to nitric oxide (NO), a gaseous second messenger expressed by nitric oxide synthetase. A major unifying theme of the present review is an exploration of the potential use of dietary phytochemical formulations as tools for the clinical application of HO-1 in therapeutic reduction of oxidative stressors, with resultant improved treatment of inflammatory pathologies.
Subject(s)
Antioxidants/metabolism , Heme Oxygenase-1/metabolism , Inflammation/metabolism , Oxidative Stress/physiology , Animals , Humans , Inflammation/pathologyABSTRACT
Leptin is known to exert cardiodepressive effects and to induce left ventricular (LV) remodelling. Nevertheless, the autocrine and/or paracrine activities of this adipokine in the context of post-infarct dysfunction and remodelling have not yet been elucidated. Therefore, we have investigated the evolution of myocardial leptin expression following myocardial infarction (MI) and evaluated the consequences of specific cardiac leptin inhibition on subsequent LV dysfunction. Anaesthetized rats were subjected to temporary coronary occlusion. An antisense oligodesoxynucleotide (AS ODN) directed against leptin mRNA was injected intramyocardially along the border of the infarct 5 days after surgery. Cardiac morphometry and function were monitored by echocardiography over 11 weeks following MI. Production of myocardial leptin and pro-inflammatory cytokines interleukin (IL)-1ß and IL-6 were assessed by ELISA. Our results show that (1) cardiac leptin level peaks 7 days after reperfused MI; (2) intramyocardial injection of leptin-AS ODN reduces early IL-1ß and IL-6 overexpression and markedly protects contractile function. In conclusion, our findings demonstrate that cardiac leptin expression after MI could contribute to the evolution towards heart failure through autocrine and/or paracrine actions. The detrimental effect of leptin could be mediated by pro-inflammatory cytokines such as IL-1ß and IL-6. Our data could constitute the basis of new therapeutic approaches aimed to improve post-MI outcome.
Subject(s)
Leptin/metabolism , Myocardial Infarction/metabolism , Myocardium/metabolism , Ventricular Dysfunction, Left/metabolism , Animals , DNA, Antisense/administration & dosage , DNA, Antisense/genetics , Echocardiography , Enzyme-Linked Immunosorbent Assay , Heart/drug effects , Heart/physiopathology , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Leptin/genetics , Male , Myocardial Infarction/physiopathology , Myocardium/pathology , Rats , Rats, Wistar , Time Factors , Ventricular Dysfunction, Left/physiopathologyABSTRACT
Several beta-cyclodextrin (beta-CD) derivatives have been synthesized recently to improve the physicochemical properties and inclusion capacities of the parent molecule, however, there is limited information available about their cytotoxic effects. In this study we investigated the cytotoxic and hemolytic properties of various beta-CDs in correlation with their cholesterol-solubilizing capacities to expose the mechanism of toxicity. MTT cell viability test, performed on Caco-2 cells showed significant differences between the cytotoxicity of beta-CD derivatives. Cell toxicity of methylated-beta-CDs was the highest, while ionic derivatives proved to be less toxic than methylated ones. Most of the second generation beta-CD derivatives, having both ionic and methyl substituents showed less cytotoxicity than the parent compounds both on Caco-2 cells and human erythrocytes. Inclusion of cholesterol into the ring of randomly methylated-beta-CD and heptakis(2,6-di-O-methyl)-beta-CD abolished the cell toxicity indicating the role of cholesterol extraction in cytotoxicity. These data demonstrate the correlation between the cytotoxic effect, hemolytic activity and the cholesterol complexation attributes of beta-CD derivatives and we propose that cholesterol-solubilizing properties can be a predictive factor for beta-CD cell toxicity.
Subject(s)
Cholesterol/chemistry , Excipients/toxicity , Hemolytic Agents/toxicity , beta-Cyclodextrins/chemistry , beta-Cyclodextrins/toxicity , Caco-2 Cells , Cell Survival/drug effects , Erythrocytes/drug effects , Excipients/chemistry , Hemolysis/drug effects , Hemolytic Agents/chemistry , Humans , Inhibitory Concentration 50 , Methylation , Solubility , Structure-Activity RelationshipABSTRACT
Recent studies suggest that glutaredoxin-1 (Glrx-1) may serve as therapeutic target for diabetic hearts. As the level of reactive oxygen species (ROS) is increased in the pathologic hearts including ischemia/reperfusion (I/R) and diabetes, we assumed that upregulation of Glrx-1 could reduce the cardiac risk factors associated with I/R and/or diabetes. Diabetes was induced in mice by i.p. injection of streptozotocin (150 mg kg(-1)). Eight days after when the blood glucose was elevated to 400 mg per 100 ml, the animals were randomly assigned to one of the following three groups, which received either empty vector, or LacZ or Glrx-1 adenoviral construct. Four days later, isolated working hearts were subjected to 30 min ischemia followed by 2 h reperfusion. Glrx-1 gene therapy significantly enhanced the Glrx-1 level, which prevented I/R-mediated reduction of ventricular recovery, increased myocardial infarct size and cardiomyocyte apoptosis in diabetic myocardium. In concert, Glrx-1 prevented diabetes and ischemia-reperfusion induced reduction of cardioprotective proteins including Akt, FoxO-1, and hemeoxygenase-1, and abolished the death signal triggered by Jnk, p38 mitogen-activated protein kinase, and c-Src. Glrx-1 gene therapy seems to prevent cardiac complications in diabetic heart due to the I/R by switching the death signal into survival signal by activating Akt-FoxO-signaling network.
Subject(s)
Diabetes Mellitus, Experimental/metabolism , Genetic Therapy/methods , Glutaredoxins/metabolism , Reperfusion Injury/therapy , Signal Transduction/genetics , Adenoviridae , Animals , Forkhead Box Protein O1 , Forkhead Transcription Factors/metabolism , Glutaredoxins/genetics , Heme Oxygenase-1/metabolism , Immunohistochemistry , Mice , Myocardium/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Reactive Oxygen Species/metabolism , Reperfusion Injury/geneticsSubject(s)
Adenosine Triphosphate/biosynthesis , GTP-Binding Proteins/metabolism , Myocardial Reperfusion Injury/prevention & control , Myocytes, Cardiac/metabolism , Transglutaminases/metabolism , Animals , GTP-Binding Proteins/deficiency , GTP-Binding Proteins/genetics , In Vitro Techniques , Male , Membrane Potentials , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitochondria, Heart/metabolism , Myocardial Reperfusion Injury/metabolism , Myocytes, Cardiac/cytology , Protein Glutamine gamma Glutamyltransferase 2 , Receptors, Adrenergic, alpha-1/deficiency , Receptors, Adrenergic, alpha-1/genetics , Receptors, Adrenergic, alpha-1/metabolism , Signal Transduction , Transglutaminases/deficiency , Transglutaminases/geneticsABSTRACT
Isolated rat hearts were perfused for 10 min with oxygenated buffer and equilibrated with carbon monoxide (CO) of 0.001% and 0.01% before the induction of 30 min global ischemia followed by 120 min of reperfusion. These concentrations of CO significantly improved the post-ischemic recovery of coronary flow (CF), aortic flow (AF), and left ventricular developed pressure (LVDP). The improvement in recovery reflected in the reduction of infarct size and the incidence of reperfusion-induced ventricular fibrillation (VF). Thus, hearts subjected to 0.001% and 0.01% of CO exposure via the perfusion buffer, infarct size was reduced from the CO-free control value of 39% +/- 5% to 21% +/- 3% (*p<0.05) and 18% +/- 4% (*p<0.05), respectively. In the presence of 0.001% and 0.01% CO, the incidence of VF was also reduced from its control value of 92% to 17% (*p<0.05) and 17% (*p<0.05), respectively. Increasing the CO exposure to 0.1% in the buffer, all hearts showed VF combined with ventricular tachycardia or bradycardia and various rhythm disturbances indicating the direct toxic effects of CO on the myocardium. The results show that cardioprotective concentrations (0.01% and 0.001%) of exogenous CO related to an increase in cGMP levels and guanylate cyclase activities.
Subject(s)
Carbon Monoxide/pharmacology , Cardiotonic Agents/pharmacology , Heart/drug effects , Myocardial Ischemia/therapy , Animals , Arrhythmias, Cardiac/chemically induced , Arrhythmias, Cardiac/prevention & control , Cyclic GMP/metabolism , Dose-Response Relationship, Drug , Guanylate Cyclase/metabolism , Heart/physiopathology , In Vitro Techniques , Male , Myocardial Ischemia/complications , Rats , Rats, Sprague-Dawley , Regional Blood Flow/drug effectsABSTRACT
The cardioprotective effects of red wine have been attributed to several polyphenolic antioxidants including resveratrol and proanthocyanidins. The goal of the present study was to determine whether white wines could also provide cardioprotection. Three different white wines (white wine #1, #2 and #3) were chosen for this study. Ethanol-free extracts of the wines were prepared by vacuum evaporation. Rats weighing approximately 200 g were given either 50 mg/kg or 100 mg/kg of each wine extract for 3 weeks. The rats were anesthetized and sacrificed and their hearts were excised for the preparation of isolated working rat heart. All hearts were subjected to 30 min of global ischemia followed by 2 h of reperfusion. Cardiac function including heart rate, left ventricular developed pressure (LVDP), maximum first derivative of developed pressure (LVdp/dtmax), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEP), aortic flow (AF) and coronary flow (CF) were continuously monitored and myocardial infarct size was measured at the end of the experiments. The results of our study demonstrated that among the three different white wines, only white wine #2 conferred cardioprotection as evidenced by improved postischemic ventricular recovery compared with controls. The same white wine at a dose of 50 mg/kg also showed improvement in postischemic contractile recovery but the differences compared with controls were not significant. The amount of malondialdehyde production from these hearts was lower than that found in control hearts, indicating reduced formation of reactive oxygen species in white wine #2-treated rats. In vitro studies using a chemiluminescence technique revealed that white wine #2 scavenged both superoxide anions and hydroxyl radicals. The results of our study demonstrate that white wine #2 provided cardioprotection and the cardioprotective effect of the wine can be attributed, at least in part, to its ability to function as an in vivo antioxidant.
Subject(s)
Flavonoids , Heart/physiopathology , Myocardial Ischemia/prevention & control , Wine , Animals , Chromatography, High Pressure Liquid , Hydroxyl Radical/analysis , In Vitro Techniques , Male , Malondialdehyde/analysis , Myocardial Infarction/pathology , Myocardial Infarction/prevention & control , Myocardial Ischemia/pathology , Myocardial Ischemia/physiopathology , Myocardium/pathology , Phenols/analysis , Polymers/analysis , Polyphenols , Rats , Rats, Sprague-Dawley , Superoxides/analysis , Ventricular Function/drug effects , Wine/analysisABSTRACT
The mechanism of cardioprotection with red wine consumption was studied by examining the antideath signaling cascade of one of the principle components of red wine, proanthocyanidins. Grape seed proanthocyanidin extract (GSPE) was administered orally (100 mg/kg/d) supplemented with regular diet for 3 weeks to a group of rats while the other group was given the regular diet only for the same period of time. After 3 weeks, rats were sacrificed, hearts excised, and perfused via Langendorff mode. After stabilization, hearts were perfused in the working mode for baseline measurement of contractile function. Hearts were then made globally ischemic for 30 min followed by 2 h of reperfusion. Contractile function was continuously monitored during reperfusion, and free radical production was examined by electron spin resonance (ESR) technique. Cardiomyocyte apoptosis was examined by TUNEL staining in conjunction with an antibody against myocin heavy chain to specifically detect myocytes. Induction of JNK-1 and c-fos proteins was studied by Western blot analysis using respective antibodies followed by densitometric scanning. The results indicated significant induction of JNK-1 and c-fos proteins in the ischemic/reperfused myocardium, which was inhibited by the proanthocyanidin extract. In concert, GSPE significantly reduced the appearance of apoptotic cardiomyocytes in the ischemic/reperfused hearts. GSPE also significantly reduced the appearance of the reactive oxygen species in the hearts. Improved postischemic contractile recovery was achieved with GSPE suggesting its cardioprotective action. The results of this study indicated that GSPE functioned as an in vivo antioxidant, and its cardioprotective properties may be at least partially attributed to its ability to block antideath signal through the inhibition of proapoptotic transcription factor and gene, JNK-1 and c-Jun.
Subject(s)
Anthocyanins/pharmacology , Apoptosis/drug effects , Mitogen-Activated Protein Kinases/metabolism , Myocardial Ischemia/metabolism , Proanthocyanidins , Proto-Oncogene Proteins c-jun/metabolism , Vitis/chemistry , Animals , Antioxidants/pharmacology , Electron Spin Resonance Spectroscopy , Enzyme Activation/drug effects , Free Radicals , Male , Mitogen-Activated Protein Kinase 8 , Myocardial Ischemia/pathology , Myocardial Reperfusion , Myocardium/pathology , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/analysis , Seeds/chemistryABSTRACT
In isolated working rat heart, capsaicin elicited a concentration-dependent constriction of coronary arteries accompanied by decline of all cardiac parameters recorded (heart rate, coronary and aortic flow, left ventricular developed pressure, and first derivative of left ventricular developed pressure). The following evidence suggests that capsaicin-induced changes are mediated by endothelin of neural origin: (1) the capsaicin (10 nM)-evoked decrease in coronary flow resulting in deterioration of cardiac functions was mimicked by endothelin (0.1 nM); (2) the selective endothelin ET(A) receptor antagonist, cyclo (D-alpha-aspartyl-L-propyl-D-valyl-L-leucyl-D-tryptophyl) (1 microM), abolished the cardiac effects provoked by capsaicin (10 nM); (3) reduction of extracellular Ca2+ concentration from 2.4 to 1.2 or 0.6 mM inhibited the cardiac effects of capsaicin (10 nM) but not those induced by endothelin (0.1 nM); (4) perfusion of the heart with 0.1% (v/v) Triton X-100 damaged the endothelium and reversed the enhancement of coronary flow evoked by bethanechol (1 microM), decreased the basal flow, but was without effect on capsaicin-induced coronary constriction; (5) in response to capsaicin challenge (10-100 nM), the endothelin concentration measured in coronary effluent by means of radioimmunoassay increased up to sevenfold but remained unchanged in the presence of 0.6 mM Ca2+; (6) no reduction of coronary flow was induced by capsaicin (100 nM) applied to the heart of rats which were desensitised by capsaicin (150 mg/kg). It is concluded that, in the rat heart, capsaicin acting on VR1 capsaicin receptors elicits a release of endothelin from the sensory nerve terminals.
Subject(s)
Antihypertensive Agents/pharmacology , Capsaicin/pharmacology , Endothelins/metabolism , Heart/drug effects , Neurons, Afferent/drug effects , Peptides, Cyclic/pharmacology , Analysis of Variance , Animals , Bethanechol/pharmacology , Coronary Circulation/drug effects , Dose-Response Relationship, Drug , Drug Interactions , Endothelins/pharmacology , Heart Rate/drug effects , Male , Parasympathomimetics/pharmacology , Rats , Rats, Sprague-DawleyABSTRACT
We have assessed the relationship between reperfusion-induced ventricular fibrillation (VF) and heme oxygenase (HO) mRNA expression using northern blotting, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme activity in isolated working ischemic/reperfused rat hearts. Isolated hearts were subjected to 30 min of global ischemia followed by 120 min of reperfusion. Upon reperfusion with VF, cardiac function was registered (n = 6 in each group), and HO mRNAs and enzyme activities were measured at the end of reperfusion in hearts that showed VF or did not develop VF. The expression of HO-1 mRNA (about fourfold) was observed in ischemic/reperfused nonfibrillated myocardium in comparison with the nonischemic control hearts. In those hearts when VF was developed, the expression of HO-1 mRNA was not observed in comparison with the nonischemic control myocardium. The results measured by RT-PCR and enzyme analysis support the data obtained by northern blotting. In additional studies, we decided to approach the question from a different angle. Thus, the purpose of our work was also to study the role of HO expression and enzyme activity in electrically fibrillated hearts without the ischemic/reperfused protocol. To simulate the period of 10 min of reperfusion-induced VF, hearts were electrically fibrillated, then defibrillated, and perfused for an additional 110 min, and HO-1 mRNA expression and enzyme activities were determined. Thus, electrically induced VF resulted in about 60%, 60%, and 70% reduction in HO-1 mRNA expression, RT-PCR signal intensity, and enzyme activity, respectively, compared with the nonfibrillated ischemic/reperfused group. In conclusion, our data provide evidence that the development of reperfusion-induced VF inhibits HO-1 mRNA expression and enzyme activity in both electrically fibrillated myocardium and ischemic/reperfused fibrillated hearts. The results clearly show that HO-1 mRNA expression and enzyme activity were increased in ischemic/reperfused nonfibrillated myocardium, suggesting that interventions that are able to increase HO-1 mRNA expression and enzyme activity may prevent the development of VF.
Subject(s)
Heme Oxygenase (Decyclizing)/metabolism , Myocardial Reperfusion Injury/enzymology , Ventricular Fibrillation/enzymology , Animals , Blotting, Northern , DNA Primers/chemistry , Heme Oxygenase (Decyclizing)/genetics , Male , Myocardium/enzymology , RNA, Messenger/biosynthesis , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Myocardial ischaemia and reperfusion lead to myocardial cell death due, at least in part, to apoptotic mechanisms. Although cysteinyl aspartate-specific proteinase (caspase) activation is a major event and the most-cited culprit in the development of apoptosis, its potential contribution to ischaemic myocardial cell death is largely unknown. To study the role of caspase activation, isolated rat hearts (n=6 per group) were subjected to 30 min coronary artery occlusion followed by 120 min reperfusion. A non-selective [0.1 or 0.5 microM acetyl-Tyr-Val-Ala-Asp chloromethylketone (YVAD-cmk)] or selective caspase inhibitors [0.07 or 0.2 microM acetyl-Asp-Glu-Val-Asp-cmk (Ac-DEVD-cmk, caspase-3 inhibitor); 0.07 or 0.2 microM benzoxycarbonyl-Leu-Glu-OMe-His-Asp(OMe)-fluoromethylketone (z-LEHD-fmk, caspase-9 inhibitor)] were added to the perfusate at the start of reperfusion. Non-selective caspase inhibition with 0.1 or 0.5 microM YVAD-cmk limited infarct size: (21 +/- 4%, P<0.05; 17 +/- 3%, P<0.05, respectively) compared with the ischaemic/reperfused control (32 +/- 5%). In hearts treated with 0.1 or 0.5 microM caspase II non-selective inhibitor, the fraction of terminal-deoxynucleotidyl-transferase deoxyuridine nick end labelling (TUNEL)-positive myocyte nuclei in the infarcted zone was reduced from the ischaemic/reperfused non-treated control of 11.2 +/- 2.1% to 6.2 +/- 1.6% (P<0.05) and 1.2 +/- 0.2% (P<0.05), respectively. The recovery of post-ischaemic cardiac function (coronary flow, aortic flow and left-ventricular developed pressure) improved significantly with the application of the non-selective caspase inhibitor as well. In hearts perfused with specific caspase inhibitors (caspase-3 and caspase-9) there was no significant reduction in the infarct size, no improvement in post-ischaemic cardiac function and no reduction of apoptotic cell death. We conclude that non-specific inhibition of caspases may be therapeutically beneficial in myocardial ischaemia/reperfusion-induced damage, while selective caspase inhibitors may fail to prevent such reperfusion-induced injury in our model system.
Subject(s)
Caspase Inhibitors , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Heart/drug effects , Myocardial Infarction/drug therapy , Myocardial Reperfusion Injury/drug therapy , Animals , Apoptosis/drug effects , Apoptosis/physiology , Caspase 3 , Caspase 9 , Caspases/metabolism , Caspases/physiology , Heart/physiology , In Vitro Techniques , Myocardial Infarction/enzymology , Myocardial Reperfusion Injury/enzymology , Myocardium/enzymology , Rats , Rats, Sprague-DawleyABSTRACT
Resveratrol and trans-resveratrol are powerful phytoestrogens, present in the skins of grapes and other plant foods and wine, which demonstrate a broad spectrum of pharmacological and therapeutic health benefits. Phytoestrogens are naturally occurring plant-derived nonsteroidal compounds that are functionally and structurally similar to steroidal estrogens, such as estradiol, produced by the body. Various studies, reviewed herein, have demonstrated the health benefits of phytoestrogens in addressing climacteric syndrome including vasomotor symptoms and postmenopausal health risks, as well as their anticarcinogenic, neuroprotective and cardioprotective activities and prostate health and bone formation promoting properties. Conventional HRT drugs have been demonstrated to cause serious adverse effects including stroke and gallbladder disease, as well as endometrial, uterine and breast cancers. Recent research demonstrates that trans-resveratrol binds to human estrogen receptors and increases estrogenic activity in the body. We investigated the effects of protykin, a standardized extract of trans-resveratrol from Polygonum cuspidatum, on cardioprotective function, the incidence of reperfusion-induced arrhythmias and free radical production in isolated ischemic/reperfused rat hearts. The rats were orally treated with two different daily doses of protykin for 3 weeks. Coronary effluents were measured for oxygen free radical production by electron spin resonance (ESR) spectroscopy in treated and drug-free control groups. In rats treated with 50 and 100 mg/kg of protykin, the incidence of reperfusion-induced ventricular fibrillation was reduced from its control value of 83% to 75% (p < 0.05) and 33% (p < 0.05), respectively. Protykin was seen to possess cardioprotective effects against reperfusion-induced arrhythmias through its ability to reduce or remove the reactive oxygen species in ischemic/reperfused myocardium. Taken together, these data suggest that trans-resveratrol supplementation may be a potential alternative to conventional HRT for cardioprotection and osteoporosis prevention and may confer other potential health benefits in women.
Subject(s)
Anticarcinogenic Agents/therapeutic use , Estrogens, Non-Steroidal/therapeutic use , Isoflavones , Proanthocyanidins , Stilbenes/therapeutic use , Animals , Anthocyanins/therapeutic use , Antioxidants/therapeutic use , Dose-Response Relationship, Drug , Female , Free Radicals/antagonists & inhibitors , Heart Diseases/prevention & control , Humans , Phytoestrogens , Plant Preparations , Rats , Rats, Sprague-Dawley , Reperfusion Injury/prevention & control , Resveratrol , Ventricular Fibrillation/prevention & controlABSTRACT
Little is known concerning the effect of oxidative stress on the expression of antioxidative enzymes in the decompensated cardiac hypertrophy of spontaneously hypertensive rats (SHR), considered as a model of dilative cardiomyopathy in man. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) were characterized in isolated perfused hearts of 18 month old SHR and the age-matched normotensive control Wistar-Kyoto (WKY) rats, before and after 30 min infusion of 25 microM H(2)O(2). After infusion of H(2)O(2), aortic flow decreased in WKY from 26.2 +/- 2.2 to 16.0 +/- 0.8 ml/min (p <.05) but not in SHR (18.2 +/- 1.9 vs. 20.7 +/- 2.2 ml/min). This protection was related to the higher myocardial activities of GPx, MnSOD and CuZnSOD in SHR, compared with those of the WKY group. Although total SOD activity in the SHR fell after H(2)O(2) exposure (to 1.81 +/- 0.13 from 3.56 +/- 0.49 U/mg of protein), catalase activity increased (to 2.46 +/- 0.34 from 1.56 +/- 0.29 k min(-1)mg(-1)protein), compared with the pre-infusion period (p <.05 in each case). In additional studies, hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion. The results obtained in ischemic/reperfused hearts show the same changes in enzyme activities measured as it was observed in H(2)O(2) perfused hearts, indicating that oxidative stress is independent of the way it was induced. The higher catalase activity derived from elevated mRNA synthesis. The antioxidative system in dilative cardiomyopathic hearts of SHR is induced, probably due to episodes of oxidative stress, during the process of decompensation. This conditioning of the antioxidative potential may help overcome acute stress situations caused by reactive oxygen species in the failing myocardium.
Subject(s)
Catalase/genetics , Gene Expression Regulation, Enzymologic/physiology , Glutathione Peroxidase/genetics , Hydrogen Peroxide/pharmacology , Hypertension/enzymology , Myocardium/enzymology , Oxidative Stress , Superoxide Dismutase/genetics , Animals , Catalase/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Glutathione Peroxidase/metabolism , Hypertension/genetics , Male , RNA, Messenger/genetics , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Reverse Transcriptase Polymerase Chain Reaction , Superoxide Dismutase/metabolism , Transcription, Genetic/drug effectsABSTRACT
Effects of the calcineurin inhibitor FK506, the platelet-activating factor (PAF) antagonist, and free radical scavenger Ginkgo biloba extract, EGb 761, and their combination on reperfusion-induced ventricular fibrillation (VF), ventricular tachycardia (VT), and recovery of cardiac function were studied after 30 min of global ischemia followed by 2 h of reperfusion in isolated rat hearts. In the first series of studies, rats received a daily (oral) dose of 0, 1, 5, 10, 20, or 40 mg/kg/day FK506 for 10 days. FK506 dose-dependently reduced the incidence of reperfusion-induced total (irreversible plus reversible) VF from a value of 92% for untreated animals to 92% (NS), 83% (NS), 67% (NS), 33% (p<0.05), and 25% (p<0.05), for doses of 1-40 mg/kg/day, respectively, with effects on incidence of VT showing the same pattern. FK506, between 20 and 40 mg/kg/day, also resulted in significant recovery of postischemic cardiac function. In the second series of studies, rats were treated with EGb 761 alone or in combination with FK506. Whereas no significant reduction in arrhythmias or improvement in cardiac function resulted from a single intervention of EGb 761 at 25 mg/kg/day, combined treatment of rats with 25 mg/kg/day of EGb 761 and 1 or 5 mg/kg/day of FK506 resulted in a reduction in total and irreversible VF of 92% and 92% to 42% (p<0.05) and 33% (p<0.05), 25% (p<0.05) and 8% (p<0.05), respectively, versus untreated control animals, paralleled by similar effects on the incidence of VT and accompanied by significant improvements in postischemic cardiac function. Our results demonstrate a novel cardioprotective characteristic of FK506 and suggest that combination therapy by using FK506 plus EGb 761 synergistically improves postischemic cardiac function, while reducing the incidence of reperfusion-induced VF and VT, which may expand the clinical utility of FK506 and allow therapy with FK506 at lower doses than are currently useful.
Subject(s)
Calcineurin Inhibitors , Flavonoids/pharmacology , Free Radical Scavengers/pharmacology , Ginkgo biloba , Myocardial Reperfusion Injury/prevention & control , Plant Extracts , Plants, Medicinal , Platelet Activating Factor/metabolism , Platelet Membrane Glycoproteins/antagonists & inhibitors , Receptors, Cell Surface , Receptors, G-Protein-Coupled , Reperfusion Injury/prevention & control , Tacrolimus/pharmacology , Animals , Dose-Response Relationship, Drug , Electrocardiography/drug effects , Hemodynamics/drug effects , In Vitro Techniques , Male , Rats , Rats, Sprague-DawleyABSTRACT
BACKGROUND: Morpholinosydnonimine, a nitric oxide (NO) donor, has been reported to inhibit insulin release in isolated pancreatic islets. We studied whether transdermal application of nitroglycerin, another NO donor widely used for angina prophylaxis, influenced glucose-stimulated insulin release in healthy, young, male volunteers. METHODS AND RESULTS: Oral glucose tolerance tests [(OGTT) 75 g glucose in 200 mL of water) were performed in the presence of placebo patches or nitroglycerin-releasing 'active' patches (approx. 0.4 mg hour-1 nitroglycerin) in the same patients with a 2-week intertest interval. Venous blood samples were taken before and 15, 30, 60, 90, 120 and 180 min after the glucose load and evaluated for plasma glucose level and immunoreactive insulin responses (radioimmunoassay). Glucose-stimulated maximum increase in plasma insulin immunoreactivity were 36.3 +/- 5 and 78.8 +/- 6.1 mU mL-1 (P < 0.05) in the presence of active and placebo patches, respectively. Nevertheless, both fasting and postload blood glucose levels were the same at either patch. Active patches significantly decreased blood pressure with a marginal increase in heart rate. CONCLUSION: We conclude that inhibition of glucose-stimulated insulin release by transdermal nitroglycerin without causing hyperglycaemia may serve as a novel component of the antianginal mechanism of action of nitrates.
Subject(s)
Glucose/pharmacology , Insulin/metabolism , Nitroglycerin/administration & dosage , Vasodilator Agents/administration & dosage , Administration, Cutaneous , Adult , Double-Blind Method , Humans , Insulin Secretion , MaleABSTRACT
1. We have recently demonstrated that glyceryl trinitrate (GTN) exerts a direct myocardial anti-ischaemic effect in both GTN-tolerant and nontolerant rats. Here we examined if this effect is mediated by GTN-derived nitric oxide (NO) and involves guanosine 3'5' cyclic monophosphate (cyclic GMP) and ATP-sensitive K+ channels (KATP). 2. Rats were treated with 100 mg kg-1 GTN or vehicle s.c. three times a day for 3 days to induce vascular GTN-tolerance or nontolerance. Isolated working hearts obtained from either GTN-tolerant or nontolerant rats were subjected to 10 min coronary occlusion in the presence of 10-7 M GTN or its solvent. 3. GTN improved myocardial function and reduced lactate dehydrogenase (LDH) release during coronary occlusion in both GTN-tolerant and nontolerant hearts. 4. Cardiac NO content significantly increased after GTN administration in both GTN-tolerant and nontolerant hearts as assessed by electron spin resonance. However, cardiac cyclic GMP content measured by radioimmunoassay was not changed by GTN administration. 5. When hearts from both GTN-tolerant and nontolerant rats were subjected to coronary occlusion in the presence of the KATP-blocker glibenclamide (10-7 M), the drug itself did not affect myocardial function and LDH release, however, it abolished the anti-ischaemic effect of GTN. 6. We conclude that GTN opens KATP via a cyclic GMP-independent mechanism, thereby leading to an anti-ischaemic effect in the heart in both GTN-tolerant and nontolerant rats.
Subject(s)
Adenosine Triphosphate/physiology , Cyclic AMP/physiology , Myocardial Ischemia/drug therapy , Nitroglycerin/pharmacology , Potassium Channels/metabolism , Vasodilator Agents/pharmacology , Adenosine Triphosphate/antagonists & inhibitors , Animals , Coronary Circulation/drug effects , Cyclic AMP/metabolism , Glyburide/pharmacology , Heart/drug effects , Heart/physiopathology , Hypoglycemic Agents/pharmacology , L-Lactate Dehydrogenase/metabolism , Male , Myocardial Ischemia/metabolism , Myocardial Ischemia/physiopathology , Nitric Oxide/metabolism , Nitroglycerin/metabolism , Potassium Channel Blockers , Rats , Rats, Wistar , Vasodilator Agents/metabolismABSTRACT
BACKGROUND: The role of NO in the mechanism of preconditioning is not understood. Therefore, we studied the effect of preconditioning and subsequent ischemia/reperfusion on myocardial NO content in the presence of an NO synthase (NOS) inhibitor. METHODS AND RESULTS: Isolated working rat hearts were subjected to preconditioning protocols of 3 intermittent periods of rapid pacing or no-flow ischemia of 5 minutes' duration each followed by a test 30 minutes of global no-flow ischemia and 15 minutes of reperfusion. Test ischemia/reperfusion resulted in a deterioration of myocardial function and a considerable increase in cardiac NO content as assessed by electron spin resonance. Preconditioning improved postischemic myocardial function and markedly decreased test ischemia/reperfusion-induced NO accumulation. In the presence of 4.6 micromol/L N(G)-nitro-L-arginine (LNA), basal cardiac NO content decreased significantly, although test ischemia/reperfusion-induced functional deterioration and NO accumulation were not affected in nonpreconditioned hearts. However, the protective effects of preconditioning on both test ischemia/reperfusion-induced functional depression and NO accumulation were abolished. When 4.6 micromol/L LNA was administered after preconditioning, it failed to block the effect of preconditioning. In the presence of 46 micromol/L LNA, ischemia/reperfusion-induced NO accumulation was significantly decreased and postischemic myocardial function was improved in nonpreconditioned hearts. CONCLUSIONS: Our results show that (1) although NO synthesis by the heart is necessary to trigger classic preconditioning, preconditioning in turn attenuates the accumulation of NO during ischemia/reperfusion, and (2) blockade of ischemia/reperfusion-induced accumulation of cardiac NO by preconditioning or by an appropriate concentration of NOS inhibitor alleviates ischemia/reperfusion injury as demonstrated by enhanced postischemic function.
Subject(s)
Ischemic Preconditioning, Myocardial , Myocardial Ischemia/therapy , Myocardial Reperfusion Injury/prevention & control , Myocardium/metabolism , Nitric Oxide/metabolism , Animals , Electron Spin Resonance Spectroscopy , Enzyme Inhibitors/pharmacology , Male , Nitric Oxide Synthase/antagonists & inhibitors , Nitroarginine/pharmacology , Rats , Rats, WistarABSTRACT
This study was conducted to evaluate the effect of Ginkgo biloba extract (EGb 761) on the nitric oxide (NO) production in relation to the recovery of postischemic cardiac function in isolated working rat hearts. Rats were orally treated with various doses (25, 50, 75, and 100 mg/kg/day) of EGb 761 for 10 days. Hearts were isolated in "working mode" and subjected to 30-min ischemia followed by 120 min of reperfusion. EGb 761 inhibited NO production measured by electron spin-resonance spectroscopy (ESR), and improved the recovery of postischemic cardiac function (coronary flow, aortic flow, left ventricular developed pressure and its first derivative) in the ischemic/reperfused myocardium. Thus in rats treated with 25, 50, 75, and 100 mg/kg/day of EGb 761 and in hearts subjected to 30-min ischemia followed by 120 min of reperfusion, aortic flow was increased from its postischemic drug-free control value of 8.0+/-0.4 to 8.6+/-0.4 ml/min (NS), 17.3+/-0.9 ml/min (p<0.05), 21.5+/-1.1 ml/min (p<0.05), and 23.6+/-1.2 ml/min, respectively. The same recovery in postischemic coronary flow, left ventricular developed pressure, and its first derivative also was observed. In the initial phase of reperfusion, NO production measured by ESR was reduced by 85% in the 75 mg/ kg/day of EGb 761-treated group in comparison with the drug-free ischemic/reperfused hearts. Inducible NO synthase (iNOS) messenger RNA (mRNA) measured by reverse transcription-polymerase chain reaction (RT-PCR) also was reduced by 41 and 58% in the groups treated with 75 and 100 mg/kg/day of EGb 761, respectively. Our findings show that EGb 761 directly acts as an NO scavenger and concomitantly inhibits the expression of iNOS mRNA. Thus, EGb 761 may act as a potent inhibitor of NO production under the condition of ischemia/reperfusion, improving the recovery of postischemic cardiac function.