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Left Ventricular Developed Pressure (leave + ventricular_developed_pressure)
Selected AbstractsRanolazine Attenuates Palmitoyl- l -carnitine-induced Mechanical and Metabolic Derangement in the Isolated, Perfused Rat HeartJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2000KAZUYASU MARUYAMA The effect of ranolazine, a novel anti-ischaemic drug that stimulates the activity of pyruvate dehydrogenase, on palmitoyl- l -carnitine-induced mechanical dysfunction and metabolic derangement in isolated perfused rat hearts has been studied and compared with the effect of dichloroacetate, an activator of pyruvate dehydrogenase. Rat hearts paced electrically were perfused aerobically at constant flow by the Langendorff technique. Palmitoyl- l -carnitine (4 ,m) increased left ventricular end-diastolic pressure and reduced left ventricular developed pressure (i.e. induced mechanical dysfunction); it also reduced tissue levels of adenosine triphosphate and increased tissue levels of adenosine monophosphate (i.e. induced metabolic derangement). These functional and metabolic alterations induced by palmitoyl- l -carnitine were attenuated by ranolazine (5, 10, and 20 ,m) in a concentration-dependent manner. In contrast, dichloroacetate (1 and 10 mm) did not attenuate palmitoyl- l -carnitine-induced mechanical and metabolic derangement. In the normal (palmitoyl- l -carnitine-untreated) heart, however, ranolazine did not modify mechanical function and energy metabolism. These results suggest that ranolazine attenuates palmitoyl- l -carnitine-induced mechanical and metabolic derangement in the rat heart, and that the beneficial action of ranolazine is not because of the energy-sparing effect or activation of pyruvate dehydrogenase. [source] Procyanidins Produce Significant Attenuation of Doxorubicin-Induced Cardiotoxicity via Suppression of Oxidative StressBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2009Wei Li The major side effect of doxorubicin is oxidative injury-related cardiotoxicity, which has dramatically hindered its usage. Procyanidins from grape seeds are potent free radical scavengers that have been shown to protect against anthracycline-induced cardiotoxicity. In the present study, we tested whether procyanidins would prevent the doxorubicin-induced cardiotoxicity in rats. Rats were intraperitoneally treated with doxorubicin at a cumulative dose of 15 mg/kg with and without pre-administration of procyanidins. Our data showed that doxorubicin led to cardiac function deterioration, myocardial injury and increased oxidative stress in cardiac tissues. The cardiac function deterioration by doxorubicin included increased QT-interval and ST-interval in electrocardiograph (ECG) and decreased left ventricular developed pressure. Doxorubicin-induced myocardial injury was shown by the increased creatine kinase, alanine aminotransferase and aspartate aminotransferase in serum as well as in myocardial lesions. Pretreatment with procyanidin (150 mg/kg daily) effectively hindered the adverse effects of doxorubicin, such as myocardial injury and impaired heart function. Procyanidin pretreatment attenuated cytoplasmic vacuolization, increased left ventricular developed pressure and improved the ECG. The cardioprotective effect of procyanidin corresponded to the decrease of lipid peroxidation and the increase of cardiac antioxidant potency in doxorubicin-treated rats that were also given procyanidin. An in vitro cytotoxic study showed that procyanidins did not attenuate the antineoplastic activity of doxorubicin to A549 adenocarcinoma cells. All the above lines of evidence suggest that procyanidins protect cardiomyocytes from doxorubicin-induced cardiotoxicity via suppression of oxidative stress. [source] Cardioprotection from ischemia-reperfusion injury due to Ras-GTPase inhibition is attenuated by glibenclamide in the globally ischemic heartCELL BIOCHEMISTRY AND FUNCTION, Issue 4 2007Ibrahim Al-Rashdan Abstract The present study was designed to see if acute local inhibition of Ras-GTPase before or after ischemia (during perfusion) would produce protection against ischemia and reperfusion (I/R)-induced cardiac dysfunction. The effect of glibenclamide, an inhibitor of cardiac mitochondrial ATP-sensitive potassium (mitoKATP) channels, on Ras-GTPase-mediated cardioprotection was also studied. A 40,min episode of global ischemia followed by a 30,min reperfusion in perfused rat hearts produced significantly impaired cardiac function, measured as left ventricular developed pressure (Pmax) and left ventricular end-diastolic pressure (LVEDP). Perfusion with Ras-GTPase inhibitor FPT III before I/R [FPT(pre)], significantly enhanced cardiac recovery in terms of left ventricular contractility. Pmax was significantly higher at the end of 30,min reperfusion in FPT(pre)-treated hearts compared to pre-conditioned hearts. However, the degree of improvement in left ventricular contractility was significantly less when FPT III was given only after ischemia during reperfusion [FPT(post)]. Combination treatment with FPT III and glibenclamide before I/R resulted in significant reduction of FPT III-mediated cardioprotection. These data suggest that activation of Ras-GTPase signaling pathways during ischemia are critical in the development of left ventricular dysfunction and that opening of mitoKATP channels, at least in part, contributes to cardioprotection produced by Ras-GTPase inhibition. Copyright © 2006 John Wiley & Sons, Ltd. [source] Endothelin-1-mediated coronary vasoconstriction deteriorates myocardial depression in hearts isolated from lipopolysaccharide,treated rats: Interaction with nitric oxideCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2004Jie Tu Summary 1.,The aim of the present study was to evaluate the contribution of disturbance of coronary perfusion to myocardial depression in hearts isolated from lipopolysaccharide (LPS)-treated rats and to investigate the involvement of endothelin (ET)-1 and nitric oxide (NO). 2.,Rats were treated with LPS (10 mg/kg, i.p.) and, 4 h later, plasma ET-1 concentrations were measured by radioimmunoassay and hearts were excised for perfusion at a constant perfusion flow. The selective ETA receptor antagonist BQ-123, in the absence or presence of aminoguanidine, a specific inhibitor of inducible NO synthase, was given 15 min before LPS challenge. Coronary perfusion pressure (CPP) and measures of myocardial contractile function were recorded. 3.,In hearts isolated from LPS-treated rats, there was a marked increase in CPP that was abolished by pretreatment with BQ-123. In parallel, an increase in plasma ET-1 concentrations was seen in these rats. Lipopolysaccharide also induced decreases in left ventricular developed pressure (LVDP), the product of LVDP and heart rate and maximal rate of rise/fall of left ventricular pressure (+/, dP/dtmax). Single treatment with BQ-123 or aminoguanidine attenuated LPS-induced myocardial depression. However, when these two drugs were given simultaneously, myocardial depression elicited by LPS was blocked significantly. 4.,Endothelin-1-mediated coronary vasoconstriction, together with NO, contributes to myocardial depression in hearts isolated from LPS-treated rats. [source] | ||||||||||