-
Kevin J French, Robert W Coatney,
Jon P Renninger,
Catherine X Hu,
Tracy L Gales,
Shufang Zhao,
Laura M Storck,
Charles B Davis,
Jeanelle McSurdy-Freed,
Emile Chen,
Kendall S Frazier
[show abstract]
[hide abstract]
ABSTRACT: Several multikinase angiogenesis inhibitors demonstrate mitochondrial and/or cardiovascular toxicity, suggesting an on-target pharmacologic effect. To evaluate whether cardiotoxicity is directly related to vascular endothelial growth factor receptor inhibition, we investigated the effects of sunitinib, sorafenib, and pazopanib on myocardial function and structure. We used a rat model to assess myocardial effects of the inhibitors concurrently exposed to the cardiac stressor dobutamine. Echocardiographic abnormalities including premature ventricular contractions, decreases in heart rate, circumferential strain, and radial and circumferential strain rates were noted with sorafenib, but not with sunitinib or pazopanib. Ultrastructural analysis of ventricular cardiomyocytes by transmission electron microscopy revealed mitochondrial swelling, dense deposits, and matrix cavitation in rats given sunitinib and disrupted mitochondrial cristae in rats given sorafenib, but there were no effects with pazopanib. Effects on neonatal rat cardiomyocyte cultures were assessed, which identified decreases in mitochondrial membrane potential with sunitinib treatment, but not with sorafenib or pazopanib. Intracellular adenosine triphosphate depletion was observed with sunitinib and sorafenib, but not pazopanib. Our results show that cardiotoxicity is not necessarily related to a pharmacologic classwide effect of vascular endothelial growth factor receptor inhibition, and the rat myocardial structural and functional changes identified in this study may be instead a result of inhibition of other kinase pathways, the mechanism of which may be associated with mitochondrial toxicity.
Toxicologic Pathology 08/2010; 38(5):691-702. · 1.91 Impact Factor
-
Robert N Willette,
Marianne E Eybye,
Alan R Olzinski,
David J Behm,
Nambi Aiyar,
Kristeen Maniscalco,
Ross G Bentley, Robert W Coatney,
Shufang Zhao,
Timothy D Westfall,
Chris P Doe
[show abstract]
[hide abstract]
ABSTRACT: The evidence is compelling for a role of inflammation in cardiovascular diseases; however, the chronic use of anti-inflammatory drugs for these indications has been disappointing. The recent study compares the effects of two anti-inflammatory agents [cyclooxygenase 2 (COX2) and p38 inhibitors] in a model of cardiovascular disease. The vascular, renal, and cardiac effects of 4-(4-methylsulfonylphenyl)-3-phenyl-5H-furan-2-one (rofecoxib; a COX2 inhibitor) and 6-{5-[(cyclopropylamino)carbonyl]-3-fluoro-2-methylphenyl}-N-(2,2-dimethylpropyl)-3-pyridinecarboxamide [GSK-AHAB, a selective p38 mitogen-activated protein kinase (MAPK) inhibitor], were examined in the spontaneously hypertensive stroke-prone rat (SHR-SP). In SHR-SPs receiving a salt-fat diet (SFD), chronic treatment with GSK-AHAB significantly and dose-dependently improved survival, endothelial-dependent and -independent vascular relaxation, and indices of renal function, and it attenuated dyslipidemia, hypertension, cardiac remodeling, plasma renin activity (PRA), aldosterone, and interleukin-1beta (IL-1beta). In contrast, chronic treatment with a COX2-selective dose of rofecoxib exaggerated the harmful effects of the SFD, i.e., increasing vascular and renal dysfunction, dyslipidemia, hypertension, cardiac hypertrophy, PRA, aldosterone, and IL-1beta. The protective effects of a p38 MAPK inhibitor are clearly distinct from the deleterious effects of a selective COX2 inhibitor in the SHR-SP and suggest that anti-inflammatory agents can have differential effects in cardiovascular disease. The results also suggest a method for evaluating long-term cardiovascular efficacy and safety.
Journal of Pharmacology and Experimental Therapeutics 07/2009; 330(3):964-70. · 3.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Urodynamics have been traditionally recorded in anesthetized or conscious animals implanted with a bladder catheter that is used to artificially fill the bladder while measuring intravesicular bladder pressure. Anesthesia alters the urodynamics and in the conscious state this methodology requires that the dogs be tethered/restrained, which evokes stress and limits the period of continuous urodynamic assessment. A more physiological and chronic method of evaluating pharmacological responses on urodynamics is necessary.
Adult female beagle dogs were surgically instrumented with radiotelemetry transmitters enabling urodynamic/hemodynamic recordings. Telemetered urodynamics were compared to those measured in anesthetized dogs receiving bladder infusion of saline. The response to diuresis with furosemide (Intervet, Millsboro, Delaware) and the M3 selective antimuscarinic darifenacin (Matrix Laboratories, Hyderabad, India) were evaluated.
Saline infused, anesthetized dogs demonstrated lower peak micturition pressure and higher threshold pressure than conscious, freely moving telemetered dogs. In telemetered dogs a single dose of furosemide increased voiding frequency and average urine volume per void. Darifenacin decreased peak voiding pressure without affecting voiding frequency.
Telemetry provides the potential to significantly decrease animal use while enabling the continuous monitoring of urodynamics under more physiological conditions without tethering or artificial filling. In addition, this new model facilitates evaluation of the chronic efficacy of new urological therapies.
The Journal of urology 02/2009; 181(3):1444-51. · 4.02 Impact Factor
-
Alexandra Hicks,
Gerald P McCafferty,
Erin Riedel,
Nambi Aiyar,
Mark Pullen,
Christopher Evans,
Trudy D Luce, Robert W Coatney,
Gian C Rivera,
Timothy D Westfall,
J Paul Hieble
[show abstract]
[hide abstract]
ABSTRACT: Functional studies have demonstrated that adrenoceptor agonist-evoked relaxation is mediated primarily by beta3-adrenergic receptors (ARs) in human bladder. Thus, the use of selective beta3-AR agonists in the pharmacological treatment of overactive bladder is being explored. The present studies investigated the effects of a novel selective beta3-AR agonist, (R)-3'-[[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]amino]ethyl]amino]-[1,1'-biphenyl]-3-carboxylic acid (GW427353; solabegron) on bladder function in the dog using in vitro and in vivo techniques. GW427353 stimulated cAMP accumulation in Chinese hamster ovary cells expressing the human beta3-AR, with an EC50 value of 22 +/- 6 nM and an intrinsic activity 90% of isoproterenol. At concentrations of 10,000 nM, GW427353 produced a minimal response in cells expressing either beta1-ARs or beta2-ARs (maximum response <10% of that to isoproterenol). In dog isolated bladder strips, GW427353 evoked relaxation that was attenuated by the nonselective beta-AR antagonist bupranolol and 1-(2-ethylphenoxy)-3-[[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]-(2S)-2-propanol (SR59230A) (reported to have beta3-AR antagonist activity). The relaxation was unaffected by atenolol, a selective beta1-AR antagonist, or (+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol (ICI 118551), a selective beta2-AR antagonist. GW427353 increased the volume required to evoke micturition in the anesthetized dog following acetic acid-evoked bladder irritation, without affecting the ability of the bladder to void. GW427353-evoked effects on bladder parameters in vivo were inhibited by bupranolol. The present study demonstrates that selective activation of beta3-AR with GW427353 evokes bladder relaxation and facilitates bladder storage mechanisms in the dog.
Journal of Pharmacology and Experimental Therapeutics 11/2007; 323(1):202-9. · 3.83 Impact Factor
-
Weike Bao,
David J Behm,
Sandhya S Nerurkar,
Zhaohui Ao,
Ross Bentley,
Rosanna C Mirabile,
Douglas G Johns,
Tina N Woods,
Christopher P A Doe, Robert W Coatney,
Jason F Ohlstein,
Stephen A Douglas,
Robert N Willette,
Tian-Li Yue
[show abstract]
[hide abstract]
ABSTRACT: Angiotensin II (Ang II) activates p38 mitogen-activated protein kinase (p38 MAPK) and increases reactive oxygen species (ROS), but the nature of the relationship in vivo is not fully understood. We assess the effect of SB239063AN, a highly selective, orally active, p38 MAPK inhibitor, on Ang II-dependent hypertension, target-organ damage and ROS production. Sprague-Dawley rats and MAPKAP kinase-2 knockout mice were infused with Ang II. Ang II infusion increased the levels of phosphorylated p38 MAPK in the heart and aorta. Production of superoxide anion and expression of NAD(P)H oxidase subunit gp91 in the aorta were increased 4- and 5-fold, respectively. In addition, Ang II infusion led to endothelial dysfunction, progressive and sustained hypertension, and cardiac hypertrophy. Treatment with SB239063AN (800 ppm in the diet) significantly attenuated the levels of phosphorylated p38 MAPK in the heart and aorta, reduced superoxide anion generation by 57% (P < 0.01), markedly suppressed gp91 mRNA expression, prevented endothelial dysfunction, and blunted both the hypertension and cardiac hypertrophy. Ang II-dependent hypertension was also significantly attenuated in MAPKAP kinase-2 knockout mice. The results suggest that Ang II induced hypertension, organ damage, and ROS production are possibly mediated by p38 MAPK and inhibition of p38 MAPK may offer a therapeutic approach for cardiovascular disease.
Journal of Cardiovascular Pharmacology 07/2007; 49(6):362-8. · 2.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Histological studies have provided evidence that carvedilol can prevent cardiac hypertrophy in spontaneously hypertensive-stroke prone rats (SP) fed a high-fat and -salt diet. However, the effects of carvedilol on cardiac function have not been studied in these animals. In addition, the ability of carvedilol to reverse established cardiac hypertrophy and dysfunction under these conditions remains to be determined. Here we have evaluated the ability of carvedilol to prevent and reverse cardiac hypertrophy and progressive dysfunction using echocardiography.
Two echocardiology studies were conducted to determine the effects of carvedilol treatment on cardiac hypertrophy and dysfunction. In the first prevention study, four groups of rats were evaluated. SP were fed a high-fat (24.5% in food) and high-salt (1% in water) diet (SFD) without (SP-SFD control group) or with carvedilol (SP-SFD carvedilol group; carvedilol concentration 2,400 parts per million) for 18 weeks. Carvedilol was administered in the food at an optimum concentration (i.e. known to provide clinically relevant blood concentrations and reduce cardiac hypertrophy determined from previous studies). In addition, SP and WKY rats were fed a normal diet (SP normal diet group and WKY normal diet group). These groups are known to not develop the same significant cardiac hypertrophy and dysfunction within this limited time of study, and provided two more normal control groups for comparison. In the second reversal study, one group of SP was fed SFD for 12 weeks (SP-SFD pretreatment period) to induce cardiac hypertrophy. Carvedilol (2,400 parts per million) was then added to the diet for an additional 6 weeks (SP-SFD carvedilol treatment period).
In the first prevention study, carvedilol prolonged longevity (p < 0.05) and prevented left-ventricular hypertrophy and dysfunction (p < 0.05; SP-SFD control vs. SP-SFD carvedilol group). M-mode-measured and -calculated parameters demonstrated that carvedilol treatment in the SP-SFD carvedilol group prevented increases in left-ventricular wall thickness (p < 0.05) and decreases in diastolic chamber diameter and volume, stroke volume, ejection fraction and cardiac output (all p < 0.05) that occurred in the SP-SFD control group. Further, cardiac measurements in the SP-SFD carvedilol group were normalized to levels similar to those in the SP and WKY normal diet groups. All SFD-fed groups exhibited similar, significantly elevated blood pressure during the study. In the second reversal study, carvedilol treatment for 6 weeks reversed the cardiac hypertrophy and dysfunction that developed in SP-fed SFD for 12 weeks prior to carvedilol intervention. Under these conditions, carvedilol improved/normalized left-ventricular wall thickness, diastolic ventricular-chamber diameter and volume, stroke volume, ejection fraction and cardiac output (all p < 0.05).
These data indicate that carvedilol provides protection from and facilitates reversal of progressive cardiac remodeling and dysfunction in this SP-SFD model of cardiac hypertrophy/heart failure. Since these effects occurred in the absence of effects on blood pressure, other known actions of carvedilol, especially its antioxidant activity, for example, may explain this significant cardiac protection. In addition, research using this SP-SFD model of cardiac hypertrophy/end-organ injury appears to translate well to human cardiovascular disease.
Pharmacology 01/2007; 80(2-3):166-76. · 1.79 Impact Factor
-
Alan R Olzinski,
Tara A McCafferty,
Shufang Q Zhao,
David J Behm,
Marianne E Eybye,
Kristeen Maniscalco,
Ross Bentley,
Kendall S Frazier,
Chavon M Milliner,
Rosanna C Mirabile, Robert W Coatney,
Robert N Willette
[show abstract]
[hide abstract]
ABSTRACT: Evidence suggests important relationships among chronic inflammatory processes, endothelial dysfunction, hypertension and target organ damage. The present study examined the effects of chronic treatment with an anti-inflammatory p38 mitogen-activated protein kinase (MAPK) inhibitor (SB-239063AN) in the N(omega)-nitro-l-arginine methyl ester-treated spontaneously hypertensive rat (SHR+l-NAME) model of severe hypertension and accelerated target organ damage.
SHRs were divided into control (n=16), l-NAME (n=26) and l-NAME+SB-239063AN (n=24) groups. l-NAME was delivered by the drinking water ad lib (50 mg/L) and SB-239063AN was administered by the diet (1200 ppm) for 4 weeks. Arterial blood pressure (telemetry) and target organ damage (kidney, heart, and vasculature) were examined.
The introduction of l-NAME to the drinking water elicited a severe/sustained increase in blood pressure and significant morbidity and mortality. Chronic treatment with SB-239063AN had no effect on the initial blood pressure response (7 days) to l-NAME but attenuated subsequent increases in diastolic blood pressure and significantly reduced morbidity/mortality (42% vs. 5%, p<0.002). Renal dysfunction characterized by increased total protein and albumin excretion was apparent within 2 weeks in the SHR+l-NAME groups. Treatment with SB-239063AN delayed the onset of proteinuria and albuminuria. SB-239063AN treatment also significantly reduced l-NAME-induced interstitial fibrosis in the kidney and restrictive concentric hypertrophy in the left ventricle (end-diastolic volume 0.24+/-0.05 vs. 0.41+/-0.05 ml; p<0.05). Endothelial dysfunction was also not altered by SB-239063AN treatment (Rmax 49+/-6% vs. 45+/-9%).
The results demonstrate that morbidity/mortality and accelerated target organ damage induced by inhibition of nitric oxide synthase in SHR was attenuated by treatment with a selective p38 MAPK inhibitor, SB-239063AN. The organ protection observed in the heart and kidney was not associated with preservation of endothelial function.
Cardiovascular Research 05/2005; 66(1):170-8. · 6.06 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this investigation was to determine whether angiotensin II receptor (AII1R) antagonism interferes with cardiac monocyte chemoattractant protein-1 (MCP-1) expression in hypertrophic cardiomyopathy and failure.
We studied the effects of the AII1R antagonist eprosartan on MCP-1 expression, and on the recruitment of macrophages into the myocardium in a model of cardiac hypertrophy and morbidity/mortality.
Stroke-prone spontaneously hypertensive rats fed a high-salt, high-fat diet (SFD) developed heart failure characterized by left ventricular (LV) hypertrophy/pathology and hypocontractility. These rats received either normal diet, SFD, or SFD with the daily administration of 30 mg/kg eprosartan for 28 weeks. LV function and wall thickness was assessed by echocardiography, MCP-1 expression was measured by TaqMan real-time polymerase chain reaction, enzyme-linked immunosorbent assay and immunohistochemistry, and macrophage infiltration into the LV was determined by microscopy.
Eprosartan reduced the rate of morbidity/mortality (P = 0.001), LV MCP-1 mRNA (P < 0.05) and protein expression (P < 0.01), and LV macrophage infiltration (P < 0.01), while preserving ventricular function (P < 0.05). Eprosartan also produced a moderate (16%; P < 0.05) decrease in blood pressure.
These data demonstrate that AII1R antagonism in an animal model of hypertensive heart disease reduces MCP-1 expression in the myocardium that results in reduced macrophage recruitment. These effects parallel the preservation of LV systolic function and the reduction in cardiac remodeling/disease progression and reduced morbidity/mortality. Suppression of MCP-1 expression might explain in part the beneficial effects of AII1R antagonism in this model.
Journal of Hypertension 03/2004; 22(3):583-92. · 4.02 Impact Factor
-
David J Behm,
Stephen M Harrison,
Zhaohui Ao,
Kristeen Maniscalco,
Susan J Pickering,
Evelyn V Grau,
Tina N Woods, Robert W Coatney,
Christopher P A Doe,
Robert N Willette,
Douglas G Johns,
Stephen A Douglas
[show abstract]
[hide abstract]
ABSTRACT: 1 Urotensin-II (U-II) is among the most potent mammalian vasoconstrictors identified and may play a role in the aetiology of essential hypertension. Currently, only one mouse U-II receptor (UT) gene has been cloned. It is postulated that this protein is solely responsible for mediating U-II-induced vasoconstriction. 2 This hypothesis has been investigated in the present study, which assessed basal haemodynamics and vascular reactivity to hU-II in wild-type (UT((+/+))) and UT receptor knockout (UT((-/-))) mice. 3 Basal left ventricular end-diastolic and end-systolic volumes/pressures, stroke volumes, mean arterial blood pressures, heart rates, cardiac outputs and ejection fractions in UT((+/+)) mice and in UT((-/-)) mice were similar. 4 Relative to UT((+/+)) mouse isolated thoracic aorta, where hU-II was a potent spasmogen (pEC(50)=8.26+/-0.08) that evoked relatively little vasoconstriction (17+/-2% 60 mM KCl), vessels isolated from UT((-/-)) mice did not respond to hU-II. However, in contrast, the superior mesenteric artery isolated from both the genotypes did not contract in the presence of hU-II. Reactivity to unrelated vasoconstrictors (phenylephrine, endothelin-1, KCl) and endothelium-dependent/independent vasodilator agents (carbachol, sodium nitroprusside) was similar in the aorta and superior mesenteric arteries isolated from both the genotypes. 5 The present study is the first to directly link hU-II-induced vasoconstriction with the UT receptor. Deletion of the UT receptor gene results in loss of hU-II contractile action with no 'nonspecific' alterations in vascular reactivity. However, as might be predicted based on the limited contractile efficacy recorded in vitro, the contribution that hU-II and its receptor make to basal systemic haemodynamics appears to be negligible in this species.
British Journal of Pharmacology 06/2003; 139(2):464-72. · 4.41 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Evidence suggests that endothelin receptor antagonists may have therapeutic potential for the chronic treatment of heart failure. In the current study, the effects of an orally active mixed endothelin-A/endothelin-B (ET A /ET B ) receptor antagonist (enrasentan) were assessed in a model of cardiac hypertrophy and dysfunction (spontaneously hypertensive stroke prone rats) maintained on a high-salt/high-fat diet. Echocardiography was used to quantify cardiac performance and left ventricular dimensions. Enrasentan (1,200 and 2,400 parts per million in the high-salt/high-fat diet) had no significant effects on body weight and systolic blood pressure. However, increases in heart rate were not observed in the enrasentan-treated groups at 12 weeks (p < 0.05). Enrasentan-treated groups exhibited significantly improved survival (90-95% vs. 30% [control rats] at 18 weeks; p < 0.001). Enrasentan treatments also increased stroke volume (at 8, 12, and 16 weeks) and cardiac index (at 8 and 16 weeks) 33-50% and 45-63%, respectively. Enrasentan treatments reduced the relative wall thickness (14-27% at 8 and 12 weeks), ratio of left ventricular mass to body weight (20% at 12 weeks), and ratio of terminal heart weight to body weight (16-23%, p < 0.05). Finally, circulating aldosterone concentration (54-57%) and proANF fragment (33%) were reduced in enrasentan-treated groups (54-57% and 33%, respectively). Mixed ET A /ET B receptor antagonism improves cardiac performance and attenuates ventricular remodeling and premature mortality in an aggressive hypertension model.
Journal of Cardiovascular Pharmacology 09/2001; 38(4):606-617. · 2.29 Impact Factor
