RESUMEN
BACKGROUND: Current research on ethanol-induced cardiovascular anomalies has focused on left ventricular (LV) function and blood pressure. To extend this area of research, we sought to determine whether ethanol-induced alterations in the structure and function of the right cardiac ventricle (RV) and pulmonary artery (PA) lead to pulmonary arterial hypertension (PAH). METHODS: Two groups of male Sprague-Dawley rats received a balanced liquid diet containing 5% ethanol (w/v) or a pair-fed isocaloric liquid diet for 8 weeks. Weekly echocardiography was conducted to evaluate cardiopulmonary function, and lung and RV tissues were collected for ex vivo histological and molecular studies. RESULTS: The ethanol-treated rats exhibited: (1) Elevated mean pulmonary arterial pressure and decreased pulmonary artery acceleration time/ejection time; (2) Pulmonary vascular remodeling comprising intrapulmonary artery medial layer thickening; and (3) RV hypertrophy along with increased RV/LV + septum, RV diameter, RV cardiomyocyte cross-sectional area, and LV mass/body weight ratio. These responses were associated with increased lung and RV pro-inflammatory markers, endothelin-1 (ET-1), TNF-α, and IL-6 levels and higher ET-1, ET-1 type A/B receptor ratio, and downregulation of the cytoprotective protein, bone morphogenetic protein receptor 2 (BMPR2), in the lungs. CONCLUSION: These findings show that moderate ethanol-induced cardiopulmonary changes underlie progression to PAH via an upregulated proinflammatory ET1-TNFα-IL6 pathway and suppression of the anti-inflammatory BMPR2.
RESUMEN
AIM: Estrogen (E2) confers cardioprotection in premenopausal women and in models of menopause and its effects, mostly studied in female reproductive organs, vary on a circadian rhythm basis in relation to the circadian clock genes. However, it remains unknown if a similar circadian pattern exists in the female heart in a manner that explains, at least partly, the cardioprotective effect of E2. The aim of the present investigation was to determine if upregulation of the circadian clock Per2 and its regulated heart-specific miRNAs, and redox enzymes contribute to the E2-mediated cardioprotection in ovariectomized rats. MAIN METHODS: Rats were subjected to ovariectomy (OVX) 2-weeks prior to a 2-week E2 treatment. On the last treatment day, hearts were collected every 4 h. for ex-vivo biochemical measurements. In parallel studies, telemetric mean arterial pressure (MAP) was obtained at the tissue collection times. KEY FINDINGS: OVX + E2 rats exhibited lower body weight during daytime and MAP during day and night times, and their hearts exhibited: (1) higher Per2 protein abundance, cardioprotective miRNAs (miRNA1, miRNA133a, miRNA208a, miRNA499), mALDH2, and catalase; (2) lower reactive oxygen species, cardio-detrimental miRNA652, carbonyl, MDA and HO-1 levels. The reciprocal Per2/HO-1 relationship was more evident during the daytime and correlated with the upregulated cardioprotective miRNAs in OVX + E2 rats. Finally, cardiac Per2, heart-specific miRNAs and reactive oxygen species levels and redox enzymes activities were similar in normal female and OVX + E2 rats. SIGNIFICANCE: Enhancement of cardiac Per2, redox enzymes and heart-specific miRNAs likely contribute to E2-mediated mitigation of cardiac oxidative stress in OVX rats.
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Relojes Circadianos , MicroARNs , Humanos , Ratas , Femenino , Animales , Especies Reactivas de Oxígeno/metabolismo , Relojes Circadianos/genética , MicroARNs/genética , MicroARNs/metabolismo , Estrógenos/farmacología , Estrógenos/metabolismo , Estrés Oxidativo , Ovariectomía , Estradiol , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismoRESUMEN
Activation of the rostral ventrolateral medulla (RVLM) cannabinoid receptor-1 (CB1R) causes neuronal nitric oxide synthase (nNOS)-dependent increases in sympathetic activity, blood pressure (BP) and heart rate (HR) in male rats. However, it remains unknown if the CB1R-mediated neurochemical and cardiovascular responses are influenced by the ovarian sex hormones, particularly estrogen (E2). Therefore, we studied the effects of intra-RVLM CB1R activation (WIN 55,212-2) on BP and HR in conscious female rats under the following hormonal states: (1) highest E2 level (proestrus sham-operated, SO); (2) E2-deprivation (ovariectomized, OVX); (3) OVX with E2 replacement (OVXE2). Intra-RVLM WIN55,212-2 elicited dose (100-400 pmol) dependent pressor and tachycardic responses, in OVX rats, which replicated the reported responses in male rats. However, in SO and OVXE2 rats, the CB1R-mediated pressor response was attenuated and the tachycardic response reverted to bradycardic response. The neurochemical findings suggested a key role for the upregulated RVLM sympathoexcitatory molecules phosphorated protein kinase B, phosphorated nNOS and reactive oxygen species in the exaggerated CB1R-mediated BP and HR responses in OVX rats, and an E2-dependent dampening of these responses. The intra-RVLM WIN55212-2-evoked cardiovascular and neurochemical responses were CB1R-mediated because they were attenuated by prior CB1R blockade (AM251). Our findings suggest that attenuation of RVLM neuroexcitation and oxidative stress underlies the protection conferred by E2, in female rats, against the CB1R-mediated adverse cardiovascular effects.
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Estrógenos , Bulbo Raquídeo , Receptor Cannabinoide CB1 , Vasoconstrictores , Animales , Benzoxazinas/farmacología , Presión Sanguínea/efectos de los fármacos , Estrógenos/metabolismo , Estrógenos/farmacología , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Masculino , Bulbo Raquídeo/efectos de los fármacos , Bulbo Raquídeo/metabolismo , Morfolinas/farmacología , Naftalenos/farmacología , Ratas , Ratas Sprague-Dawley , Receptor Cannabinoide CB1/metabolismo , Vasoconstrictores/farmacologíaRESUMEN
Brain orexin system hyperactivity contributes to neurogenic hypertension. We previously reported upregulated neuronal kinin B1 receptor (B1R) expression in hypertension. However, the role of central B1R activation on the orexin system in neurogenic hypertension has not been examined. We hypothesized that kinin B1R contributes to hypertension via upregulation of brain orexin-arginine vasopressin signaling. We utilized deoxycorticosterone acetate (DOCA)-salt hypertension model in wild-type (WT) and B1R knockout (B1RKO) mice. In WT mice, DOCA-salt-treatment increased gene and protein expression of orexin A, orexin receptor 1, and orexin receptor 2 in the hypothalamic paraventricular nucleus and these effects were attenuated in B1RKO mice. Furthermore, DOCA-salt- treatment increased plasma arginine vasopressin levels in WT mice, but not in B1RKO mice. Cultured primary hypothalamic neurons expressed orexin A and orexin receptor 1. B1R specific agonist (LDABK) stimulation of primary neurons increased B1R protein expression, which was abrogated by B1R selective antagonist R715 but not by the dual orexin receptor antagonist, ACT 462206, suggesting that B1R is upstream of the orexin system. These data provide novel evidence that B1R blockade blunts orexin hyperactivity and constitutes a potential therapeutic target for the treatment of salt-sensitive hypertension.
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Regulación de la Expresión Génica , Hipertensión/metabolismo , Hipotálamo/metabolismo , Neuronas/metabolismo , Orexinas/metabolismo , Receptor de Bradiquinina B1/biosíntesis , Animales , Modelos Animales de Enfermedad , Hipertensión/inducido químicamente , Hipertensión/tratamiento farmacológico , Hipertensión/genética , Ratones , Ratones Noqueados , Orexinas/genética , Receptor de Bradiquinina B1/genéticaRESUMEN
Oxidation of tetrahydrobiopterin (BH4), a cofactor of nitric oxide synthase (NOS), by reactive oxidative species (ROS), leads to NOS uncoupling and superoxide production instead of NO. Further, oxidative stress plays a major role in ethanol-evoked cardiac dysfunction in proestrus female rats, and acute ethanol administration reduces brain BH4 level. Therefore, we discerned the unknown role of BH4 in ethanol-evoked cardiac dysfunction by pharmacologically increasing BH4 levels or inhibiting its effect in proestrus female rats. Acute ethanol (1.5 g/kg, i.v, 30 min) caused myocardial dysfunction (lowered dP/dtmax and LVDP) and hypotension, along with increases in myocardial: (i) levels of NO, ROS and malondialdehyde (MDA), (ii) activities of catalase, ALDH2 and NADPH oxidase (Nox), and (iii) phosphorylation of eNOS, nNOS. Further, ethanol suppressed myocardial arginase and superoxide dismutase (SOD) activities and enhanced eNOS uncoupling. While ethanol had no effect on cardiac BH4 levels, BH4 (19 mg/kg, i.v) supplementation paradoxically caused cardiac oxidative stress, but mitigated the cardiac dysfunction/hypotension and most of the adverse molecular responses caused by ethanol. Equally important, the BH4 inhibitor DAHP (1 g/kg, i.p) exacerbated the adverse molecular and cardiovascular effects caused by ethanol. Our pharmacological studies support a protective role for the NOS co-factor BH4 against ethanol-evoked cardiac dysfunction and hypotension in female rats.
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Biopterinas/análogos & derivados , Cardiomiopatías/tratamiento farmacológico , Etanol/efectos adversos , Corazón/efectos de los fármacos , Animales , Biopterinas/antagonistas & inhibidores , Biopterinas/farmacología , Biopterinas/uso terapéutico , Cardiomiopatías/inducido químicamente , Cardiomiopatías/patología , Modelos Animales de Enfermedad , Femenino , Humanos , Miocardio/patología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Especies Reactivas de Oxígeno/metabolismo , Azúcares Ácidos/farmacologíaRESUMEN
In the present investigation, we tested the hypothesis that suppression of the phospho-extracellular signal regulated kinase (pERK1/2)-nuclear factor kappa (NFκ)-B signaling, subsequent to tumor necrosis factor-α (TNF-α) inhibition, underlies thalidomide (TLM) mediated neuroprotection. Male Wistar rats (250-280 g) were divided into five groups: (1) sham; (2) negative control receiving TLM (5µg/1µl/site) and 3 groups of ischemia-reperfusion (IR) injury rats pretreated with: (3) vehicle (DMSO 100%); (4) TLM (5µg/1µl/site) or (5) PD98059 (0.16µg/1µl/site). IR rats were subjected to occlusion of both common carotid arteries for 45 min followed by reperfusion for 24 h. Drugs and/or vehicles were administered by unilateral intrahippocampal injection after removal of the carotid occlusion and at the beginning of the reperfusion period. IR rats exhibited significant infarct size, histopathological damage, memory impairment, motor incoordination and hyperactivity. Unilateral intra-hippocampal TLM ameliorated these behavioral deficits along with the following ex vivo hippocampal effects: (i) abrogation of the IR-evoked elevations in hippocampal TNF-α, pERK1/2, NFκB, BDNF, iNOS contents and (ii) partial restoration of the reduced anti-inflammatory cytokine IL-10 and p-nNOS S852. These neurochemical effects, which were replicated by the pERK1/2 inhibitor PD98059, likely underlie the reductions in c-Fos and caspase-3 levels as well as the anti-apoptotic effect of TLM in the IR model. These results suggest a crucial anti-inflammatory role for pERK1/2 inhibition in the salutary neuronal and behavioral effects of TLM in a model of brain IR injury.
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Antiinflamatorios/farmacología , Isquemia Encefálica/tratamiento farmacológico , Hipocampo/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , FN-kappa B/metabolismo , Fármacos Neuroprotectores/farmacología , Daño por Reperfusión/prevención & control , Talidomida/farmacología , Animales , Isquemia Encefálica/enzimología , Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Modelos Animales de Enfermedad , Hipocampo/enzimología , Hipocampo/patología , Hipocampo/fisiopatología , Masculino , Memoria/efectos de los fármacos , Actividad Motora/efectos de los fármacos , Fosforilación , Ratas Wistar , Daño por Reperfusión/enzimología , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND AND AIMS: The molecular mechanism of the adverse effects of ethanol on diurnal cardiovascular regulation remains unknown. In separate studies, the cardiac circadian rhythm protein period-2 (PER2) confers cardioprotection and, in other organs, PER2 interaction with the ethanol-metabolizing enzyme CYP2E1 underlies, via heme oxygenase-1 (HO-1) upregulation, tissue injury/dysfunction. Here, we hypothesized that suppressed PER2 expression and elevated CYP2E1/HO-1 levels in the heart underlie the disrupted diurnal cardiovascular rhythm/function in alcohol-fed normotensive rats. METHODS: In ethanol-fed (5%, w/v; 8 weeks) or isocaloric liquid diet-fed male rats, diurnal changes in blood pressure (BP), heart rate (HR), HR vagal variability index, root mean square of successive beat-to-beat differences in beat-interval duration (rMSSD), and cardiac function were measured by radiotelemetry and echocardiography followed by ex vivo molecular studies. RESULTS: Radiotelemetry findings showed ethanol-evoked reductions in BP (during the dark cycle), rMSSD (during both cycles), and in diurnal differences in BP and rMSSD. Echocardiography findings revealed significant (p < 0.05) reductions in ejection fraction and fractional shortening (weeks 4-6) in the absence of cardiac remodeling (collagen content). Hearts of ethanol-fed rats exhibited higher (p < 0.05) CYP2E1 activity (50%) and HO-1 expression (63%), along with reduction (p < 0.05) in PER2 levels (29%), compared with the hearts of isocaloric diet-fed control rats. CONCLUSIONS: Our novel findings implicate upregulations of CYP2E1/HO-1 and downregulation of the circadian rhythm cardioprotective protein PER2, in the heart, in the chronic deleterious diurnal cardiovascular effects of alcohol in male rats.
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Ritmo Circadiano , Citocromo P-450 CYP2E1 , Etanol/efectos adversos , Corazón/efectos de los fármacos , Proteínas Circadianas Period/metabolismo , Animales , Presión Sanguínea , Citocromo P-450 CYP2E1/metabolismo , Masculino , Miocardio/enzimología , Carbonilación Proteica , Ratas , Ratas Sprague-DawleyRESUMEN
AIMS: To investigate if autonomic dysregulation is exacerbated in female rats, subjected to diabetes mellitus (DM), via a paradoxical estrogen (E2)-evoked provocation of neuroinflammation/injury of the hypothalamic paraventricular nucleus (PVN). MAIN METHODS: We measured cardiac autonomic function and conducted subsequent PVN neurochemical studies, in DM rats, and their respective controls, divided as follows: male, sham operated (SO), ovariectomized (OVX), and OVX with E2 supplementation (OVX/E2). KEY FINDINGS: Autonomic dysregulation, expressed as sympathetic dominance (higher low frequency, LF, band), only occurred in DM E2-replete (SO and OVX/E2) rats, and was associated with higher neuronal activity (c-Fos) and higher levels of TNFα and phosphorylated death associated protein kinase-3 (p-DAPK3) in the PVN. These proinflammatory molecules likely contributed to the heightened PVN oxidative stress, injury and apoptosis. The PVN of these E2-replete DM rats also exhibited upregulations of estrogen receptors, ERα and ERß, and proinflammatory adenosine A1 and A2a receptors. SIGNIFICANCE: The E2-dependent autonomic dysregulation likely predisposes DM female rats and women to hypersensitivity to cardiac dysfunction. Further, upregulations of proinflammatory mediators including adenosine A1 and A2 receptors, TNFα and DAPK3, conceivably explain the paradoxical hypersensitivity of DM females to PVN inflammation/injury and the subsequent autonomic dysregulation in the presence of E2.
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Sistema Nervioso Autónomo/fisiopatología , Diabetes Mellitus Experimental/complicaciones , Estrógenos/farmacología , Cardiopatías/fisiopatología , Hipotálamo/fisiopatología , Inflamación/patología , Animales , Apoptosis , Proteínas Quinasas Asociadas a Muerte Celular/metabolismo , Complicaciones de la Diabetes/fisiopatología , Femenino , Corazón/efectos de los fármacos , Frecuencia Cardíaca , Masculino , Estrés Oxidativo , Núcleo Hipotalámico Paraventricular/metabolismo , Fosforilación , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismo , Factores Sexuales , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia ArribaRESUMEN
ur preclinical findings replicated women's hypersensitivity to type-2 diabetes mellitus (T2DM)-evoked cardiac dysfunction along with demonstrating estrogen (E2)-dependent disruption of the cardiac adiponectin (APN)-connexin43 (Cx43) signaling. Whether the latter molecular anomaly underlies this women's cardiovascular health problem remains unknown. We hypothesized that restoration of the disrupted APN-Cx43 signaling alleviates this sex/E2-dependent cardiac dysfunction in diabetic female rats. To test this hypothesis, we administered the adiponectin receptor 1 (AdipoR1) agonist AdipoRon (30 mg/kg/d for 10 days) to female sham operated (SO) and ovariectomized (OVX) rats, which exhibited and lacked the T2DM left ventricular (LV) dysfunction, respectively, when fed high-fat diet and received low dose streptozotocin regimen; nondiabetic control SO and OVX rats received control diet and vehicle for streptozotocin. In T2DM SO rats, LV dysfunction, AdipoRon mitigated: (1) LV hypertrophy, (2) reductions in fractional shortening, LV developed pressure, dP/dtmax, dP/dtmin, and Tau. In LV tissues of the same rats, AdipoRon reversed reduction in Cx43 and elevations in TNFα, heme-oxygenase 1 (HO-1), and circulating cardiovascular risk factor asymmetric dimethylarginine. The findings also revealed ovarian hormones independent effects of AdipoRon, which included dampening of the pro-oxidant enzyme HO-1. These novel findings yield new insight into a causal role for compromised APN-Cx43 signaling in the E2-dependent hypersensitivity to T2DM-evoked cardiac inflammation and dysfunction. Equally important, the findings identify restoration of Cx43 signaling as a viable therapeutic modality for alleviating this women's cardiovascular health-related problem.
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Adiponectina/metabolismo , Conexina 43/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Cardiomiopatías Diabéticas/prevención & control , Hipertrofia Ventricular Izquierda/prevención & control , Piperidinas/farmacología , Disfunción Ventricular Izquierda/prevención & control , Función Ventricular Izquierda/efectos de los fármacos , Animales , Arginina/análogos & derivados , Arginina/metabolismo , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Cardiomiopatías Diabéticas/etiología , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/fisiopatología , Estradiol/metabolismo , Receptor alfa de Estrógeno/metabolismo , Femenino , Hemo Oxigenasa (Desciclizante)/metabolismo , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/metabolismo , Hipertrofia Ventricular Izquierda/fisiopatología , Ovariectomía , Ratas Wistar , Receptores de Adiponectina/agonistas , Receptores de Adiponectina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/metabolismo , Disfunción Ventricular Izquierda/fisiopatología , Remodelación Ventricular/efectos de los fármacosRESUMEN
BACKGROUND: Aldehyde dehydrogenase 2 (ALDH2) protects against alcohol-evoked cardiac dysfunction in male rodents, but its role in the estrogen (E2 )-dependent hypersensitivity of female rats to alcohol-evoked myocardial oxidative stress and dysfunction is not known. METHODS: We addressed this question by studying the effect of cyanamide (ALDH2 inhibitor) on cardiac function, blood pressure, alcohol-metabolizing enzyme (alcohol dehydrogenase, cytochrome P450 2E1, catalase, and ALDH2) activities, and cardiac redox status (reactive oxygen species, ROS; malondialdehyde, MDA) in the absence or presence of ethanol (EtOH) in female sham-operated (SO) and ovariectomized (OVX) rats. RESULTS: Cyanamide attenuated the EtOH-evoked myocardial dysfunction (reduced dP/dtmax and LVDP) in SO rats. EtOH, cyanamide, or their combination did not alter dP/dtmax or LVDP in OVX rats. Cyanamide induced cardiac oxidative stress and abrogated the subsequent alcohol-evoked increases in ROS and MDA levels in SO rats. Neither EtOH nor cyanamide influenced ROS or MDA levels in OVX rats. Importantly, cyanamide exaggerated EtOH-evoked hypotension in SO and uncovered this hypotensive response in OVX rats, which implicates ALDH2 in the vasodilating effect of EtOH. CONCLUSIONS: Contrary to our hypothesis, cyanamide attenuated the E2 -dependent cardiac dysfunction caused by alcohol, likely by preconditioning the heart to oxidative stress, while exacerbating the vasodilating effect of alcohol. The latter might predispose to syncope when cyanamide and alcohol are combined in females.
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Aldehído Deshidrogenasa Mitocondrial/antagonistas & inhibidores , Inhibidores Enzimáticos/uso terapéutico , Etanol/toxicidad , Cardiopatías/inducido químicamente , Cardiopatías/tratamiento farmacológico , Hipotensión/inducido químicamente , Aldehído Deshidrogenasa Mitocondrial/metabolismo , Animales , Cianamida/farmacología , Cianamida/uso terapéutico , Inhibidores Enzimáticos/farmacología , Etanol/administración & dosificación , Femenino , Cardiopatías/enzimología , Hipotensión/metabolismo , Ovariectomía , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.
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Acetaldehído/farmacología , Fármacos del Sistema Nervioso Autónomo/farmacología , Etanol/metabolismo , Corazón/efectos de los fármacos , Animales , Femenino , Masculino , Miocardio , Estrés Oxidativo , Ratas , Ratas Endogámicas SHRRESUMEN
The reasons for the higher severity of type 2 diabetes (T2DM)-associated cardiomyopathy in women, despite their inherent estrogen (E2)-dependent cardioprotection, remain unknown. We hypothesized that the reliance of the healthy females' hearts on augmented adiponectin (APN)-connexin 43 (Cx43) signaling becomes paradoxically detrimental when disrupted by T2DM in an E2-dependent manner. We tested this hypothesis in high-fat, low- dose streptozotocin diabetic rats and their controls with the following designations: 1) sham-operated (SO), 2) ovariectomized (OVX), 3) ovariectomized with E2 supplementation (OVX + E2), and 4) male. E2-replete (SO or OVX + E2) diabetic rats exhibited higher mortality and greater increases in left ventricular (LV) mass and reduced LV developed pressure, LV contractility, and fractional shortening but preserved ejection fraction. Further, compared with respective nondiabetic counterparts, the hearts of these E2-replete diabetic rats exhibited greater upregulation of cardiac estrogen receptor α and reductions in Cx43 expression and in the phosphorylation levels of the survival molecules extracellular regulating kinases 1/2 and phosphorylated AKT (pAKT). Whereas serum APN was reduced, independent of sex and ovarian hormone status in all DM rats, cardiac APN was most drastically reduced in DM SO rats. The present translational findings are the first to implicate ovarian hormones/E2 in the exacerbated myocardial dysfunction in female diabetic subjects and to suggest a pivotal role for malfunctioning cardiac APN-Cx43 signaling in this sex/E2-specific clinical problem.
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Adiponectina/sangre , Cardiomiopatías/sangre , Conexina 43/sangre , Diabetes Mellitus Experimental/sangre , Estrógenos/sangre , Caracteres Sexuales , Animales , Cardiomiopatías/diagnóstico por imagen , Diabetes Mellitus Experimental/diagnóstico por imagen , Estradiol/sangre , Femenino , Masculino , Ratas , Ratas WistarRESUMEN
We recently demonstrated a fundamental role for cystathionine-γ lyase (CSE)-derived hydrogen sulfide (H2S) in the cardioprotective effect of the centrally acting drug moxonidine in diabetic rats. Whether a downregulated CSE/H2S system in the rostral ventrolateral medulla (RVLM) underlies neuronal oxidative stress and sympathoexcitation in diabetes has not been investigated. Along with addressing this question, we tested the hypothesis that moxonidine prevents the diabetes-evoked neurochemical effects by restoring CSE/H2S function within its major site of action, the RVLM. Ex vivo studies were performed on RVLM tissues of streptozotocin (55 mg/kg, i.p.) diabetic rats treated daily for 3 weeks with moxonidine (2 or 6 mg/kg; gavage), H2S donor sodium hydrosulfide (NaHS) (3.4 mg/kg, i.p.), CSE inhibitor DL-propargylglycine (DLP) (37.5 mg/kg, i.p.), a combination of DLP with moxonidine, or their vehicle. Moxonidine alleviated RVLM oxidative stress, neuronal injury, and increased tyrosine hydroxylase immunoreactivity (sympathoexcitation) by restoring CSE expression/activity as well as heme oxygenase-1 (HO-1) expression. A pivotal role for H2S in moxonidine-evoked neuroprotection is supported by the following: 1) NaHS replicated the moxonidine-evoked neuroprotection, and the restoration of RVLM HO-1 expression in diabetic rats; and 2) DLP abolished moxonidine-evoked neuroprotection in diabetic rats, and caused RVLM neurotoxicity, reminiscent of a diabetes-evoked neuronal phenotype, in healthy rats. These findings suggest a novel role for RVLM CSE/H2S/HO-1 in moxonidine-evoked neuroprotection and sympathoinhibition, and as a therapeutic target for developing new drugs for alleviating diabetes-evoked RVLM neurotoxicity and cardiovascular anomalies.
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Cistationina gamma-Liasa/metabolismo , Diabetes Mellitus Experimental/metabolismo , Imidazoles/farmacología , Bulbo Raquídeo/efectos de los fármacos , Bulbo Raquídeo/enzimología , Fármacos Neuroprotectores/farmacología , Sistema Nervioso Simpático/efectos de los fármacos , Animales , Diabetes Mellitus Experimental/enzimología , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Experimental/fisiopatología , Hemo-Oxigenasa 1/metabolismo , Sulfuro de Hidrógeno/metabolismo , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Sistema Nervioso Simpático/fisiopatologíaRESUMEN
Chronic GPR18 activation by its agonist abnormal cannabidiol (trans-4-[3-methyl-6-(1-methylethenyl)-2-cyclohexen-1-yl]-5-pentyl-1,3-benzenediol; abn-cbd) improves myocardial redox status and function in healthy rats. Here, we investigated the ability of abn-cbd to alleviate diabetes-evoked cardiovascular pathology and the contribution of GPR18 to this effect. Four weeks after diabetes induction by streptozotocin (STZ, 55mg/kg; i.p), male Wistar rats received abn-cbd, the GPR18 antagonist (1,3-dimethoxy-5-methyl-2-[(1R,6R)-3-methyl-6-(1-methylethenyl)-2-,cyclohexen-1-yl]benzene;O-1918), their combination (100µg/kg/day, i.p, each) or their vehicle for 2 weeks. Abn-cbd had no effect on diabetes-evoked cardiac hypertrophy or impaired glycemic control (hyperglycemia and hypoinsulinemia), but alleviated the associated reductions in left ventricular (LV) contractility (dP/dtmax) and relaxation (dP/dtmin) indices, and the increases in LV end diastolic pressure (LVEDP) and cardiac vagal dominance. Abn-cbd also reversed myocardial oxidative stress by restoring circulating and cardiac nitric oxide (NO) and adiponectin (ADN) levels and enhancing GPR18 expression and phosphorylation of Akt, ERK1/2 and eNOS in diabetic rats' hearts. Concurrent GPR18 blockade (O-1918) abrogated all favorable effects of abn-cbd in diabetic rats. Collectively, the current findings present evidence for abn-cbd alleviation of diabetes-evoked cardiovascular anomalies likely via GPR18 dependent restoration of cardiac adiponectin-Akt-eNOS signaling and the diminution of myocardial oxidative stress.
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Cardiotónicos/farmacología , Diabetes Mellitus Experimental/tratamiento farmacológico , Resorcinoles/farmacología , Adiponectina/sangre , Animales , Glucemia/metabolismo , Cardiotónicos/uso terapéutico , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Regulación de la Expresión Génica/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Masculino , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Miocardio/metabolismo , Óxido Nítrico/sangre , Óxido Nítrico Sintasa de Tipo III/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Receptores de Cannabinoides/metabolismo , Resorcinoles/uso terapéutico , Disfunción Ventricular Izquierda/tratamiento farmacológicoRESUMEN
BACKGROUND: Ethanol (EtOH)-evoked oxidative stress, which contributes to myocardial dysfunction in proestrus rats, is mediated by increases in NADPH oxidase (Nox) activity, malondialdehyde (MDA), and ERK1/2 phosphorylation. Whether these biochemical responses, which are triggered by alcohol-derived acetaldehyde in noncardiac tissues, occur in proestrus rats' hearts remains unknown. Therefore, we elucidated the roles of alcohol dehydrogenase (ADH), cytochrome P4502E1 (CYP2E1), and catalase, which catalyze alcohol oxidation to acetaldehyde, in these alcohol-evoked biochemical and hemodynamic responses in proestrus rats. METHODS: Conscious proestrus rats prepared for measurements of left ventricular (LV) function and blood pressure (BP) received EtOH (1.5 g/kg, intravenous [i.v.] infusion over 30 minutes) or saline 30 minutes after an ADH and CYP2E1 inhibitor, 4-methylpyrazole (4-MP) (82 mg/kg, intraperitoneal), a catalase inhibitor, 3-AT (0.5 g/kg, i.v.), their combination, or vehicle. LV function and BP were monitored for additional 60 minutes after EtOH or saline infusion before collecting the hearts for ex vivo measurements of LV reactive oxygen species (ROS), Nox activity, MDA, and ERK1/2 phosphorylation. RESULTS: EtOH reduced LV function (dP/dtmax and LV developed pressure) and BP, and increased cardiac Nox activity, ROS and MDA levels, and ERK1/2 phosphorylation. Either inhibitor partially, and their combination significantly, attenuated these responses despite the substantially higher blood EtOH level, and the increased cardiac oxidative stress and reduced BP caused by 3-AT alone or with 4-MP. The inhibitors reduced cardiac MDA level and reversed EtOH effect on cardiac and plasma MDA. CONCLUSIONS: EtOH oxidative metabolism plays a pivotal role in the EtOH-evoked LV oxidative stress and dysfunction in proestrus rats. Notably, catalase inhibition (3-AT) caused cardiac oxidative stress and hypotension.
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Cardiomiopatías/inducido químicamente , Cardiomiopatías/prevención & control , Catalasa/antagonistas & inhibidores , Depresores del Sistema Nervioso Central/toxicidad , Inhibidores Enzimáticos/uso terapéutico , Etanol/toxicidad , Neurofisinas/antagonistas & inhibidores , Estrés Oxidativo/efectos de los fármacos , Precursores de Proteínas/antagonistas & inhibidores , Vasopresinas/antagonistas & inhibidores , Amitrol (Herbicida)/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Cardiomiopatías/fisiopatología , Depresores del Sistema Nervioso Central/antagonistas & inhibidores , Depresores del Sistema Nervioso Central/sangre , Etanol/antagonistas & inhibidores , Etanol/sangre , Femenino , Fomepizol , Proestro , Pirazoles/uso terapéutico , Ratas , Ratas Sprague-Dawley , Función Ventricular IzquierdaRESUMEN
AIMS: Little is known about the role of subcellular trafficking of estrogen receptor (ER) subtypes in the acute estrogen (E2)-mediated alleviation of oxidative stress. We tested the hypothesis that ERα migration to the cardiac myocyte membrane mediates the acute E2-dependent improvement of cellular redox status. MAIN METHODS: Myocardial distribution of subcellular ERα, ERß and G-protein coupled estrogen receptor (GPER) was determined in proestrus sham-operated (SO) and in ovariectomized (OVX) rats, acutely treated with E2 (1µg/kg) or a selective ERα (PPT), ERß (DPN) or GPER (G1) agonist (10µg/kg), by immunofluorescence and Western blot. We measured ROS and malondialdehyde (MDA) levels, and catalase and superoxide dismutase (SOD) activities to evaluate myocardial antioxidant/redox status. KEY FINDINGS: Compared with SO, OVX rats exhibited higher myocardial ROS and MDA levels, reduced catalase and SOD activities, along with diminished ERα, and enhanced ERß and GPER, localization at cardiomyocyte membrane. Acute E2 or an ERα (PPT), but not ERß (DPN) or GPER (G1), agonist reversed these responses in OVX rats and resulted in higher ERα/ERß and ERα/GPER ratios at the cardiomyocytes membrane. PPT or DPN enhanced myocardial Akt phosphorylation. We present the first evidence that preferential aggregation of ERα at the cardiomyocytes plasma membrane is ERα-dependent, and underlies E2-mediated reduction in oxidative stress, at least partly, via the enhancements of myocardial catalase and SOD activities in OVX rats. SIGNIFICANCE: The findings highlight ERα agonists as potential therapeutics for restoring the myocardial redox status following E2 depletion in postmenopausal women.
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Receptor alfa de Estrógeno/metabolismo , Estrógenos/metabolismo , Miocardio/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Animales , Receptor beta de Estrógeno/metabolismo , Femenino , Miocitos Cardíacos/metabolismo , Ovariectomía , Ratas , Ratas Sprague-Dawley , Receptores Acoplados a Proteínas G/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
In this review we discuss the sex/estrogen-specific modulation of cardiovascular function and responses to current therapeutics. We discuss how anatomical differences such as a smaller kidney size, and lower glomerular filtration rate in females, reduce the clearance and increase the toxicity of some drugs in females. Other important sex differences include the dampening effect of estrogen on central sympathetic and renin angiotensin systems. Further, we discuss how a shift in myocardial redox status leads to paradoxical transformation of estrogen into a pro-inflammatory hormone. Finally, the review, along with cited recent publications, identify some areas that need further investigation to advance our understanding of the sex differences in cardiovascular disease outcomes to help develop female specific interventions for these anomalies.
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Fármacos Cardiovasculares/farmacología , Fármacos Cardiovasculares/uso terapéutico , Enfermedades Cardiovasculares/tratamiento farmacológico , Estrógenos/metabolismo , Animales , Sistema Cardiovascular/efectos de los fármacos , Sistema Cardiovascular/metabolismo , Humanos , Caracteres SexualesRESUMEN
Recent findings linked the inhibition in the neuromodulator peptide endothelin-1 (ET-1) level to the high glucose-evoked neurotoxicity. However, definitive neuroprotective role for ET-1 and the major neuronal ET (ET-3) against high glucose-evoked toxicity and the implicated neurochemical responses triggered by their ET-A and ET-B receptors remain unknown. Here, we tested the hypothesis that ET-B activation alleviates high glucose-evoked oxidative stress and cell death. High glucose (100 mM for 48 hours)-evoked cell death was associated with elevation in reactive oxygen species, inhibition of catalase activity, and a paradoxical upregulation of hemeoxygenase-1 expression along with ET-A and ET-B receptors were downregulated and upregulated, respectively. ET-1 or ET-3, in concentrations that had no effect on PC12 cell viability in normal glucose medium, alleviated all high glucose-evoked neurochemical responses, except for the reduction in ET-A receptor expression. Prior (4 hours) incubation with a selective ET-A (BQ123) or ET-B (BQ788) receptor blocker abrogated the neuroprotection conferred by ET-1 or ET-3. However, the ET-B receptor played a greater role because BQ788 abrogated the favorable ET-1- or ET-3-mediated reversal of the ERK1/2 phosphorylation and the inhibition in catalase activity caused by high glucose. These findings suggest that endothelin exerts ET-B receptor-dependent favorable redox and neuroprotective effects against high glucose-evoked oxidative damage and neurotoxicity.