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1.
Colorectal Dis ; 24(5): 562-576, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35023242

RESUMEN

AIM: Manometry is the best established technique to assess anorectal function in faecal incontinence. By systematic review, pooled prevalences of anal hypotonia/hypocontractility and rectal hypersensitivity/hyposensitivity in male and female patients were determined in controlled studies using anorectal manometry. METHODS: Searches of MEDLINE and Embase were completed. Screening, data extraction and bias assessment were performed by two reviewers. Meta-analysis was performed based on a random effects model with heterogeneity evaluated by I2 . RESULTS: Of 2116 identified records, only 13 studies (2981 faecal incontinence patients; 1028 controls) met the inclusion criteria. Anal tone was evaluated in 10 studies and contractility in 11; rectal sensitivity in five. Only three studies had low risk of bias. Pooled prevalence of anal hypotonia was 44% (95% CI 32-56, I2 = 96.35%) in women and 27% (95% CI 14-40, I2 = 94.12%) in men. The pooled prevalence of anal hypocontractility was 69% (95% CI 57-81; I2 = 98.17%) in women and 36% (95% CI 18-53; I2 = 96.77%) in men. Pooled prevalence of rectal hypersensitivity was 10% (95% CI 4-15; I2 = 80.09%) in women and 4% (95% CI 1-7; I2 = 51.25%) in men, whereas hyposensitivity had a pooled prevalence of 7% (95% CI 5-9; I2 = 0.00%) in women compared to 19% (95% CI 15-23; I2 = 0.00%) in men. CONCLUSIONS: The number of appropriately controlled studies of anorectal manometry is small with fewer still at low risk of bias. Results were subject to gender differences, wide confidence intervals and high heterogeneity indicating the need for international collective effort to harmonize practice and reporting to improve certainty of diagnosis.


Asunto(s)
Incontinencia Fecal , Canal Anal , Incontinencia Fecal/diagnóstico , Femenino , Humanos , Masculino , Manometría , Hipotonía Muscular , Recto
2.
Int J Mol Sci ; 23(4)2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35216312

RESUMEN

Hereditary hypertrophic cardiomyopathy (HCM), due to mutations in sarcomere proteins, occurs in more than 1/500 individuals and is the leading cause of sudden cardiac death in young people. The clinical course exhibits appreciable variability. However, typically, heart morphology and function are normal at birth, with pathological remodeling developing over years to decades, leading to a phenotype characterized by asymmetric ventricular hypertrophy, scattered fibrosis and myofibrillar/cellular disarray with ultimate mechanical heart failure and/or severe arrhythmias. The identity of the primary mutation-induced changes in sarcomere function and how they trigger debilitating remodeling are poorly understood. Support for the importance of mutation-induced hypercontractility, e.g., increased calcium sensitivity and/or increased power output, has been strengthened in recent years. However, other ideas that mutation-induced hypocontractility or non-uniformities with contractile instabilities, instead, constitute primary triggers cannot yet be discarded. Here, we review evidence for and criticism against the mentioned hypotheses. In this process, we find support for previous ideas that inefficient energy usage and a blunted Frank-Starling mechanism have central roles in pathogenesis, although presumably representing effects secondary to the primary mutation-induced changes. While first trying to reconcile apparently diverging evidence for the different hypotheses in one unified model, we also identify key remaining questions and suggest how experimental systems that are built around isolated primarily expressed proteins could be useful.


Asunto(s)
Cardiomiopatía Hipertrófica , Adolescente , Cardiomiopatía Hipertrófica/genética , Cardiomiopatía Hipertrófica/patología , Muerte Súbita Cardíaca/patología , Humanos , Mutación , Fenotipo , Sarcómeros/metabolismo
3.
Can J Physiol Pharmacol ; 92(10): 887-91, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25272092

RESUMEN

Smoothelin-B (SMTL-B) and calponin-1 are important regulators of vascular contraction. SMTL-B contains a calponin-homology domain and is structurally similar to cardiac troponin T. As calponin-1 and troponin T are proteolyzed by intracellular matrix metalloproteinase (MMP)-2 in oxidative stress injury, we hypothesized that SMTL-B is also cleaved by MMP-2 and contributes to lipopolysaccharide (LPS)-induced vascular hypocontractility. Rats received ONO-4817 (an MMP inhibitor) or its vehicle, 2 h prior to being administered lipopolysaccharide (LPS). LPS-induced aorta hypocontractility to potassium chloride or phenylephrine, and reduction of calponin-1 levels, were abolished by ONO-4817 at 6 but not 3 h after LPS. However, the level of SMTL-B was unaltered in LPS aortas and further unaffected by ONO-4817. Despite the importance of SMTL-B in vascular tone, it is not a target of MMP-2 in LPS-induced hypocontractility.


Asunto(s)
Aorta Torácica/efectos de los fármacos , Proteínas del Citoesqueleto/metabolismo , Endotoxemia/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Proteínas Musculares/metabolismo , Músculo Liso Vascular/efectos de los fármacos , Animales , Aorta Torácica/metabolismo , Aorta Torácica/fisiopatología , Proteínas de Unión al Calcio/metabolismo , Simulación por Computador , Endotoxemia/fisiopatología , Humanos , Contracción Isométrica/efectos de los fármacos , Lipopolisacáridos/farmacología , Masculino , Proteínas de Microfilamentos/metabolismo , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiopatología , Ratas Sprague-Dawley , Calponinas
4.
Dis Esophagus ; 27(6): 524-9, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23088758

RESUMEN

In patients with chronic indeterminate Chagas disease, conventional manometry has shown that 25-48% had esophageal motor disorders. Recently, esophageal high-resolution manometry (HRM) has revolutionized the assessment of esophageal motor function. In this study, we performed esophageal HRM in a group of subjects with incidentally positive serological findings for Trypanosoma cruzi. In this prospective observational study, we evaluated subjects who had positive serological tests for Chagas disease detected during a screening evaluation for blood donation. All subjects underwent symptomatic evaluation and esophageal HRM with a 36 solid-state catheter. Esophageal abnormalities were classified using the Chicago classification. Forty-two healthy subjects (38 males) aged 18-61 years (mean age, 40.7 years) were included. When specific symptoms questionnaire was applied, 14 (33%) subjects had esophageal symptoms. Esophageal high-resolution manometry revealed that 28 (66%) of the subjects had an esophageal motility disorder according to the Chicago classification. Most common findings were hypocontractile disorders in 18 subjects (43%) and esophagogastric junction (EGJ) outflow obstruction in 6 (15%). Esophageal high-resolution manometry reveals that up to two thirds of the subjects with an incidental diagnosis of Chagas disease have esophageal abnormalities. This technology increases the detection and allows a more complete assessment of esophageal motor function in subjects infected with T. cruzi even in the early stages of the disease.


Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/complicaciones , Trastornos de la Motilidad Esofágica/diagnóstico , Trastornos de la Motilidad Esofágica/fisiopatología , Manometría , Trypanosoma cruzi/inmunología , Adolescente , Adulto , Enfermedad de Chagas/sangre , Enfermedad de Chagas/diagnóstico , Trastornos de la Motilidad Esofágica/clasificación , Trastornos de la Motilidad Esofágica/parasitología , Esfínter Esofágico Superior/fisiopatología , Femenino , Humanos , Hallazgos Incidentales , Masculino , Persona de Mediana Edad , Presión , Estudios Prospectivos , Adulto Joven
5.
Clin Liver Dis ; 28(3): 369-381, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38945632

RESUMEN

This article reviews the pathophysiology of portal hypertension that includes multiple mechanisms internal and external to the liver. This article starts with a review of literature describing the cellular and molecular mechanisms of portal hypertension, microvascular thrombosis, sinusoidal venous congestion, portal angiogenesis, vascular hypocontractility, and hyperdynamic circulation. Mechanotransduction and the gut-liver axis, which are newer areas of research, are reviewed. Dysfunction of this axis contributes to chronic liver injury, inflammation, fibrosis, and portal hypertension. Sequelae of portal hypertension are discussed in subsequent studies.


Asunto(s)
Hipertensión Portal , Hipertensión Portal/fisiopatología , Hipertensión Portal/etiología , Humanos , Mecanotransducción Celular , Cirrosis Hepática/fisiopatología , Cirrosis Hepática/complicaciones , Hígado/fisiopatología , Hígado/irrigación sanguínea , Neovascularización Patológica/fisiopatología , Circulación Hepática/fisiología , Vena Porta/fisiopatología
6.
Mov Disord Clin Pract ; 10(7): 1074-1081, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37476327

RESUMEN

Introduction: Gastrointestinal dysfunction, particularly constipation, is among the most common non-motor manifestations in Parkinson's Disease (PD). We aimed to identify high-resolution anorectal manometry (HR-ARM) abnormalities in patients with PD using the London Classification. Methods: We conducted a retrospective review of all PD patients at our institution who underwent HR-ARM and balloon expulsion test (BET) for evaluation of constipation between 2015 and 2021. Using age and sex-specific normal values, HR-ARM recordings were re-analyzed and abnormalities were reported using the London Classification. A combination of Wilcoxon rank sum and Fisher's exact test were used. Results: 36 patients (19 women) with median age 71 (interquartile range [IQR]: 69-74) years, were included. Using the London Classification, 7 (19%) patients had anal hypotension, 17 (47%) had anal hypocontractility, and 3 women had combined hypotension and hypocontractility. Anal hypocontractility was significantly more common in women compared to men. Abnormal BET and dyssynergia were noted in 22 (61%) patients, while abnormal BET and poor propulsion were only seen in 2 (5%). Men had significantly more paradoxical anal contraction and higher residual anal pressures during simulated defecation, resulting in more negative recto-anal pressure gradients. Rectal hyposensitivity was seen in nearly one third of PD patients and comparable among men and women. Conclusion: Our data affirms the high prevalence of anorectal disorders in PD. Using the London Classification, abnormal expulsion and dyssynergia and anal hypocontractility were the most common findings in PD. Whether the high prevalence of anal hypocontractility in females is directly related to PD or other confounding factors will require further research.

7.
Low Urin Tract Symptoms ; 14(4): 301-304, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35293147

RESUMEN

CASE: Since the declaration of COVID-19 as a pandemic, other unexpected symptoms related to the infection besides the respiratory system have been reported. Although a few case reports have revealed that adult patients with COVID-19 also complained of urinary frequency and nocturia, the exact pathophysiology is still unclear. In this case series, we present three children aged 14 to 17 years with urodynamically proven lower urinary tract dysfunction (LUTD) following COVID-19. OUTCOME: None of the patients had constipation or bowel disorder before the diagnosis of COVID-19. In addition, neurological examination and related imaging revealed no signs of etiological factors. The median time from diagnosis of COVID-19 infection to the onset of lower urinary tract symptoms was 3 months. Incomplete bladder emptying/urinary retention supported by increased bladder compliance, high post-micturition residual urine volumes, and absence of detrusor pressure increase during the voiding phase in the pressure flow study (acontractile detrusor in two patients and hypocontractile detrusor in one patient) were observed. CONCLUSION: We observed that LUTD (eg, incomplete bladder emptying, urinary retention) can be prominent some time after the diagnosis of COVID-19. Even though psychogenic or neurogenic causes may not be excluded completely, clinicians should be aware of a recent COVID-19 infection in children with sudden-onset LUTD.


Asunto(s)
COVID-19 , Síntomas del Sistema Urinario Inferior , Retención Urinaria , Adulto , COVID-19/complicaciones , Niño , Humanos , Vejiga Urinaria , Retención Urinaria/etiología , Micción/fisiología , Urodinámica
8.
Life Sci ; 284: 119895, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34450166

RESUMEN

AIMS: Dipeptidyl peptidase-4 inhibitor (DPP4i), a new antidiabetic agent, is reported to affect the progression of chronic liver diseases. The study aims to investigate the effects of DPP4i on contractile response, splanchnic hemodynamics, and portal pressure in cirrhotic rats. MATERIALS AND METHODS: A rat model of carbon tetrachloride-induced cirrhosis was used in this study. Sixteen rats with cirrhosis were treated with DDP4i sitagliptin for 5 consecutive days. Portal and systemic pressures and portal blood flow were measured. Mesenteric arterioles were isolated, and concentration-response curves to norepinephrine (NE) were evaluated. The expression of NADPH oxidase (Nox)1, Nox2, Nox4, and soluble epoxide hydrolase (sEH) were detected. Reactive oxygen species (ROS) and epoxyeicosatrienoic acid (EET) levels in mesenteric arteries were also measured. KEY FINDINGS: In cirrhotic rats, sitagliptin significantly reduced portal blood flow and portal pressure without effects on systemic pressure and reversed the decreased response of mesenteric arterioles to NE in an endothelium-dependent manner. Sitagliptin suppressed the increased Nox4 expression and ROS production. In vitro studies showed that Nox4 inhibitor enhanced arteriolar response to NE and reduced hydrogen peroxide (H2O2) level in cirrhotic rats. Sitagliptin also reduced EET levels and increased sEH expression of mesenteric vessels. Pre-incubation with sEH inhibitor in vitro reversed sitagliptin-induced augmentation of response to NE in cirrhotic rats. SIGNIFICANCE: DPP4 inhibition by sitagliptin in vivo has beneficial effects on portal hypertension in cirrhotic rats through normalizing arterial hypocontractility. DDP4 inhibitor may be a novel strategy in the treatment of patients with cirrhosis and portal hypertension.


Asunto(s)
Arterias/fisiopatología , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Hipertensión Portal/complicaciones , Hipertensión Portal/tratamiento farmacológico , Cirrosis Hepática/complicaciones , Cirrosis Hepática/fisiopatología , Vasoconstricción , Animales , Arterias/efectos de los fármacos , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Hemodinámica/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Hipertensión Portal/fisiopatología , Hígado/efectos de los fármacos , Hígado/patología , Cirrosis Hepática/tratamiento farmacológico , Masculino , Arterias Mesentéricas/efectos de los fármacos , Arterias Mesentéricas/fisiopatología , NADPH Oxidasa 4/metabolismo , Norepinefrina/farmacología , Ratas Sprague-Dawley , Fosfato de Sitagliptina/farmacología , Regulación hacia Arriba/efectos de los fármacos , Vasoconstricción/efectos de los fármacos
9.
J Am Heart Assoc ; 10(8): e019922, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33843249

RESUMEN

Background Antenatal intrauterine fetal hypoxia is a common pregnancy complication that has profound adverse effects on an individual's vascular health later in life. Pulmonary arteries are sensitive to hypoxia, but adverse effects of antenatal hypoxia on pulmonary vasoreactivities in the offspring remain unknown. This study aimed to determine the effects and related mechanisms of antenatal hypoxia on pulmonary artery functions in adult male offspring. Methods and Results Pregnant Sprague-Dawley rats were housed in a normoxic or hypoxic (10.5% O2) chamber from gestation days 10 to 20. Male offspring were euthanized at 16 weeks old (adult offspring). Pulmonary arteries were collected for vascular function, electrophysiology, target gene expression, and promoter methylation studies. In pulmonary artery rings, contractions to serotonin hydrochloride, angiotensin II, or phenylephrine were reduced in the antenatal hypoxic offspring, which resulted from inactivated L-type Ca2+ channels. In pulmonary artery smooth muscle cells, the basal whole-cell Ca2+ currents, as well as vasoconstrictor-induced Ca2+ transients were significantly reduced in antenatal hypoxic offspring. In addition, increased promoter methylations within L-type Ca2+ channel subunit alpha1 C were compatible with its reduced expressions. Conclusions This study indicated that antenatal hypoxia programmed long-lasting vascular hypocontractility in the male offspring that is linked to decreases of L-type Ca2+ channel subunit alpha1 C in the pulmonary arteries. Antenatal hypoxia resulted in pulmonary artery adverse outcomes in postnatal offspring, was strongly associated with reprogrammed L-type Ca2+ channel subunit alpha1 C expression via a DNA methylation-mediated epigenetic mechanism, advancing understanding toward the effect of antenatal hypoxia in early life on long-term vascular health.


Asunto(s)
Canales de Calcio Tipo L/genética , Regulación hacia Abajo , Regulación de la Expresión Génica , Hipoxia/genética , Preñez , Arteria Pulmonar/fisiopatología , Vasoconstricción/fisiología , Animales , Presión Sanguínea/fisiología , Canales de Calcio Tipo L/biosíntesis , Células Cultivadas , Femenino , Hipoxia/metabolismo , Hipoxia/fisiopatología , Masculino , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Embarazo , Arteria Pulmonar/metabolismo , Arteria Pulmonar/patología , ARN/genética , Ratas , Ratas Sprague-Dawley
10.
Eur J Pharmacol ; 847: 103-112, 2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30710549

RESUMEN

The effects on the vasculature produced by ethanol withdrawal include both vasodilatation and hypocontractility, although a detailed biochemical understanding of these processes is yet to be accomplished. Here, we sought to investigate some of the mechanisms underlying vascular hypocontractility induced by ethanol withdrawal. Male Wistar rats were treated with increasing doses of 3-9% ethanol (v/v) for 21 days and the impact of ethanol withdrawal on the vascular function was assessed 48 h after immediate ethanol suspension. Endothelium-denuded rat aortic rings showed a reduced contractile response to phenylephrine, angiotensin II, serotonin and KCl after ethanol withdrawal, but the same phenomenon was not observed in endothelium-intact rings. Indomethacin, but not L-NAME, tiron, PEG-catalase and SC560, restored the contractile response to phenylephrine of endothelium-denuded aortas from abstinent rats. Hyporeactivity to phenylephrine induced by ethanol withdrawal was reversed by SC236, a selective cyclooxygenase (COX)-2 inhibitor. Similarly, Ro1138452, a selective prostacyclin IP receptor antagonist, reversed vascular hypocontractility induced by ethanol withdrawal. Increased concentrations of 6-keto-prostaglandin (PG)F1α, a stable product of PGI2, was detected in endothelium-denuded aortas from abstinent rats, and this response was prevented by indomethacin. However, no changes in aortic PGE2 levels were detected after ethanol withdrawal. In situ quantification of hydrogen peroxide (H2O2) and nitric oxide (NO) using fluorescent dyes revealed that ethanol withdrawal decreased the levels of these two compounds in the tunica media. Our studies show that the vascular hypocontractility induced by ethanol withdrawal is independent of the endothelium and it is mediated by PGI2 derived from COX-2.


Asunto(s)
Ciclooxigenasa 2/metabolismo , Epoprostenol/metabolismo , Etanol/efectos adversos , Síndrome de Abstinencia a Sustancias/metabolismo , Animales , Aorta/efectos de los fármacos , Aorta/metabolismo , Compuestos de Bencilo/farmacología , Catalasa/metabolismo , Inhibidores de la Ciclooxigenasa 2/farmacología , Endotelio Vascular/metabolismo , Peróxido de Hidrógeno/farmacología , Imidazoles/farmacología , Indometacina/farmacología , Masculino , Fenilefrina/farmacología , Polietilenglicoles/metabolismo , Pirazoles/farmacología , Ratas , Ratas Wistar , Sulfonamidas/farmacología , Vasoconstricción/efectos de los fármacos , Vasodilatación/efectos de los fármacos
11.
Mol Cell Biol ; 39(11)2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30936247

RESUMEN

Vasodilatory shock in sepsis is caused by the failure of the vasculature to respond to vasopressors, which results in hypotension, multiorgan failure, and ultimately patient death. Recently, it was reported that CPI-17, a key player in the regulation of smooth muscle contraction, was downregulated by lipopolysaccharide (LPS) in mesenteric arteries concordant with vascular hypocontractilty. While Sp1 has been shown to activate CPI-17 transcription, it is unknown whether Sp1 is involved in LPS-induced smooth muscle CPI-17 downregulation. Here we report that tumor necrosis factor (TNF) was critical for LPS-induced smooth muscle CPI-17 downregulation. Mechanistically, we identified two GC boxes as a key TNF response element in the CPI-17 promoter and demonstrated that KLF4 was upregulated by TNF, competed with Sp1 for the binding to the GC boxes in the CPI-17 promoter, and repressed CPI-17 transcription through histone deacetylases (HDACs). Moreover, genetic deletion of TNF or pharmacological inhibition of HDACs protected mice from LPS-induced smooth muscle CPI-17 downregulation, vascular hypocontractility, hypotension, and mortality. In summary, these data provide a novel mechanism of the transcriptional control of CPI-17 in vascular smooth muscle cells under inflammatory conditions and suggest a new potential therapeutic strategy for the treatment of vasodilatory shock in sepsis.


Asunto(s)
Hipotensión/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Lipopolisacáridos/metabolismo , Proteínas Musculares/genética , Músculo Liso Vascular/citología , Factor de Transcripción Sp1/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Regulación hacia Abajo , Técnicas de Inactivación de Genes , Humanos , Hipotensión/metabolismo , Factor 4 Similar a Kruppel , Ratones , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/citología , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Regiones Promotoras Genéticas , Factor de Necrosis Tumoral alfa/genética
12.
Expert Rev Clin Pharmacol ; 11(2): 193-204, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29202586

RESUMEN

INTRODUCTION: Underactive bladder (UAB) is a common cause of lower urinary tract dysfunction which has an increasing incidence with aging. It is characterized as an incompetent detrusor contraction with reduced strength and/or duration to completely empty the bladder. UAB is observed in both men and women. The exact definition, classification, and pathophysiological mechanism responsible for UAB is still debatable, however neurologic, myogenic, and iatrogenic causes are explained. The symptom complex related to UAB includes hesitancy, diminished sensation of bladder filling, a slow urinary stream, increased post-void residue, and etc. Areas covered: We reviewed the current understanding of UAB with special focus on pharmacological treatments and potential pharmacotherapy options particularly in neurological conditions. Also, the definition, etiology, symptoms, diagnosis and management of UAB were discussed in this review. Expert commentary: The underlying mechanism of UAB is not clear yet. Therefore; the lack of efficient pharmacotherapies is evident in such patients. Prior to any decision for pharmacological or surgical interventions, the underlying causes of UAB and detrusor impairment in each patient should be distinguished. Future researches need to address the exact dynamics of detrusor contraction and the muscular and neurological contributors to UAB.


Asunto(s)
Síntomas del Sistema Urinario Inferior/tratamiento farmacológico , Enfermedades de la Vejiga Urinaria/tratamiento farmacológico , Vejiga Urinaria Neurogénica/tratamiento farmacológico , Factores de Edad , Envejecimiento , Animales , Femenino , Humanos , Incidencia , Síntomas del Sistema Urinario Inferior/diagnóstico , Síntomas del Sistema Urinario Inferior/fisiopatología , Masculino , Factores de Riesgo , Enfermedades de la Vejiga Urinaria/diagnóstico , Enfermedades de la Vejiga Urinaria/fisiopatología , Vejiga Urinaria Neurogénica/diagnóstico , Vejiga Urinaria Neurogénica/fisiopatología
13.
Front Physiol ; 8: 1103, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29312005

RESUMEN

Dilated cardiomyopathy amongst children (pediatric cardiomyopathy, pediatric CM) is associated with a high morbidity and mortality. Because little is known about the pathophysiology of pediatric CM, treatment is largely based on adult heart failure therapy. The reason for high morbidity and mortality is largely unknown as well as data on cellular pathomechanisms is limited. Here, we assessed cardiomyocyte contractility and protein expression to define cellular pathomechanisms in pediatric CM. Explanted heart tissue of 11 pediatric CM patients and 18 controls was studied. Contractility was measured in single membrane-permeabilized cardiomyocytes and protein expression was assessed with gel electrophoresis and western blot analysis. We observed increased Ca2+-sensitivity of myofilaments which was due to hypophosphorylation of cardiac troponin I, a feature commonly observed in adult DCM. We also found a significantly reduced maximal force generating capacity of pediatric CM cardiomyocytes, as well as a reduced passive force development over a range of sarcomere lengths. Myofibril density was reduced in pediatric CM compared to controls. Correction of maximal force and passive force for myofibril density normalized forces in pediatric CM cardiomyocytes to control values. This implies that the hypocontractility was caused by the reduction in myofibril density. Unlike in adult DCM we did not find an increase in compliant titin isoform expression in end-stage pediatric CM. The limited ability of pediatric CM patients to maintain myofibril density might have contributed to their early disease onset and severity.

14.
Int J Biol Sci ; 10(4): 386-95, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24719556

RESUMEN

BACKGROUND: Oxidative stress is involved in the hypocontractility of visceral artery to vasoconstrictors and formation of hyperdynamic circulation in cirrhosis with portal hypertension. In the present study, we investigated the effect of reactive oxygen species (ROS) on the mesenteric artery contractility in CCl4-induced cirrhotic rats, and the roles of G protein-coupled receptors (GPCRs) desensitization and RhoA/Rho associated coiled-coil forming protein kinase (ROCK) pathways. METHODS: The mesenteric artery contraction to norepinephrine (NE) was determined by vessel perfusion system following treatments with apocynin, tempol or PEG-catalase. The protein expression of α1 adrenergic receptor, ß-arrestin-2, ROCK-1, moesin and p-moesin was measured by western blot. The interaction between α1 adrenergic receptor and ß-arrestin-2 was assessed by co-immunoprecipitation. RESULTS: Pretreatment with apocynin or PEG-catalase in cirrhotic rats, the hydrogen peroxide level in the mesenteric arteriole was significantly decreased, and the dose-response curve of mesenteric arteriole to NE moved to the left with EC50 decreased. There was no significant change for the expression of α1 adrenergic receptor. However, the protein expression of ß-arrestin-2 and its affinity with α1 adrenergic receptor were significantly decreased. The ROCK-1 activity and anti- Y-27632 inhibition in cirrhotic rats increased significantly with the protein expression unchanged. Such effects were not observed in tempol-treated group. CONCLUSION: The H2O2 decrease in mesenteric artery from rats with cirrhosis resulted in down regulation of the ß-arrestin-2 expression and its binding ability with α1 adrenergic receptor, thereby affecting the agonist-induced ROCK activation and improving the contractile response in blood vessels.


Asunto(s)
Arterias Mesentéricas/efectos de los fármacos , Norepinefrina/farmacología , Amidas , Animales , Arrestinas/genética , Arrestinas/metabolismo , Peróxido de Hidrógeno/metabolismo , Hipertensión Portal/metabolismo , Hipertensión Portal/fisiopatología , Cirrosis Hepática , Masculino , Arterias Mesentéricas/metabolismo , Arterias Mesentéricas/fisiología , Estrés Oxidativo , Piridinas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Arrestina beta 2 , beta-Arrestinas , Quinasas Asociadas a rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo
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