Atrial fibrillation (AF) is associated with severe contractile dysfunction and structural electrophysiological remodeling. Mechanisms responsible for impaired contractility are undefined, current therapies do not address this dysfunction. We have found that myofibrillar creatine kinase (MM-CK), an important controller of myocyte contractility, highly sensitive to oxidative injury, we hypothesized increased stress energetic impairment during AF could contribute Methods Results-- Right atrial...

Cachexia is a syndrome characterized by wasting of skeletal muscle and contributes to nearly one-third all cancer deaths. Cytokines tumor factors mediate suppressing gene products, but exactly which products are targeted these cachectic not well understood. Because their functional relevance architecture, such targets presumed represent myofibrillar proteins, whether proteins regulated in general or selective manner also unclear. Here we demonstrate, using vitro vivo models wasting, that...

Angiotensin II (Ang II), a potent hypertrophic stimulus, causes significant increases in TGFb1 gene expression. However, it is not known whether there causal relationship between increased levels of TGF-β1 and cardiac hypertrophy. Echocardiographic analysis revealed that TGF-β1–deficient mice subjected to chronic subpressor doses Ang had no change left ventricular (LV) mass percent fractional shortening during IItreatment. In contrast, II–treated wild-type showed >20% increase LV impaired...

Cachexia is a syndrome characterized by wasting of skeletal muscle and contributes to nearly one-third all cancer deaths. Cytokines tumor factors mediate suppressing gene products, but exactly which products are targeted these cachectic not well understood. Because their functional relevance architecture, such targets presumed represent myofibrillar proteins, whether proteins regulated in general or selective manner also unclear. Here we demonstrate, using vitro vivo models wasting, that...

Extensive variations exist in the heavy and light chain components of myosin vertebrate striated muscles.In present study, we have characterized a specific contractile property, velocity shortening, protein subunit composition single fibers from adult rabbit soleus muscles.Maximum shortening (Vmax) was measured using slack test method, these same determined an ultrasensitive sodium dodecyl sulfate-polyacrylamide gel electrophoresis system.While most were found to velocities between 0.5 1.0...

Angiotensin II (Ang II), a potent hypertrophic stimulus, causes significant increases in TGFb1 gene expression. However, it is not known whether there causal relationship between increased levels of TGF-β1 and cardiac hypertrophy. Echocardiographic analysis revealed that TGF-β1–deficient mice subjected to chronic subpressor doses Ang had no change left ventricular (LV) mass percent fractional shortening during IItreatment. In contrast, II–treated wild-type showed >20% increase LV impaired...

The goal of this study was to test the hypothesis that relative amounts cardiac myosin heavy chain (MHC) isoforms MHC-α and MHC-β change during development transition heart failure in human myocardium. ventricular atrial samples from fetal (gestational days 47–110) nonfailing failing adult hearts were determined. majority right left contained small (mean < 5% total MHC). There a significant decrease level ventricles between 7 12 wk gestation. Fetal atria expressed predominantly > 95%),...

Hypertrophic cardiomyopathy (HCM) is one of the most common causes sudden cardiac death in young adults and a familial disease at least 60% cases. Causative mutations have been identified several sarcomeric genes, including myosin binding protein C (MYBPC3) gene. Although numerous causative identified, pathogenetic process still poorly understood. A large animal model HCM cat has may be used for additional study. As first spontaneous this disease, feline provides valuable investigators to...

1. The maximal velocity of shortening (Vmax), tension-pCa relationships and the contractile regulatory protein composition were determined in single, chemically skinned fibres from adult rabbit plantaris muscles. 2. Three groups identified based on their compositions. One group had exclusively slow-type myosin heavy chain (MHC) light chains (LC) low velocities. Another mixtures fast-type MHCs LCs intermediate third high 3. low-velocity a mean (+/- S.E.M.) 0.86 +/- 0.03 muscle lengths/s...

The partial agonist activity of a selective androgen receptor modulator (SARM) in the prostate was demonstrated orchidectomized rats. In current study, we characterized full S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide (a structurally related SARM referred to other publications and hereafter as S-4) skeletal muscle, bone, pituitary castrated male Twelve weeks after castration, animals were treated with S-4 (3 or 10 mg/kg),...

Intracoronary thrombolysis during acute myocardial infarction in human beings is associated with rapid release of creatine kinase and improvement the cardiac ejection fraction. To examine phenomenon spontaneous coronary-artery recanalization, we studied MB sequential radionuclide ventriculograms 52 patients transmural infarction. Patients were divided into two groups according to whether (time from base-line peak serum level) was (n = 24) or slow 28). had no significant change global...

Highlights•Development of a mouse model pancreatic adenocarcinoma (PDA)-induced cachexia•Model develops progressive wasting associated with advancing pancreas pathology•Induction cachexia in adult KPP mice models tissue loss PDA cancer patients•Gene ontology cachectic muscles from resembles that patientsSummaryCachexia is syndrome characterized by pronounced skeletal muscle loss. In cancer, increased morbidity and mortality decreased treatment tolerance. Although advances have been made...

In vitro, fibroblast growth factor-2 (FGF2) has been implicated in cardiomyocyte and reexpression of fetal contractile genes, both markers hypertrophy. However, its vivo role cardiac hypertrophy during pressure overload is not well characterized. Mice with or without FGF2 (Fgf2+/+ Fgf2–/–, respectively) were subjected to transverse aortic coarctation (AC). Left ventricular (LV) mass wall thickness assessed by echocardiography preoperatively once a week postoperatively for 10 weeks. LV...

A protocol for sample preparation and gel electrophoresis is described that reliably results in the separation of α- β-isoforms cardiac myosin heavy chain (MHC-α MHC-β) eight mammalian species. The based on a simple, nongradient denaturing gel. magnitude MHC-α MHC-β achieved with this sufficient quantitative determination relative amounts these two isoforms mouse, rat, guinea pig, rabbit, canine, baboon, human myocardial samples. sensitivity detection MHC samples at least as small 1 μg....

Sarcolipin is a novel regulator of cardiac sarcoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) and expressed abundantly in atria. In this study we investigated the physiological significance sarcolipin heart by generating mouse model deficient for sarcolipin. The sarcolipin-null mice do not show any developmental abnormalities or pathology. absence does modify expression level other handling proteins, particular phospholamban, its phosphorylation status. Calcium uptake studies revealed that,...

Significance Chimpanzee “super strength” has been widely reported since the 1920s although a critical review of available data suggests that chimpanzee–human muscular performance differential is only ∼1.5 times. Some hypothesize this reflects underlying differences in muscle mechanics. Here, we present direct measurements chimpanzee skeletal properties comparison with those humans and other terrestrial mammals. Our results show exceeds human maximum dynamic force power output by ∼1.35 This...

Cardiac peroxynitrite and protein nitration are increased during doxorubicin cardiotoxicity, but the intracellular targets functional consequences have not been defined. We investigated distribution of cardiotoxicity in mice. Following vivo cardiac function assessments by echocardiography, tissues were prepared for immunohistochemistry electron microscopy 5 days after (20 mg kg −1 ) or vehicle control. Increased 3‐nitrotyrosine was observed using light treated animals. Immunogold (55,000×)...

The regulation of vertebrate muscle contraction with respect to the role different subunits myosin remains somewhat uncertain. One approach gaining a better understanding molecular basis is study developing which undergoes changes in isozyme composition and contractile properties during normal course maturation. present utilizes single fibers from psoas muscles rabbits at several ages as model system for fast-twitch development. This eliminates inherent problems interpreting results studies...

Skeletal muscles produce transient reactive oxygen species (ROS) in response to intense stimulation, disuse atrophy, heat stress, hypoxia, osmotic stretch and cell receptor activation. The physiological significance is not well understood. Protein phosphatases (PPases) are known be highly sensitive oxidants could contribute many different signalling responses muscle. We tested whether broad categories of PPases inhibited by levels acute oxidant exposure that do result loss contractile...

The hypothesis that ovarian sex hormone deficiency affects cardiac myofilament activation was tested. Chemically skinned ventricular trabeculae and single soleus muscle fibers were prepared from 10- 14-wk ovariectomized control rats. Tension-pCa (−log [Ca 2+ ]) relations of left compared to test whether thin filament proteins are potential sites modulated activation. Trabeculae rats exhibited a significant increase in Ca sensitivity with no change maximal tension-generating ability. In...

The Synchrotron Medical Research Facility (SMERF) at the National Light Source has been completed and is operational for human coronary angiography experiments. imaging system hardware have brought to SMERF from Stanford Radiation Laboratory where prior studies were carried out. consists of a suite rooms end high-field superconducting wiggler X17 beam line classified as an Ambulatory Health Care Facility. Since October 1990 arteries five patients imaged. Continuously improving image quality...

Reiser, Peter J., William O. Kline, and Pal L. Vaghy.Induction of neuronal type nitric oxide synthase in skeletal muscle by chronic electrical stimulation vivo. J. Appl. Physiol. 82(4): 1250–1255, 1997.—Fast-twitch muscles contain more neuronal-type (nNOS) than slow-twitch because nNOS is present only fast (type II) fibers. Chronic vivo tibialis anterior extensor digitorum longus rabbits was used as a method inducing fast-to-slow fiber transformation. We have studied whether an increase...

The effects of prolonged hypokinesia on the contractile properties and myosin isozymes single fibers from synergistic fast-twitch plantaris (PL) slow-twitch soleus (SOL) skeletal muscles adult rats were studied after 28 days hindlimb suspension. There was a 31% increase in mean maximal velocity unloaded shortening (Vmax) among SOL with no change Vmax PL heavy light chain (MHC MLC) composition bundles MHC control suspended examined using sodium dodecyl sulfate-polyacrylamide gel...