• Characterization of the myocardial contractile proteins has been undertaken in an attempt to define biochemical mechanisms responsible for the physiological dissimilarities between cardiac and skeletal muscle. These functional differences include the lesser tension generated by cardiac muscle,' different actions of inotropic agents,' and the relative slowness of onset of the active state of c...

• Characterization of the myocardial contractile proteins has been undertaken in an attempt to define biochemical mechanisms responsible for the physiological dissimilarities between cardiac and skeletal muscle. These functional differences include the lesser tension generated by cardiac muscle,' different actions of inotropic agents,' and the relative slowness of onset of the active state of c...

BACKGROUND Duchenne muscular dystrophy is a fatal cardiac and skeletal muscle disease resulting from mutations in the dystrophin gene. We have previously demonstrated that a dystrophin-associated protein, sarcospan (SSPN), ameliorated Duchenne muscular dystrophy skeletal muscle degeneration by activating compensatory pathways that regulate muscle cell adhesion (laminin-binding) to the extracell...

• Numerous studies of cardiac muscle mechanics have produced contradictory conclusions. The present paper discusses a few salient points about cardiac muscle mechanics, but it is not a critical review of the literature such as that recently published by Jewell and Blinks (1). An analysis of ventricular contraction is also presented; we hope that it will stimulate fresh thought about the relatio...

Troponin T (TnT) is an essential protein in the Ca2+ regulatory system of striated of muscle. Three fiber type-specific TnT genes have evolved in higher vertebrates to encode cardiac, slow and fast skeletal muscle TnT isoforms. To understand the functional significance of TnT isoforms, we studied the effects of acidosis on the contractility of transgenic mouse cardiac muscle that expresses fast...

THAT changes in ionic gradients affect contractility and excitability has been shown in skeletal muscle,' cardiac muscle' ° and nerve." The reduction of external sodium causes reduction and eventual loss of excitability in nerve and skeletal muscle, supposedly because depolarization is due to the entry of sodium into the cell. The precise effect of alterations in external sodium on contractilit...

Skeletal muscle derived stem cells (MDSCs) transplanted into injured myocardium can differentiate into fast skeletal muscle specific myosin heavy chain (sk-fMHC) and cardiac specific troponin-I (cTn-I) positive cells sustaining recipient myocardial function. We have recently found that MDSCs differentiate into a cardiomyocyte phenotype within a three-dimensional gel bioreactor. It is generally ...

Intracardiac transplantation of undifferentiated skeletal muscle cells (myoblasts) has emerged as a promising therapy for myocardial infarct repair and is already undergoing clinical trials. The fact that cells originating from skeletal muscle have different electrophysiological properties than cardiomyocytes, however, may considerably limit the success of this therapy and, in addition, cause s...