Dissociation between factors resulting in hypertrophy and changes in myosin isoenzyme population of the pressure-loaded rat heart

Rupp, Heinz; Popova, N; Jacob, R.

doi:10.1007/978-3-642-85326-5_5

Cited by 6 publications

(2 citation statements)

References 19 publications

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“…This reduction is due to a shift in the ventricular myosin isoenzymes toward the "slow" isoforms V2 and V3 (11,23,24,26) and is paralleled by a decrease in ventricular myosin Ca + § activated ATPase activity (22,26) and in oxygen consumption (1,19,20). Vmax in the hypertrophied myocardium correlates with the percentage of myosin alpha-heavy chains (19,27).…”

Section: Introductionmentioning

confidence: 96%

Comparison between isomyosin pattern and contractility of right ventricular myocytes isolated from rats with right cardiac hypertrophy

et al. 1989

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The contractile properties of single rat cardiac cells isolated from normal and hypertrophied right ventricles have been investigated. These have been correlated with the isoenzyme composition of the whole ventricle. Right cardiac hypertrophy was induced by injecting rats with monocrotaline, an alkaloid which induces severe pulmonary hypertension. Ca2+ ATPase activity and myosin alpha-chain percentage were decreased in the hypertrophied right ventricle as compared with that of control rats. The contraction amplitude and speed of shortening of the isolated cells were measured using an inverted microscope, video camera, and edge detection device. Cells from the hypertrophied ventricle showed a significantly decreased contraction amplitude and speed of shortening in maximally activating concentrations of isoprenaline. A statistically significant correlation existed between myosin alpha-chain percentage and both contraction amplitude and speed of shortening in maximum isoprenaline. This was true when all cells studied were included, as well as within the hypertrophy group. A similar, although not always statistically significant, correlation was observed when cells were maximally activated with calcium. These results suggest that changes in isomyosin pattern that occur in cardiac hypertrophy produce alterations in contraction amplitude and speed of shortening which can be detected in single cells isolated from the hypertrophied ventricles. Isolated cells appear to give responses representative of the function of the whole heart.

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Section: Introductionmentioning

confidence: 96%

Comparison between isomyosin pattern and contractility of right ventricular myocytes isolated from rats with right cardiac hypertrophy

et al. 1989

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“…Two types of cardiac myosin heavy chains, designated as HC~ and HC~ have been described in the cardiac muscle cells. They show characteristic patterns in their distribution according to the species (24,48), fiber types (12,21,39), and the physiologic (5,33,50) and pathophysiologic state (7,11,18,29,38,55), respectively. The changes in the expression of the isomyosins may prove to be an important means for regulation of cardiac muscle contractility and are thought to play a role in the pathophysiology of cardiac hypertrophy.…”

Section: Introductionmentioning

confidence: 99%

Atrial and ventricular myosins from human hearts II. Isoenzyme distribution after myocardial infarction

1987

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Human atrial and ventricular myosins were prepared from autopsy specimens from subjects with coronary heart disease. Cardiac myosin light chain isotypes were resolved using two-dimensional gel electrophoresis, whereas myosin isozymes were detected by pyrophosphate gel electrophoresis. Myocardial infarction and associated work overload cause a transition in the light chain complements of the myosins. Thus ventricular myosin light chains were found in pressure overloaded atria and atrial light chains have also been identified in the infarct ventricle of the human heart. Two molecular isoenzymes of the human atrial myosin, the relative proportions of which are changed after infarction, were separated under non-dissociating conditions by gel electrophoresis. A decrease in HA-3 and a corresponding increase in HA-1 were observed. Ventricular hypertrophy in patients with coronary insufficiency induces a second ventricle isomyosin, called HV-1, with the same electrophoretic mobility as HA-1. The relative part of this myosin type amounts to 20%. Comparative peptide mapping studies were carried out on myosin subfragment-1 preparations from normal and infarct ventricles. In the primary structures, the chymotrypsic digestions produced slight differences. These data demonstrate the heterogeneity of human atrial and ventricular myosins in patients with coronary heart disease.

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Signal Transduction in Myocardial Hypertrophy and Myosin Expression

Rupp

Jacob

Dhalla

1990

Developments in Cardiovascular Medicine

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Dissociation between factors resulting in hypertrophy and changes in myosin isoenzyme population of the pressure-loaded rat heart

Cited by 6 publications

References 19 publications

Comparison between isomyosin pattern and contractility of right ventricular myocytes isolated from rats with right cardiac hypertrophy

Comparison between isomyosin pattern and contractility of right ventricular myocytes isolated from rats with right cardiac hypertrophy

Atrial and ventricular myosins from human hearts II. Isoenzyme distribution after myocardial infarction

Signal Transduction in Myocardial Hypertrophy and Myosin Expression

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