Review: Isolated cardiac myocytes: I Preparation of adult myocytes and their homology with the intact tissue

Dow, Jocelyn W.; Harding, Nigel G. L.; Powell, T.

doi:10.1093/cvr/15.9.483

Cited by 145 publications

(54 citation statements)

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“…or bistable foci observed were 1-2 microns in size-a dimension comparable to that of an individual cardiac mitochondrion (19,20).…”

Section: Resultsmentioning

confidence: 87%

“…The resulting correlation map displays a large and narrow central peak with a maximum at 0.75 (1 being a perfect correlation), indicating coincidence of both images. A number of peripheral peaks are also evident, arising from the periodic structure conferred by the packing of mitochondria along myofibrillar bundles (periodicities in the Y-dimension) and between sarcomeric z-lines (periodicities in the X-dimension) (19).…”

Section: Resultsmentioning

confidence: 99%

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Subcellular metabolic transients and mitochondrial redox waves in heart cells

Romashko

Marbán

O’Rourke

1998

Proc. Natl. Acad. Sci. U.S.A.

190

158

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Precise matching of energy supply with demand requires delicately balanced control of the enzymes involved in substrate metabolism. In response to a change in substrate supply, the nonlinear properties of metabolic control may induce complex dynamic behavior. Using confocal imaging of f lavoprotein redox potential and mitochondrial membrane potential, we show that substrate deprivation leads to subcellular heterogeneity of mitochondrial energization in intact cells. The complex spatiotemporal patterns of redox and matrix potential included local metabolic transients, cell-wide coordinated redox transitions, and propagated metabolic waves both within and between coupled cells. Loss of metabolic synchrony during mild metabolic stress reveals that intra-and intercellular control of mitochondrial function involves diffusible cytoplasmic messengers.Nonlinear dynamic control in metabolic pathways plays a crucial role in conferring sensitivity and rapid responses to changes in cellular workload or environmental conditions. Through a combination of allosteric and stoichiometric effects on multiple control points, the enzymatic pathways involved in energy metabolism can undergo large changes in activity in response to small perturbations of key effector molecules (1). Experimental and theoretical studies have demonstrated that, under some conditions, such finely tuned systems may become unstable and display self-organizing oscillations, bistability, or chaotic behavior (reviewed in ref.2). Early observations of metabolic oscillations in yeast (3-5) and our own investigation of oscillations of NADH and sarcolemmal K,ATP current in substrate-deprived heart cells (6) provide evidence that such phenomena can be observed in intact cells. In our previous work, modulation of the amplitude and͞or frequency of the oscillations by external glucose led to the hypothesis that they were driven by a glycolytic oscillator, but the predominantly mitochondrial origin of the NADH f luorescence in cardiomyocytes (7) suggested that metabolic transients in oxidative phosphorylation were also present.To investigate the mitochondrial component of the oscillations, the present study uses the endogenous fluorescence of flavoproteins to image redox oscillations in the mitochondrial matrix. Subcellular imaging reveals a remarkable degree of spatial and temporal heterogeneity in mitochondrial redox and electrical potential, including local transients and propagated metabolic waves. The last observation suggests that communication between mitochondria in the same or neighboring cells is likely to involve diffusible cytosolic messengers acting to synchronize the energy state of the entire population of mitochondria.

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“…or bistable foci observed were 1-2 microns in size-a dimension comparable to that of an individual cardiac mitochondrion (19,20).…”

Section: Resultsmentioning

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Subcellular metabolic transients and mitochondrial redox waves in heart cells

Romashko

Marbán

O’Rourke

1998

Proc. Natl. Acad. Sci. U.S.A.

190

158

View full text Add to dashboard Cite

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“…The value of the isolated heart muscle cell for structural and functional studies has widely been recognized for more than ten years (Dow et al, 1981). Advantages of single cell preparations are the homogeneity of the cell population which makes it possible to evaluate the characteristics of individual cells in the absence of external influences, i.e.…”

Section: Discussionmentioning

confidence: 99%

“…Advantages of single cell preparations are the homogeneity of the cell population which makes it possible to evaluate the characteristics of individual cells in the absence of external influences, i.e. interactions between myocytes and microvasculature, regional differences in blood flow, influences of neighbouring tissues, neuronal, mechanical, and hormonal modulation (Dow et al, 1981;Piper et al, 1982;Borgers et al, 1988). In addition, since a large number of cells are obtained from one organ, a multitude of experiments can be carried out, 6.7pgml-l to 670pgml-), in addition to rose bengal, in relation to incubation with rose bengal alone (= 100%).…”

Section: Discussionmentioning

confidence: 99%

Protective action of hydroxyethyl rutosides on singlet oxygen-challenged cardiomyocytes

Olbrich¹,

Grabisch²,

Matheis³

et al. 1995

Cardiovascular Surgery

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“…On the other hand these workers and Fox et al (1987) found that the dihydropyridine agonist Bay K 8644 gives rise to a negative shift of the activation curve. We may rule out the possibility that inhibition of nearonal catecholamine release is involved since isolated myocytes are effectively denervated (Dow et al, 1981) and the effects of the drug on the activation variable are not those which would be expected from reversal of /-adrenoceptor stimulation (Cohen & Lederer, 1987). Angiotensin II increases the calcium current in neonatal rat ventricular myocytes (Allen et al, 1987).…”

Section: Discussionmentioning

confidence: 99%

Effects of captopril on membrane current and contraction in single ventricular myocytes from guinea‐pig

Bryant

Ryder

Hart

1991

British J Pharmacology

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1Single guinea-pig ventricular myocytes were voltage-clamped and cell length was measured with a photodiode array. 2 Captopril (1 x 10-5M) reduced both peak early current and active shortening in response to a depolarizing clamp pulse along a similar time course. 3 From a holding potential of around -45 mV peak early inward current was reduced by 37 + 9% (P < 0.001) on exposure to captopril. The early current-voltage relationship was shifted outwards by captopril indicating a reduction in membrane conductance through the L-type calcium channel (ICa). 4 The amplitude of cell shortening in response to depolarizing voltage steps was reduced but the voltage-dependence of contraction after captopril was unchanged.5 A small negative shift of the potential at which Ica was half-activated was observed after captopril.There was no change in the voltage-dependence of the inactivation variable or in the time-dependence of repriming for ICa 6 The actions of captopril on ICa and developed shortening were dose-dependent and took place in the same proportion when ICa was increased by isoprenaline. 7 These results are discussed in relation to the effects of captopril on ICa and contraction and to its clinical usage.

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Review: Isolated cardiac myocytes: I Preparation of adult myocytes and their homology with the intact tissue

Cited by 145 publications

References 0 publications

Subcellular metabolic transients and mitochondrial redox waves in heart cells

Subcellular metabolic transients and mitochondrial redox waves in heart cells

Protective action of hydroxyethyl rutosides on singlet oxygen-challenged cardiomyocytes

Effects of captopril on membrane current and contraction in single ventricular myocytes from guinea‐pig

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