Fluorescent styryl dyes applied as fast optical probes of cardiac action potential

Müller, Wolfram; Windisch, H.; Tritthart, H. A.

doi:10.1007/bf00263067

Cited by 29 publications

(13 citation statements)

References 34 publications

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“…The proposed mechanism of the styryl dyes is based mainly on the e ect of electrochromy, by which changes of the (local) electric ®eld inside the membrane dielectric shift the absorption spectra and thus a ect the¯uorescence yield when the chromophore is excited at a wavelength preferentially at the red edge of its absorption spectrum (Loew et al, 1979;Fluhler et al, 1985;BuÈ hler et al, 1991). Besides the electrochromic shift of the absorption spectrum of styryl dyes, their voltage response may depend on additional components, which also a ect the excitation process of the dye molecules, as was discussed by several authors (Fluhler et al, 1985;MuÈ ller, Windisch & Tritthart, 1986;Ephardt & Fromherz, 1989;Fedosova et al, 1995).…”

Section: Introductionmentioning

confidence: 96%

Detection of Charge Movements in Ion Pumps by a Family of Styryl Dyes

Pedersen

Roudná

Beutner

et al. 2002

Journal of Membrane Biology

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Abstract. A family of¯uorescent styryl dyes was synthesized to apply them as probes that monitor the ion-translocating activity of the Na,K-ATPase and the SR Ca-ATPase, similar to the widely used dye RH421. All dyes had the same chromophore but they di ered in the length of the spacer between chromophore and polar head, an isothiocyanate group, and in the lengths of the two identical acyl chains, which form the tail of the dye molecules. A number of substrate-dependent partial reactions of both P-type ATPases a ected the¯uorescence intensity, and the magnitude of the¯uorescence changes was used to characterize the usefulness of the dyes for further application. The experimental results indicate that electrochromy is the major mechanism of these dyes. While in the case of the Na,K-ATPase a single dye, 5QITC, showed larger¯uorescence changes than all others, in the case of the SR Ca-ATPase all dyes tested were almost equal in their¯uorescence responses. This prominent di erence is interpreted as a hint that the position of the ion binding sites in both ion pumps may di er signi®cantly despite their otherwise closely related structural features. Quench experiments with spin-labeled lipids in various positions of their fatty acids were used to gain information on the depth of the chromophore of the di erent dyes within the membrane dielectric, however, the spatial resolution was so poor that only qualitative information on the position of the chromophore in the lipid phase could be obtained.

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Section: Introductionmentioning

confidence: 96%

Detection of Charge Movements in Ion Pumps by a Family of Styryl Dyes

Pedersen

Roudná

Beutner

et al. 2002

Journal of Membrane Biology

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“…In most cases, a few milliseconds before and after a measurement, the specimen was excited for 2 ms with the violet light of an Argon-Ion laser (457 nm). At this wavelength the voltage sensitivity of the dye is small compared to that of a greenlight excitation [3]. An evaluation of the intensity of the fluorescence light before, during and after a measurement allowed us to compensate for baseline drifts of the optical signal caused by dye bleaching.…”

Section: Methodsmentioning

confidence: 99%

Structure related membrane polarizations in field stimulated guinea pig papillary muscle

Windisch

Daprà

Köhler

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Abstract-We have performed optical potential mapping with very high temporal and spatial resolution in guinea pig papillary muscles during the application of electrical pulses. We used a surface staining procedure, with the potential sensitive dye di-4-ANEPPS, throughout our experiments which limited the depth of contribution to the optical signal to less than 40 µm [1]. Our results gave clear evidence, that the structural inhomogeneities themselves, in regions within about a space constant (< 1 mm), were able, during the application of an electrical pulse, to cause strong membrane polarizations. These polarizations, occurring far from electrodes, were sufficient to trigger local electrical activities. Our findings strongly support hypotheses, which assume, that the tissue structure -especially in regions far from electrodes or from the surface of the heart -play an important role in the defibrillation process. Keywords -optical potential mapping, field stimulationField induced transmembrane potential changes are the necessary link to the resulting electrical interferences such as e.g. cardiac stimulation or defibrillation work in cardiac tissue. As predicted in several mathematical models, and measured in biological preparations, the tissue structure with its specific shape, dimension and inhomogeneities play a major role in the generation of these pulse induced membrane voltages. It is still an open question, to which extent inhomogeneities of various size scales can contribute to these polarization induced membrane voltages, which in turn may elicit an action potential, or even stop fibrillation. As was shown in an earlier study by Müller et al. [2] small inhomogeneities in guinea pig papillary muscles caused severe distortions in the spread of excitation. In the present paper we used the same type of preparation to study field induced membrane voltages, appearing within the range of 1 mm ( i.e. within about a space constant). II. METHODOLOGYGuinea pig papillary muscles were stained with the voltage sensitive dye di-4-ANEPPS and mounted in a tissue bath. During the whole experiment the preparation was kept under near physiological conditions (Tyrode's solution at 36 o C, Oxygen saturated). A pair of current driven platinum electrodes was used to deliver electrical pulses with the electrical field strength oriented parallel to the main axis of the muscle. During a measurement, the green light of a frequency doubled Neodymium-Yag laser (100 mW, 532 nm) = This investigation was supported by the Austrian Science Fund, Grand No. P 12294-Med was used to excite the fluorescence of the stained specimen, which showed a voltage sensitivity of up to 10 % intensity change per 100 mV membrane potential change. In most cases, a few milliseconds before and after a measurement, the specimen was excited for 2 ms with the violet light of an Argon-Ion laser (457 nm). At this wavelength the voltage sensitivity of the dye is small compared to that of a greenlight excitation [3]. An evaluation of the intensity of the fluorescence ...

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“…Before introducing the synthesis filters we use up-sampling. References [6][7][8][9][10][11] cover how to apply filter banks to increase signal to noise ratio.…”

Section: International Journal Of Computer Applications (0975 -8887) mentioning

confidence: 99%

Pseudo Body Surface Potential Mapping on Heart using 3D Wavelet Transform

Sharawy¹,

Samy²,

Aouf³

2013

IJCA

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Body surface potential mapping (BSPM) is used to detect real diagnostic information about the myocardium state more than the standard 12-lead electrocardiogram (ECG). The present research introduces a practical solution for recording body surface potential maps using the standard 12-lead ECG with different positions. It is called pseudo BSPM where all channels were not read out simultaneously. It is based on the assumption that heart beat body surface potential mapping (BSPM) is used to detect real diagnostic information about the myocardium state more than standard 12-lead electrocardiography (ECG). Pseudo BSPM pattern is not changed considerably during the whole measurement session. Body surface potential mapping was applied to normal and abnormal persons suffering from coronary heart diseases (CHD). We detect QRS complexes using filter banks and consequently build up a cardiac map using 3D wavelet transform. Our results for the cardiac map demonstrate the changes that occur for the cardiac electrical activity which represents the patient case in color degradation patterns.

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Fluorescent styryl dyes applied as fast optical probes of cardiac action potential

Cited by 29 publications

References 34 publications

Detection of Charge Movements in Ion Pumps by a Family of Styryl Dyes

Detection of Charge Movements in Ion Pumps by a Family of Styryl Dyes

Structure related membrane polarizations in field stimulated guinea pig papillary muscle

Pseudo Body Surface Potential Mapping on Heart using 3D Wavelet Transform

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