The mechanism of PDT-induced electrical blockade: The dependence of time-lapse localization of talaporfin sodium on the cell death phenotypes in rat cardiac myocytes

A. Ito, H. Matsuo, T. Suenari, S. Miyoshi, Seiji Takatsuki, S. Ogawa, Tsunenori Arai

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

We have proposed a new type of atrial fibrillation treatment with the early state photodynamic therapy (PDT), in which the interval time between the photosensitizer injection and irradiation is shorter than that in conventional way. We had demonstrated the acute electrical blockade by the PDT with talaporfin sodium and a red (670 nm) diodelaser in ex vivo and in vivo experiment using rat normal myocardial tissue. The previous study of intracellular Ca2+ concentration measurement in rat cardiac myocytes during the PDT indicated that Ca2+ influx induced by the plasma membrane damage might be the main cause of the acute reaction of myocardial tissue. We found that the cell damage of cardiac myocytes triggered by the PDT was mainly influenced by the site where the photosensitizer exists. In this study, we examined the relationship between the sites of talaporfin sodium existing and cell death phenotypes in response to the PDT, in order to clarify the mechanism of the acute electrical blockade induced by the PDT in myocardial tissue. The talaporfin sodium fluorescence was observed after the various incubation times to visualize the time-lapse intracellular photosensitizer localization. The distribution of the photosensitizer was dependent on the incubation time. The change in intracellular Ca2+ concentration during the PDT was examined with a fluorescent Ca2+ indicator by a high-speed Nipkow confocal laser microscope (CSU-X1, Yokogawa Electric Company). We obtained the Ca2+ dynamics during the PDT which can explain the PDT-induced cell death pathways. We concluded that the Ca2+ influx induced by plasma membrane damage is the possible mechanism of the electrical blockade by the early state PDT.

Original languageEnglish
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume7164
DOIs
Publication statusPublished - 2009
EventOptical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XVIII - San Jose, CA, United States
Duration: 2009 Jan 242009 Jan 25

Other

OtherOptical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XVIII
CountryUnited States
CitySan Jose, CA
Period09/1/2409/1/25

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Keywords

  • Atrial fibrillation
  • Electrical blockade
  • Intracellular Ca concentration
  • Photodynamic therapy
  • Subcellular localization
  • Talaporfin sodium

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

Cite this

Ito, A., Matsuo, H., Suenari, T., Miyoshi, S., Takatsuki, S., Ogawa, S., & Arai, T. (2009). The mechanism of PDT-induced electrical blockade: The dependence of time-lapse localization of talaporfin sodium on the cell death phenotypes in rat cardiac myocytes. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 7164). [716412] https://doi.org/10.1117/12.807810