PHTHALOCYANINE PHOTOSENSITIZATION OF MAMMALIAN CELLS: BIOCHEMICAL and ULTRASTRUCTURAL EFFECTS |
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Authors: | E. Ben-Hur M. Green A. Prager R. Kol I. Rosenthal |
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Affiliation: | Department of Biology, College of General Education, Osaka University, Toyonaka, Osaka 560, Japan;Department of Molecular Biology, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560, Japan;Departments of Physiology, Osaka Medical College, Takatsuki, Osaka 569, Japan |
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Abstract: | Abstract— The concentrations of Na+, K+, Ca2+, Mg2+ and CI− ions in the cytoplasm of octopus photoreceptor cells were determined before and after illumination by electron probe X-ray microanalysis. The concentrations of these elements in the dark-adapted photoreceptor cells were: Na+, 68.4; K+, 111.4; Ca2+, 4.0; Mg2+, 16.4; and CI−, 102.9 m M /kg of cytoplasm. Illumination raised the concentration of Na+ by 58 m M and that of Cl− by 23 m M and reduced the K+ concentration by 47 m M /kg of cytoplasm. A trace increase of intracellular Ca2+ and a trace decrease of Mg2+ were observed. These results confirm the hypothesis that sodium ions flow in on illumination, and suggest the influx of chloride ions and the outflux of potassium ions during illumination. The intracellular concentrations of Na+, K+ and Cl+ can give the basis for calculating the ion permeability of ion channels in octopus photoreceptor cell membranes, using values of the membrane potentials obtained by electrophysiological studies |
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