Figure 11. Analysis of stretch induced changes in the total concentration (σ) of sodium (σNa) and calcium (σCa) with electronprobe microanalysis (EPMA).

Figure 11

Analysis of stretch induced changes in the total concentration (σ) of sodium (σNa) and calcium (σCa) with electronprobe microanalysis (EPMA). A: longitudinal cryosection of murine ventricular myocytes frozen after stimulation without stretch (left panel) and after stimulation and 2 min stretch (right panel). Nucleus (n), nuclear envelope (nu), mitochondria (m), z-lines (z) are well recognizable. B: σ[Na]-map. The elemental spectra were collected pixel by pixel (pixel size 16 nm, 40 s dwell time) in the region included in the orange frame of the cyrosection from the control myocytes (left panel) and form the stretched myocytes (right panel). σ[Na] are given in full false colors. N: nucleus, cy: cytosol. C: Upper maps. σ[Ca] in full false color scale in the mapped regions of the two cells. Left panel = control cell, right panel =stretched cell. Lower maps: red pixel with σ[Ca] higher than 8 mmol (kg dw)-1 were superimposed to the simultaneously collected phosphor map (grey image) in order to better attribute the concentrations of the "hot spots" if σ[Ca] to membrane structures. Whereas in the control cell only few pixel with high σ[Ca] are detectable in the nuclear envelope and in the nucleus (most "hot spots" are on perinuclear organelles), in the stretched cell a large number of pixel with high σ[Ca] are shown in nuclear envelope as well as just internal (nucleus) and external (cytosol) to it. The maps or the two experiments were collected under identical analysis conditions. Elemental digital maps confirm the data of static analysis. (From Kondratev and Gallitelli [44], with permission). (See color insert # 13).

From: Isolated Cardiomyocytes: Mechanosensitivity of Action Potential, Membrane Current and Ion Concentration

Cover of Mechanosensitivity in Cells and Tissues
Mechanosensitivity in Cells and Tissues.
Kamkin A, Kiseleva I, editors.
Moscow: Academia; 2005.
Copyright © 2005, Academia Publishing House Ltd.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.