3-D measurement of osmotic dehydration of isolated and adhered PC-3 cells.
Cell dehydration during freezing results from an elevated concentration of electrolytes in the extracellular medium that is deeply involved in cellular injury. We undertook real-time threedimensional (3-D) observation of osmotic dehydration of cells, motivated by a comparison of cellular responses between isolated cells in suspension and cultured cells adhering to a surface since several studies have suggested a difference in freeze tolerance between cell suspensions and monolayers. A laser confocal scanner was used with a perfusion microscope to capture sectional images of chloromethylbenzamido (DiI)-stained PC-3 cells that were exposed to an increase in NaCl concentration from 0.15 to 0.5M at 23 degrees C. Change in cell volume was determined from reconstructed 3-D images taken every 2.5s. When cells were exposed to an elevated NaCl concentration, isolated cells contracted and markedly distorted from their original spherical shape. In contrast, adhered cells showed only a reduction in height and kept their basal area constant. Apparent membrane hydraulic conductivity did not vary considerably between isolated and adhered cells, suggesting a negligible effect of the cytoskeletal structure on the rate of water transport. The surface area that contributed to water transport in adhered PC-3 cells was nearly equal to or slightly smaller than that present in isolated cells. Therefore, the similarity in properties and dimensions between isolated and adhered cells indicate that there will be similar extents of dehydration, resulting in a similar degree of supercooling during freezing.
Yoshimori
Takashi
T
Department of Mechanical Engineering Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Takamatsu
Hiroshi
H
Department of Mechanical Engineering Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. Electronic address: takamatsu@mech.kyushu-u.ac.jp.
D002448:Cell Adhesion; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002463:Cell Membrane Permeability; D002469:Cell Separation; D048430:Cell Shape; D003681:Dehydration / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D018613:Microscopy, Confocal; D009995:Osmosis; D012965:Sodium Chloride / Q000737:chemistry; D014867:Water / Q000378:metabolism
D014867:Water; D012965:Sodium Chloride