The possible influence of osmotic poration on cell membrane water permeability.
It has been hypothesized that pores in the plasma membrane form under conditions of rapid water efflux, allowing extracellular ice to grow into the cytoplasm under conditions of rapid freezing. When cells with intracellular ice are thawed slowly, the transmembrane ice crystal expands through recrystallization causing the cell to lyse. One of the implications of this hypothesis is that osmotic pores will provide an alternative route for water movement under conditions of osmotically induced flow. We show that the plasma membrane water permeability of a fibroblast cell changes as a function of the osmotic pressure gradient that is used to drive water movement. It is further shown that cell volume is more important than the magnitude of water flux in causing this departure from a uniform water permeability. We suggest that these data provide evidence of a transient route for water movement across cell membranes.
Muldrew
Ken
K
Dept. of Cell Biology and Anatomy, University of Calgary, 3330 Hospital Drive NW, Calgary, Alta., Canada T2N 4N1. Electronic address: kmuldrew@ucalgary.ca.
Schachar
Jaime
J
Dept. of Cell Biology and Anatomy, University of Calgary, 3330 Hospital Drive NW, Calgary, Alta., Canada T2N 4N1.
Cheng
Phil
P
Dept. of Cell Biology and Anatomy, University of Calgary, 3330 Hospital Drive NW, Calgary, Alta., Canada T2N 4N1.
Rempel
Corbin
C
Dept. of Cell Biology and Anatomy, University of Calgary, 3330 Hospital Drive NW, Calgary, Alta., Canada T2N 4N1.
Liang
Sherri
S
Dept. of Cell Biology and Anatomy, University of Calgary, 3330 Hospital Drive NW, Calgary, Alta., Canada T2N 4N1.
Wan
Richard
R
Dept. of Civil Engineering, University of Calgary, Canada.
D000818:Animals; D002460:Cell Line; D002463:Cell Membrane Permeability; D048429:Cell Size; D002470:Cell Survival; D006224:Cricetinae; D015638:Cytochalasin D / Q000737:chemistry; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D009997:Osmotic Pressure; D012996:Solutions / Q000737:chemistry; D013395:Sucrose / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000378:metabolism*
D012996:Solutions; D014867:Water; D015638:Cytochalasin D; D013395:Sucrose