TY - JOUR
T1 - Specialized membrane domains for water transport in glial cells
T2 - High- resolution immunogold cytochemistry of aquaporin-4 in rat brain
AU - Nielsen, So
AU - Nagelhus, Erlend Arnulf
AU - Amiry-Moghaddam, Mahmood
AU - Bourque, Charles
AU - Agre, Peter
AU - Ottersen, Ole Retter
PY - 1997
Y1 - 1997
N2 - Membrane water transport is critically involved in brain volume homeostasis and in the pathogenesis of brain edema. The cDNA encoding aquaporin-4 (AQP4) water channel protein was recently isolated from rat brain. We used immunocytochemistry and high-resolution immunogold electron microscopy to identify the cells and membrane domains that mediate water flux through AQP4. The AQP4 protein is abundant in glial cells bordering the subarachnoidal space, ventricles, and brood vessels. AQP4 is also abundant in osmosensory areas, including the supraoptic nucleus and subfornical organ. Immunogold analysis demonstrated that AQP4 is restricted to glial membranes and to subpopulations of ependymal cells. AQP4 is particularly strongly expressed in glial membranes that are in direct contact with capillaries and pia. The highly polarized AQP4 expression indicates that these cells are equipped with specific membrane domains that are specialized for water transport, thereby mediating the flow of water between glial cells and the cavities filled with CSF and the intravascular space.
AB - Membrane water transport is critically involved in brain volume homeostasis and in the pathogenesis of brain edema. The cDNA encoding aquaporin-4 (AQP4) water channel protein was recently isolated from rat brain. We used immunocytochemistry and high-resolution immunogold electron microscopy to identify the cells and membrane domains that mediate water flux through AQP4. The AQP4 protein is abundant in glial cells bordering the subarachnoidal space, ventricles, and brood vessels. AQP4 is also abundant in osmosensory areas, including the supraoptic nucleus and subfornical organ. Immunogold analysis demonstrated that AQP4 is restricted to glial membranes and to subpopulations of ependymal cells. AQP4 is particularly strongly expressed in glial membranes that are in direct contact with capillaries and pia. The highly polarized AQP4 expression indicates that these cells are equipped with specific membrane domains that are specialized for water transport, thereby mediating the flow of water between glial cells and the cavities filled with CSF and the intravascular space.
KW - CSF
KW - aquaporin-4 water channel
KW - brain water permeability
KW - ependymal cells
KW - glial cells
KW - immunogold electron microscopy
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U2 - 10.1523/jneurosci.17-01-00171.1997
DO - 10.1523/jneurosci.17-01-00171.1997
M3 - Article
C2 - 8987746
AN - SCOPUS:0031022918
SN - 0270-6474
VL - 17
SP - 171
EP - 180
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 1
ER -