RT Journal Article
SR Electronic
T1 Water transport becomes uncoupled from K<sup>+</sup> siphoning in brain contusion, bacterial meningitis, and brain tumours: immunohistochemical case review
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 972
OP 975
DO 10.1136/jcp.56.12.972
VO 56
IS 12
A1 Saadoun, S
A1 Papadopoulos, M C
A1 Krishna, S
YR 2003
UL http://jcp.bmj.com/content/56/12/972.abstract
AB Specimens of normal human brain, contused brain, brain with bacterial meningitis, and brain tumours were immunolabelled for aquaporin 4 (AQP4) and Kir4.1. In normal brain tissue, AQP4 and Kir4.1 were detected around the microvessels. In pathological brain tissue, AQP4 was upregulated in astrocytes in oedematous regions and Kir4.1 was upregulated in astrocytes in damaged brain. Changes in α syntrophin expression paralleled those of AQP4 and Kir4.1. The following hypothesis is proposed: in astrocytes, under normal conditions, AQP4 couples water transport with Kir4.1 mediated K+ siphoning, but in pathological states, AQP4 facilitates the flow of brain oedema fluid, and Kir4.1 buffers increased extracellular K+.