Show simple item record

dc.contributor.authorNielsen, S
dc.contributor.authorAgre, P
dc.contributor.authorHudson, C S
dc.contributor.authorYasumura, T
dc.contributor.authorRash, J E
dc.date.accessioned2010-03-10T21:58:49Z
dc.date.available2010-03-10T21:58:49Z
dc.date.issued1998-09-29
dc.identifier.citationProc Natl Acad Sci U S A. 1998 Sep 29;95(20):11981-6. http://www.pnas.org/content/95/20/11981.fullen
dc.identifier.urihttp://jhir.library.jhu.edu/handle/1774.2/33958
dc.description.abstractAquaporin (AQP) water channels are abundant in the brain and spinal cord, where AQP1 and AQP4 are believed to play major roles in water metabolism and osmoregulation. Immunocytochemical analysis of the brain recently revealed that AQP4 has a highly polarized distribution, with marked expression in astrocyte end-feet that surround capillaries and form the glia limitans; however, the structural organization of AQP4 has remained unknown. In freeze-fracture replicas, astrocyte end-feet contain abundant square arrays of intramembrane particles that parallel the distribution of AQP4. To determine whether astrocyte and ependymocyte square arrays contain AQP4, we employed immunogold labeling of SDS-washed freeze-fracture replicas and stereoscopic confirmation of tissue binding. Antibodies to AQP4 directly labeled approximately 33% of square arrays in astrocyte and ependymocyte plasma membranes in rat brain and spinal cord. Overall, 84% of labels were present beneath square arrays; 11% were beneath particle clusters that resembled square arrays that had been altered during fixation or cleaving; and 5% were beneath the much larger areas of glial plasma membrane that were devoid of square arrays. Based on this evidence that AQP4 is concentrated in glial square arrays, freeze-fracture methods may now provide biophysical insights regarding neuropathological states in which abnormal fluid shifts are accompanied by alterations in the aggregation state or the molecular architecture of square arrays.en
dc.language.isoen_USen
dc.publisherNational Academy of Sciencesen
dc.subjectSpinal Cord/metabolismen
dc.subjectIon Channels/metabolismen
dc.subjectBrain/metabolismen
dc.subjectAstrocytes/metabolismen
dc.subjectAquaporinsen
dc.titleDirect immunogold labeling of aquaporin-4 in square arrays of astrocyte and ependymocyte plasma membranes in rat brain and spinal corden
dc.typeArticleen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record