Distribution of Aquaporin 9 in the adult rat brain: Preferential expression in catecholaminergic neurons and in glial cells

Protective Role of Early Aquaporin 4 Induction against Postischemic Edema Formation

“…Chemicon International) was also performed and gave negative results as previously observed (Badaut et al, 2004;de Castro Ribeiro et al, 2006b). …”

Cytoprotective effects of growth factors: BDNF more potent than GDNF in an organotypic culture model of Parkinson's disease

“…In the brain, Aqp9 mRNA was first found in rat astrocytes (11) and confirmed by immunohistochemical studies in the rodent brain (17,264,269,270). In these initial studies, Elkjaer and colleagues (264) reported expression of AQP9 in certain glial cells, including ependymal cells lining the ventricles and tanycytes of the mediobasal hypothalamus, but not in astrocytes or neurons, which was reproduced by others (270).…”

“…In these initial studies, Elkjaer and colleagues (264) reported expression of AQP9 in certain glial cells, including ependymal cells lining the ventricles and tanycytes of the mediobasal hypothalamus, but not in astrocytes or neurons, which was reproduced by others (270). Using PCR, immunocytochemistry and Western blotting, Badaut and colleagues (269) reported the presence of AQP9 in endothelial cells of pial vessels and in astrocyte cell bodies and processes in mice, with high intensity in glia limitans and white matter, as well as in the subfornical organ and cerebellar Bergmann glia (17). In rats, they further reported a prominent expression of AQP9 in catecholaminergic cell bodies and proximal fibers in the brain stem and hypothalamus but not the habenula or in other monoaminergic cell groups (17).…”

“…Subsequent protein studies confirmed abundant expression in liver, where it was shown to be localized in hepatocytic plasma membranes facing the sinusoids (264,(269)(270)(271). AQP9 protein and mRNA has also been demonstrated in several other organs and cells, including testis (264,271) spleen (264), leukocytes (12,272), lung (12), bone marrow (12), retina (273), adipose tissue (274,275), small intestine and brain (17,264,269).…”

“…AQP9 is an aquaglyceroporin with particularly broad substance permeability, transporting water, glycerol, monocarboxylates and arsenite, among others (10)(11)(12)(13)(14). This water channel has recently been found to be selectively expressed in dopaminergic plasma membranes as well as mitochondrial inner membranes in the SN (15)(16)(17), indicating that it may serve as a toxin influx route into these cells, thereby accounting for an increased susceptibility to cell death. AQP4, on the other hand, is an orthodox aquaporin exclusively permeable to water.…”