NADPH-diaphorase histochemistry identifies isolated endothelial cells at sites of traumatic injury in the adult rat brain.
In addition to labelling endothelium, some ependymal cells (including tanycytes), and a subpopulation of neurons, nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry of stab lesion sites in the neocortex revealed a large population of cells concentrated within several hundred micrometers of the lesion site. To determine the identity of these cells, NADPH-diaphorase reactivity was compared to binding with either the I-B4 isolectin from Bandeiraea simplicifolia (which has previously been shown to identify endothelial cells and activated mononuclear phagocytes), or a monoclonal antibody (OX-42) that recognizes activated mononuclear phagocytes. Many I-B4 lectin-labelled cells were also NADPH-diaphorase reactive, and other I-B4 lectin-labelled cells were also OX-42 immunoreactive, but co-existence of OX-42 immunoreactivity and NADPH-diaphorase reactivity was not observed. Only a small minority of NADPH-diaphorase-reactive cells did not exhibit I-B4 lectin binding. In contrast to the simple somatic morphology of the majority of NADPH-diaphorase-reactive cells, the I-B4 lectin-negative cells had a ramified appearance, and while readily observed at two days postlesion, they were only rarely seen at three days postlesion. Primary cultures of bovine aortic endothelial cells also exhibited NADPH-diaphorase reactivity which occupied most of the cytoplasm in a filamentous web pattern. Endothelial cells possess a constitutive form of nitric oxide synthase which, as demonstrated in NADPH-diaphorase-reactive neurons, may be the basis of their NADPH-diaphorase reactivity. These findings indicate that NADPH-diaphorase-reactive cells observed at lesion sites are probably angiogenic endothelial cells not associated with extant blood vessels. Thus, NADPH-diaphorase histochemistry offers an effective method of visualizing neovascularization in the brain and other tissues.
Kitchener
P D
PD
Dept. of Anatomical Sciences, University of Queensland, Brisbane, Australia.
Bourreau
J P
JP
Diamond
J
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology; D004727:Endothelium / Q000166:cytology; D005260:Female; D006651:Histocytochemistry; D037102:Lectins; D008264:Macrophages / Q000648:ultrastructure; D009252:NADPH Dehydrogenase / Q000032:analysis*; D009457:Neuroglia / Q000648:ultrastructure; D037121:Plant Lectins; D051381:Rats; D017208:Rats, Wistar
D000911:Antibodies, Monoclonal; C045475:Griffonia simplicifolia lectins; D037102:Lectins; D037121:Plant Lectins; D009252:NADPH Dehydrogenase