Reactive astrocytes express NADPH diaphorase in vivo after transient ischemia.
In the hippocampus, ten minutes of transient global ischemia results in the death of CA1 pyramidal cells after a period of one to three days. The neurons in the CA1 region constitutively express NADPH-D (NADPH diaphorase activity). In contrast, astrocytes in the hippocampus do not normally express NADPH-D; but a population of reactive astrocytes (GFAP+ cells) begin to express of NADPH-D one day after transient global ischemia. NADPH-D is thought to be a histological marker for Nitric Oxide Synthase (NOS), the enzyme that is responsible for the synthesis of NO, a potent neurotoxin. We suggest that this increase in NADPH-D/NOS expression is an important element in the sequence of changes that occurs after ischemia, and that NO derived from reactive astrocytes or from neurons may play a causal role in neural cell death after ischemia in the hippocampus.
Endoh
M
M
Department of Neurology and Neuroscience, Cornell University Medical College, New York, NY 10021.
Maiese
K
K
Pulsinelli
W A
WA
Wagner
J A
JA
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000818:Animals; D001253:Astrocytes / Q000201:enzymology*; D004790:Enzyme Induction; D005904:Glial Fibrillary Acidic Protein / Q000276:immunology / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000201:enzymology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D002546:Ischemic Attack, Transient / Q000201:enzymology*; D009252:NADPH Dehydrogenase / Q000096:biosynthesis*; D009457:Neuroglia / Q000201:enzymology; D019001:Nitric Oxide Synthase; D051381:Rats
D005904:Glial Fibrillary Acidic Protein; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009252:NADPH Dehydrogenase