Biomaterial Database

Hypoxia modulates free radical formation in brain microvascular endothelium. 1997

A Strasser, and D Stanimirovic, and N Kawai, and R M McCarron, and M Spatz

Stroke Banch NINDS, National Institutes of Health, Bethesda, MD, USA.

Although free radical species (ROS; i.e., .O2-. .OH.H2O2) among other mediators, may be involved in altering the blood-brain barrier (BBB), little is known about the endogenous ability of cerebromicrovascular endothelium to generate ROS. This study examines the capacity of rat endothelial cells (RBEC) to produce ROS in normoxia and hypoxia/reoxygenation. Cultured RBEC were exposed to an oxygen-depleted atmosphere (containing 95% N2 and 5% CO2) for 4 hr at 37 degrees C and air (10 min) at room temperature to simulate "ischemia/reperfusion". Nitroblue tetrazolium (NBT) reduction [formation of nitroblue formazan (NBF)] served as a marker for the production of ROS. The release of lactate dehydrogenase (LDH) and [3H]arachidonic acid (AA) was used to assess cellular integrity. RBEC exposed to hypoxia/reoxygenation produced up to 59% greater NBF formation than controls without affecting the LDH or AA release. The production of ROS was calcium-dependent and not affected by AA or its metabolites. The findings indicate that the RBEC can produce superoxide dismutase (SOD)-inhibitable ROS which are augmented by hypoxia/reoxygenation. It is suggested that in vivo cerebromicrovascular endothelium may contribute to the formation of ROS and play a role in ischemic brain edema.

UI	MeSH Term	Description	Entries
D001812	Blood-Brain Barrier	Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.	Brain-Blood Barrier,Hemato-Encephalic Barrier,Barrier, Blood-Brain,Barrier, Brain-Blood,Barrier, Hemato-Encephalic,Barriers, Blood-Brain,Barriers, Brain-Blood,Barriers, Hemato-Encephalic,Blood Brain Barrier,Blood-Brain Barriers,Brain Blood Barrier,Brain-Blood Barriers,Hemato Encephalic Barrier,Hemato-Encephalic Barriers
D002534	Hypoxia, Brain	A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.	Anoxia, Brain,Anoxic Encephalopathy,Brain Hypoxia,Cerebral Anoxia,Encephalopathy, Hypoxic,Hypoxic Encephalopathy,Anoxia, Cerebral,Anoxic Brain Damage,Brain Anoxia,Cerebral Hypoxia,Hypoxia, Cerebral,Hypoxic Brain Damage,Anoxic Encephalopathies,Brain Damage, Anoxic,Brain Damage, Hypoxic,Damage, Anoxic Brain,Damage, Hypoxic Brain,Encephalopathies, Anoxic,Encephalopathies, Hypoxic,Encephalopathy, Anoxic,Hypoxic Encephalopathies
D004730	Endothelium, Vascular	Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.	Capillary Endothelium,Vascular Endothelium,Capillary Endotheliums,Endothelium, Capillary,Endotheliums, Capillary,Endotheliums, Vascular,Vascular Endotheliums
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D017382	Reactive Oxygen Species	Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of SIGNAL TRANSDUCTION and GENE EXPRESSION, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.	Active Oxygen Species,Oxygen Radical,Oxygen Radicals,Pro-Oxidant,Reactive Oxygen Intermediates,Active Oxygen,Oxygen Species, Reactive,Pro-Oxidants,Oxygen, Active,Pro Oxidant,Pro Oxidants,Radical, Oxygen
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus