Nitric oxide mediates hypoxia-induced changes in paracellular permeability of cerebral microvasculature.

Cerebral microvascular changes in permeability and tight junctions induced by hypoxia-reoxygenation.

Cerebral microvessel endothelial cells that form the blood-brain barrier (BBB) have tight junctions (TJ) that are critical for maintaining brain homeostasis and low permeability. Both integral (claudin-1 and occludin) and membrane-associated zonula occluden-1 and -2 (ZO-1 and ZO-2) proteins combine to form these TJ complexes that are anchored to the cytoskeletal architecture (actin). Disruption...

Inhibition of nitric oxide synthase activity improves focal cerebral damage induced by cerebral ischemia/reperfusion in normotensive rats

Introduction: Nitric oxide seems to play a dual role in ischemia/reperfusion injury. Few studies have investigated whether it exacerbates or improves brain edema. In the present study, we inhibited the activity of nitric oxide synthase by L-NAME and evaluated the cerebral infarct volume, tissue swelling and brain edema, alongside the measurement of blood flow of the ischemic region. Methods...

Oxide, and Paracellular Permeability Involvement of Afferent Neurons, Nitric Colonic Inflammation in Mice: Possible Proteinase-Activated Receptor-2-Induced

Hypoxia induces permeability in brain microvessel endothelial cells via VEGF and NO.

In this study, an in vitro model of the blood-brain barrier, consisting of porcine brain-derived microvascular endothelial cells (BMEC), was used to evaluate the mechanism of hypoxia-induced hyperpermeability. We show that hypoxia-induced permeability in BMEC was completely abolished by a neutralizing antibody to vascular endothelial growth factor (VEGF). In contrast, under normoxic conditions,...

Nitric oxide mediates hypoxia-induced cerebral vasodilation in humans.

Nitric oxide (NO) plays a pivotal role in the regulation of peripheral vascular tone. Its role in the regulation of cerebral vascular tone in humans remains to be elucidated. This study investigates the role of NO in hypoxia-induced cerebral vasodilatation in young healthy volunteers. The effect of the NO synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on the cerebral blood flow (CBF) wa...