Upregulation of proinflammatory proteins through NF-kappaB pathway by shed membrane microparticles results in vascular hyporeactivity.

Objective: Microparticles are membrane vesicles with procoagulant and proinflammatory properties released during cell activation, including apoptosis. The present study was designed in dissecting the effects evoked by microparticles on vascular reactivity.

Methods And Results: Microparticles from either apoptotic T lymphocytic cells or from plasma of diabetic patients with vascular complications induced vascular hyporeactivity in response to vasoconstrictor agents in mouse aorta.

Insulin resistance in spontaneously hypertensive rats is associated with endothelial dysfunction characterized by imbalance between NO and ET-1 production.

Insulin stimulates production of NO in vascular endothelium via activation of phosphatidylinositol (PI) 3-kinase, Akt, and endothelial NO synthase. We hypothesized that insulin resistance may cause imbalance between endothelial vasodilators and vasoconstrictors (e.g.

Cyclooxygenase-2 and inducible nitric oxide synthase in omental arteries harvested from patients with severe liver diseases: immuno-localization and influence on vascular tone.

Objective: To investigate the expression of inducible cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS) and the role of vasodilatory prostanoids and endogenous nitric oxide (NO) in small omental arteries harvested from patients with severe liver diseases.

Design: Ex vivo study of resistance arteries. SETTING.