leukotriene-c4 and Hypercholesterolemia

The aim of this study was to investigate the effect of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor fluvastatin (Flu) on angiotensin II (AII)-stimulated neutrophils of patients with hypercholesterolemia. Results suggest that a 6-week-long Flu administration completely counteracted the AII-induced increase in superoxide anion and leukotriene C4 production of the neutrophils of patients with hypercholesterolemia. However, the failure of signal processing through pertussis toxin-sensitive G protein, the increase in [Ca2+]i in membrane-bound protein kinase C activity, and the increase in neutrophil-bound cholesterol content were only partially restored by Flu. In addition, Flu had no effect on the increased membrane rigidity of the neutrophils of patients with hypercholesterolemia. To sum it up, Flu administration had a beneficial effect on AII-triggered reactive oxygen species generation; it resulted in partial restoration of signaling processes and of membrane composition, but membrane fluidity remained unchanged.

Topics: Aged; Angiotensin II; Calcium; Cells, Cultured; Fatty Acids, Monounsaturated; Fluvastatin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Indoles; Leukotriene C4; Male; Membrane Fluidity; Middle Aged; Neutrophils; Reactive Oxygen Species; Respiratory Burst; Signal Transduction; Vasoconstrictor Agents

Angiotensin II (Ang II) is able to induce free radical generation in neutrophils, which is more elevated in neutrophils of patients with hypercholesterolemia (HC). In addition, the signal processing through angiotensin I (Ang I) receptors is altered. In present study, we compared the Ang II-triggered free radical generation of neutrophils obtained from patients with relatively isolated forms of metabolic syndrome (MS) with membrane-bound cholesterol content and membrane fluidity. We determined the enhancement of Ang II-induced superoxide anion and leukotriene C(4) (LTC(4)) generation, membrane fluidity and cell-bound cholesterol content of neutrophils obtained from 12 control subjects, 11 patients with obesity (Ob), 10 patients with type 2 diabetes mellitus (t2-DM) and 12 patients with HC. The alteration of signal processing was studied after preincubation with different inhibiting drugs. Superoxide anion, LTC(4) production and membrane rigidity were increased in the following order: control < Ob < t2-DM < HC. Both Ang II-induced superoxide anion and LTC(4) generation were decreased in control cells by pertussis toxin and fluvastatin (Flu), whereas in each patient group, mepacrin, verapamil and Flu were effective, suggesting alterations in signal pathways, which may be attributed to isoprenylation. The enhancement of superoxide anion and LTC(4) generation correlated significantly with membrane rigidity, independently from the experimental groups and membrane-bound cholesterol content. Membrane rigidity of neutrophils, obtained from patients with MS, plays a role in Ang II-induced free radical generation independent of intracellular cholesterol homeostasis.

Topics: Adult; Angiotensin I; Angiotensin II; Anticholesteremic Agents; Cholesterol; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Fatty Acids, Monounsaturated; Female; Fluvastatin; Homeostasis; Humans; Hypercholesterolemia; Indoles; Leukotriene C4; Male; Membrane Fluidity; Metabolic Syndrome; Middle Aged; Neutrophils; Pertussis Toxin; Protein Prenylation; Quinacrine; Signal Transduction; Superoxides; Vasoconstrictor Agents; Vasodilator Agents; Verapamil