Soluble L-selectin and neutrophil derived oxidative stress after pacing induced myocardial ischemia in chronic stable coronary artery disease.
ABSTRACT We studied the effect of atrial pacing induced myocardial ischemia on levels of soluble L-selectin (sL-selectin) and generation of neutrophil derived reactive oxygen species (ROS) in 10 patients with coronary artery disease (CAD) and stable angina and in six individuals without CAD. Myocardial ischemia was measured metabolically by lactate sampling from the coronary sinus (CS) and arterial blood at each pacing step. Before each pacing step, at peak pacing and shortly after cessation, plasma concentrations of sL-selectin and generation of ROS using the chemiluminescence method were measured in CS and femoral artery blood. Baseline sL-selectin levels in CS samples were significantly lower in the CAD compared to the control group (547 +/- 80 vs 836 +/- 82 ng/mL, P = 0.03). At peak pacing, nine of ten patients with CAD developed myocardial ischemia (lactate extraction ratio at rest 28% +/- 7%, at peak pacing -16% +/- 6%). In these patients, luminol-enhanced chemiluminescence (CL, 0.88 +/- 0.45 vs 1.9 +/- 0.9 cpm x 10(5), P = 0.09) and levels of sL-selectin (547 +/- 80 vs 764 +/- 86 ng/mL, P = 0.03) from naive neutrophils increased significantly in CS blood suggesting a potent in vivo activation of neutrophils. In control patients, incremental pacing caused neither myocardial ischemia nor a significant change of chemiluminescence or of sL-selectin levels. In conclusion, myocardial ischemia induced by pacing tachycardia is able to activate neutrophils in patients with chronic stable coronary artery disease leading to increased generation of ROS and shedding of L-selectin into the coronary circulation.
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ABSTRACT: Cardiovascular disease constitutes a major public health concern in industrialized nations. Over recent decades, a large body of evidence has accumulated indicating that oxidative stress induced free radicals play a critical role in cellular processes implicated in atherosclerosis and many other heart diseases. However a diet high in antioxidants is associated with a reduced risk of cardiovascular disease. The compound quercetin is a dietary antioxidant with a polyphenolic structure that is present in many foods, such as onion, apples, wine and tea. An increased intake of quercetin has been correlated with a decrease in the risk of cardiovascular diseases. Quercetin has been reported to exhibit a wide range of biological and pharmacological effects in animals and man besides its antioxidative and free radical scavenging actions. This paper reviews various steps of oxidative stress mediated atherogenesis and their signaling pathways and also emphasizes the role of quercetin in controlling oxidative stress and reducing the incidence of cardiovascular diseases.Internet Journal of Medical Update. 01/2008;