Cardiovascular research
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Cardiovascular research · Aug 2000
Comparative StudyComparative study of AMP579 and adenosine in inhibition of neutrophil-mediated vascular and myocardial injury during 24 h of reperfusion.
The purpose of this study was to compare protective effects of AMP579 and adenosine (Ado) at reperfusion (R) on inhibition of polymorphonuclear neutrophil (PMN) activation, PMN-mediated injury to coronary artery endothelium, and final infarct size. ⋯ These data suggest that continuous infusion of AMP579 at R is more potent than adenosine in attenuating R injury, and AMP579-induced cardioprotection involves inhibition of PMN-induced vascular and myocardial tissue injury. *P<0.05 vs. Control.
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Cardiovascular research · Aug 2000
Modulation of intrinsic cardiac neurons by spinal cord stimulation: implications for its therapeutic use in angina pectoris.
Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with severe angina pectoris refractory to conventional therapeutic strategies. Clinical studies show that spinal cord stimulation (SCS) is a safe adjunct therapy for cardiac patients, producing anti-anginal as well as anti-ischemic effects. However, little information is yet available about the underlying mechanisms involved. ⋯ SCS modifies the capacity of intrinsic cardiac neurons to generate activity. SCS also acts to suppress the excitatory effects that local myocardial ischemia exerts on such neurons. Since no significant changes in monitored cardiovascular indices were observed during SCS, it is concluded that modulation of the intrinsic cardiac nervous system might contribute to the therapeutic effects of SCS in patients with angina pectoris.
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Cardiovascular research · Nov 1999
Alterations in c-fos expression, cell proliferation and apoptosis in pressure distended human saphenous vein.
Saphenous vein graft failures, resulting from thrombosis and the abnormal proliferation, migration and apoptosis of vascular smooth muscle cells (VSMC) are major limitations of coronary artery bypass surgery. We investigated whether surgical trauma of human saphenous vein induces the early response gene c-fos and causes alterations in rates of proliferation and apoptosis. ⋯ These findings demonstrate that surgical preparation of human saphenous vein increases expression of c-fos mRNA and apoptosis and reduces proliferation when compared with non-distended vein. These changes may influence the failure of saphenous vein grafts.
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Cardiovascular research · Oct 1999
Effects of the calcium channel antagonist mibefradil on haemodynamic parameters and myocardial Ca(2+)-handling in infarct-induced heart failure in rats.
Abnormal intracellular Ca(2+)-handling has been implicated in the pathogenesis of contractile dysfunction and arrhythmias in failing hearts. Calcium channel antagonists (CCA) have been proposed for the prevention of cardiac events after myocardial infarction (MI). Recent studies suggest that the blockade of T-type Ca(2+)-channels induced a heart rate reduction without negative inotropic effects. We investigated the effects of the preferentially T-channel blocking CCA, mibefradil, on haemodynamic parameters and intramyocardial Ca(2+)-handling and contractility in the early and late period after MI. ⋯ We conclude, that mibefradil improves cardiac function, protects the myocardium against ischemia-induced Ca(2+)-overload and increases beta-adrenergic responsiveness in chronically failing rat hearts.