Serial changes of natural antithrombotics during myocardial ischemia-reperfusion in swine. Effects of magnesium, diltiazem, and a novel Mac-1 inhibitor.
Plasma antithrombin-III (AT-III), protein S, and protein C were measured during myocardial stunning (MS) and acute myocardial infarction (AMI). The effects of magnesium (Mg), diltiazem, and a Mac-1 inhibitor on their plasma levels were elucidated. Forty-nine open-chest swine underwent brief (8 min) or prolonged (50 min) coronary artery occlusion followed by reperfusion. During MS an increase in the plasma AT-III (from 98.5 +/- 3.38% to 138.1 +/- 3.6%) during the early occlusion phase, without any further changes was observed. The profile of total protein S was not changed during MS. Protein C increased at the end of occlusion (from 45.3 +/- 1.8% to 55.7 +/- 1.4%) reaching a peak (64.5 +/- 1.4%) at the beginning of reperfusion. When compared with controls, no significant differences were found in the antithrombotics profile during MS after pretreatment with Mac-1 inhibitor. For the AMI, the AT-III decreased during occlusion (from 98.5 +/- 3.4% to 61.0 +/- 3.6%). The protein S decreased during occlusion with the lowest level at 1 h of reperfusion (from 71.8 +/- 2.2% to 46.7 +/- 1.0%), followed by an increase during late reperfusion (59.2 +/- 1.5%). Contrarily, protein C increased during occlusion and early reperfusion (from 44.7 +/- 2.6% to 79.4 +/- 2.4%), but declined to 49.6 +/- 2.5% thereafter. In both Mg and diltiazem-treated swine, protein C was higher at the end of occlusion and during the entire reperfusion period compared with controls. Mg and diltiazem therapy was associated with the slight elevation of plasma AT-III. The patterns for protein S level during ischemia-reperfusion were similar with the controls. Protein S was higher at the end of occlusion and through the entire reperfusion in the NPC 15669-treated animals when compared with the controls. Mac-1 inhibition was associated with the elevated protein C during late reperfusion. Ability of Mg, diltiazem, and Mac-1 inhibitor to favorably modulate the plasma level of antithrombotics have direct clinical implications for the use of these agents in patients with acute coronary artery syndromes.
Serebruany
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VL
Heart Associates Research and Education Foundation, Union Memorial Hospital, Baltimore, MD 21218, USA.
Herzog
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WR
Gurbel
P A
PA
D000818:Animals; D000991:Antithrombins / Q000378:metabolism*; D004110:Diltiazem / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D016177:Macrophage-1 Antigen / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology*; D009203:Myocardial Infarction / Q000378:metabolism; D015425:Myocardial Reperfusion; D017682:Myocardial Stunning; D009206:Myocardium / Q000378:metabolism*; D013552:Swine; D014969:Xanthine Oxidase / Q000378:metabolism
D000991:Antithrombins; D016177:Macrophage-1 Antigen; D014969:Xanthine Oxidase; D004110:Diltiazem; D008274:Magnesium