TY - JOUR
T1 - Platelet microparticles and calcium homeostasis in acute coronary ischemias
AU - Katopodis, John N.
AU - Kolodny, Luciano
AU - Jy, Wenche
AU - Horstman, Lawrence L.
AU - De Marchena, E. J.
AU - Tao, Jian G.
AU - Haynes, Duncan H.
AU - Ahn, Yeon S.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1997
Y1 - 1997
N2 - Elevation of free cytoplasmic calcium is the common pathway of platelet activation, leading to shape change, shedding of platelet microparticles (PMP), aggregation, and secretion of internal granules, including expression of CD62p on the surface. Platelet activation is well documented in unstable angina (UA) and acute myocardial infarction (MI). We investigated the following markers of platelet activation in 55 patients undergoing coronary angiography for suspected CAD: free cytoplasmic calcium, [Ca2+](cyt), PMP, CD62p expression, and platelet/leukocyte (P/L) interaction. [Ca2+](cyt) was measured by Fluo-3 and the other measurements were by flow cytometry. Patients were classified into three groups: unstable angina (UA, n = 11), recent myocardial infarction (MI, n = 11), and patient controls (CTL, n = 33). Blood was drawn before infusion of heparin through femoral lines at the time of catheterization for assays. Results: (1) PMP values were significantly higher in both UA and MI than in CTL, P < 0.05. There was no difference between UA and MI. (2) P/L interaction was significantly elevated only in UA, P < 0.05. (3) CD62p expression on free platelets did not differ significantly between any of the three groups. (4) The resting [Ca2+](cyt), thrombin-induced Ca2+ influx, and release of Ca2+ from internal stores were all significantly higher in platelets from the combined patient group (UA + MI) than in the patient control group, P < 0.001. Conclusions: Results on calcium hemostasis and PMP were significantly different in patients with acute coronary syndromes than those with stable angina or no coronary ischemia; this may reflect underlying pathophysiology of acute coronary ischemia. P/L interaction was higher only in the UA group, suggesting a role of leukocytes in UA.
AB - Elevation of free cytoplasmic calcium is the common pathway of platelet activation, leading to shape change, shedding of platelet microparticles (PMP), aggregation, and secretion of internal granules, including expression of CD62p on the surface. Platelet activation is well documented in unstable angina (UA) and acute myocardial infarction (MI). We investigated the following markers of platelet activation in 55 patients undergoing coronary angiography for suspected CAD: free cytoplasmic calcium, [Ca2+](cyt), PMP, CD62p expression, and platelet/leukocyte (P/L) interaction. [Ca2+](cyt) was measured by Fluo-3 and the other measurements were by flow cytometry. Patients were classified into three groups: unstable angina (UA, n = 11), recent myocardial infarction (MI, n = 11), and patient controls (CTL, n = 33). Blood was drawn before infusion of heparin through femoral lines at the time of catheterization for assays. Results: (1) PMP values were significantly higher in both UA and MI than in CTL, P < 0.05. There was no difference between UA and MI. (2) P/L interaction was significantly elevated only in UA, P < 0.05. (3) CD62p expression on free platelets did not differ significantly between any of the three groups. (4) The resting [Ca2+](cyt), thrombin-induced Ca2+ influx, and release of Ca2+ from internal stores were all significantly higher in platelets from the combined patient group (UA + MI) than in the patient control group, P < 0.001. Conclusions: Results on calcium hemostasis and PMP were significantly different in patients with acute coronary syndromes than those with stable angina or no coronary ischemia; this may reflect underlying pathophysiology of acute coronary ischemia. P/L interaction was higher only in the UA group, suggesting a role of leukocytes in UA.
KW - calcium homeostasis
KW - immune thrombocytopenic purpura (ITP)
KW - myocardial infarction
KW - platelet microparticles
KW - unstable angina
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U2 - 10.1002/(SICI)1096-8652(199702)54:2<95::AID-AJH1>3.0.CO;2-Z
DO - 10.1002/(SICI)1096-8652(199702)54:2<95::AID-AJH1>3.0.CO;2-Z
M3 - Article
C2 - 9034282
AN - SCOPUS:0031048761
VL - 54
SP - 95
EP - 101
JO - American Journal of Hematology
JF - American Journal of Hematology
SN - 0361-8609
IS - 2
ER -