title: Treadmill exercise in claudicants on aspirin results in improved antioxidant status but only minimal platelet activation.
abstract: The consequence of exercise on platelets remains controversial and adverse effects may result from repeated ischaemia reperfusion injury. We investigated platelet activation (platelet P-selectin (PS), and activated glycoprotein (Gp) IIb/IIIa), platelet-monocyte aggregates (PMA) and total plasma antioxidant status (TPAS) in claudicants after exercise. Twenty claudicants, taking 75 mg of aspirin daily, were subjected to repeated treadmill testing (3 km/h, 10% inclination). Blood was sampled before and after exercise. Activated GpIIb/IIIa, PS and PMA were quantified with flow cytometry. TPAS was quantified using a decolourisation assay. Percent positive cells for PS (pre-exercise 3.76% vs. 40 min post-exercise 4.10%; P < 0.05) and platelet-monocyte aggregates (pre-exercise: 25.31% vs. 40 min post-exercise 26.99%; P < 0.05) were significantly higher after exercise. Relative median fluorescence (RMF) for activated GpIIb/IIIa was significantly higher 40 min after exercise (pre-exercise: 3.04 vs. 40 min post-exercise: 4.01; P < 0.05). TPAS was significantly higher post-exercise (pre-exercise: 1.31 mmol/l vs. 1 min post-exercise: 1.40 mmol/l and 40 min post-exercise: 1.38 mmol/l; P < 0.01). Following moderate exercise, 'aspirin treated claudicants' show marginal platelet activation, PMA formation and a favourable improvement in antioxidant status. Further studies are required to assess the effect of additional antiplatelet agents and the significance of platelet-monocyte interactions. The possibility that aspirin contributes to the TPAS changes following exercise needs to be investigated.
authors.affiliation: Department of Vascular Surgery, Queen Elizabeth II Hospital, Gateshead, UK.
authors.forename: M
authors.initials: M
authors.lastname: Cleanthis
authors.forename: J
authors.initials: J
authors.lastname: Smout
authors.forename: V
authors.initials: V
authors.lastname: Bhattacharya
authors.forename: H
authors.initials: H
authors.lastname: Ashour
authors.forename: B
authors.initials: B
authors.lastname: Shenton
authors.forename: G
authors.initials: G
authors.lastname: Stansby
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000032:analysis; D001241:Aspirin / Q000008:administration & dosage*; D016022:Case-Control Studies; D005080:Exercise Test / Q000009:adverse effects; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction / Q000187:drug effects; D019007:P-Selectin / Q000097:blood; D010636:Phenols; D010936:Plant Extracts; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000032:analysis; D015427:Reperfusion Injury / Q000097:blood* / Q000209:etiology
chemical_list: D000975:Antioxidants; D019007:P-Selectin; D010636:Phenols; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C501911:antioxidant biofactor AOB; D001241:Aspirin