The effect of ageing on platelet function and fibrinolytic activity.
Twelve healthy male volunteers, mean age twenty-five, range twenty-one to thirty years, and 12 healthy middle-aged male volunteers mean age fifty-eight, range forty-four to seventy-two years, were tested regarding platelet aggregation induced by adenosine diphosphate and fibrinolytic activity, estimated as euglobulin clot lysis time (ECLT), tissue plasminogen activator (t-PA), and the fast-acting inhibitor against t-PA normally referred to as (PAI-1). Platelet aggregation increased significantly in the middle-aged group as compared with the young, as shown by a decrease in ADP thresholds for irreversible aggregation (P < 0.01). In healthy young volunteers, vigorous cycling exercise by itself caused platelet aggregability to decrease (P < 0.05). Such changes were not observed in the elderly. Fibrinolytic activity decreased significantly in the middle-aged group as shown by a prolongation of the ECLT (P < 0.01) and PAI-1, although not significantly, increased by approximately 100%, whereas t-PA significantly increased in the middle-aged group (P < 0.01). The present results suggest that increasing age is associated with not only increased platelet aggregability but also decreased fibrinolytic activity.
Gleerup
G
G
Department of Cardiology, Glostrup Hospital, Copenhagen, Denmark.
Winther
K
K
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood*; D005342:Fibrinolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D010974:Platelet Aggregation / Q000187:drug effects; D010959:Tissue Plasminogen Activator / Q000097:blood
D017395:Plasminogen Activator Inhibitor 1; D000244:Adenosine Diphosphate; D010959:Tissue Plasminogen Activator