[Effects of low-dose acetylsalicylic acid on thrombocytes in health subjects and in patients with coronary heart disease].

The effects on platelet function of a four-week administration of aspirin at a low dosage (100 mg daily) were compared in two groups, 14 healthy young volunteers and 14 patients with coronary heart disease. In both groups there occurred a clear inhibition of platelet aggregation with collagen (1 and 5 micrograms/l) and arachidonic acid (1 mmol/l) during the aspirin period. The inhibitory effect reached its maximum after three days, remaining at maximum for the remainder of the four weeks. Platelet functions returned to normal within eight days of discontinuing aspirin. The inhibitory effects went together with a definite in-vitro decrease in thromboxane synthesis. In both groups there was no change in aggregation velocity with adenosine diphosphate (ADP) as aggregation-inducing substance, while the frequency of irreversible aggregation decreased with submaximal concentrations of ADP (0.5 and 1.0 mumol/l). The results indicate that low-dose aspirin causes a definite inhibition of platelet function, in a similar manner, in both healthy subjects and patients with coronary heart disease.