Sensitivity of platelets to prostaglandins in cornary heart disease and angina pectoris.

The platelet sensitivity to the antiaggregatory prostaglandins (PGI2, PGE1 and PGD2) was studied in patients with angiographically verified coronary heart disease. The sensitivity was tested in vitro by inhibiting the ADP-induced platelet aggregation by various concentrations of these prostaglandins. Beside the age dependent alterations of platelet sensitivity reported earlier, there is a statistically significant decrease in sensitivity for PGI2 and PGE1 in patients with coronary heart disease. In contrast, no significant change for the PGD2-sensitivity could be observed. In angina pectoris a further significant decrease in sensitivity (again only for PGE1 and PGI2) was found which returned back to the starting values within a few hours. In patients with maturity onset diabetes and coronary heart disease the sensitivity was always lower than in those patients with coronary heart disease alone. Changes in platelet sensitivity might play a key role in initiating and progressing atherosclerosis by an immediate disturbance of hemostatic balance. The studies further support the hypothesis that PGI2 and PGE1 share the same receptor on the platelet surface.