There are many substances effecting on the platelet aggregation. But the detail mechanism of platelet aggregation is unknown yet.
We observed many substances which have the effect on platelet aggregation. Consequently, we found two interesting substances which have similar chemical composition with Vitamin E. The effects of these substances on platelet aggregation (human platelets) were studied with Evans's aggregometer. 6-Hydroxy 2, 5, 7, 8, tetramethyl chroman-2-carboxylic acid (vitamin E analog) inhibited platelet aggregation induced by noradrenaline (55.5γ/ml), ADP (55.5γ/ml) and arachidonic acid (555.5γ/ml). But it didn't inhibit the aggregation induced by collagen (22.2γ/ml) or 0.5μ/ml of thrombin.
On the other hand, dl-α-Tocopherol diphosphoric acid ester induced the platelet aggregation by itself. The aggregating ability of 100γ/ml-150γ/ml of dl-α-Tocopherol diphosphoric acid ester is as same as ADP (555.5γ/ml). Its molecular weight is almost as same as ADP. So the ability of aggregation of this substance is one half of that of ADP. Vitamin Eis known as antioxidative agent. Though these substances have similar structure to Vitamin E, 6-Hydroxy, 2, 5, 7, 8, tetramethyl chroman-2-carboxylic acid inhibited platelet aggregation, while dl-α-Thcopherol diphoric acid ester initated the aggregation.
From these results obtained, it might be difficult to explain the difference between Vitamin E and substances examined.