ABSTRACT
Platelets were isolated from the blood of rats fed on st and ard laboratory diets and rats fed on supplements of pyridoxal-5-phosphate [PLP] and polyunsaturated fatty acids [PUFA] alone or in combination. Platelet counts and their protein and total lipid content were unaltered by the regimes. Rats fed on PUFA showed a significant increase in the linoleic acid content of the phospholipid fraction of platelets [p <0.001]. Dietary supplementation for one week with PLP or PUFA alone or in combination significantly prolonged the clotting time of freshly drawn blood, decreased the extent of ADP-induced aggregation, the release of platelet 5-hydroxytryptamine [5-HT] and the formation of thromboxane B2 [TXB2]. Furthermore, platelets isolated from rats fed on dietary supplements were more sensitive to inhibition of aggregation by PLP in vitro, and their aggregation by collagen was not similarly affected. These results pointed to a direct and specific inhibitory action of PLP on ADP-induced aggregation of blood platelets