RESUMO
The inhibitory effect of pyridoxal-5-phosphate [PLP] on gel filtered platelets [GFP] function has been studied. Prior addition of PLP caused inhibition of platelet aggregation and 5-HT, induced by ADP thrombin. The results showed no significant change in the formation of inositol triphosphate [IP3], due to phosphoinositides hydrolysis and of ADP induced platelets in the presence of PLP. ADP did not cause any decrease in the level of radioactivity of the phospholipids fraction nor an increase in the arachidonate metabolites from platelets treated with PLP. Prostagl and in synthetase activity was also examined and found to be not affected by PLP. The results also showed that PLP may exert its inhibitory effect by blocking the release of arachidonate but not its metabolism