RESUMO
1. The anti-aggregatory potency of a number of E-type PGs was compared in human and rabbit platelet-rich plasma (PRP) and washed platelets. The potency of 13,14-dihydro-PGE1 and 5,6-dihydro-PGE3 is significantly higher in human than in rabbit washed platelets, while the potency of 15-keto-13,14-dihydro-PGE1 is higher in rabbit. 2. The potency of PGEs in rabbit PRP is very similar to that of washed platelets, with the exception of 1a,1b-dihomo-PGE2, which is of a significantly lower potency in PRR. 3. In human, 5,6-trans-PGE2, PGE3, and 15-keto-13,14-dihydro-PGE1 are more potent in PRP than in washed platelets. 4. The results indicate that the potency of E-type PGs in human and rabbit platelets is different and plasma can essentially influence the anti-aggregatory effect of PGEs; plasma can either decrease or increase potency.
Assuntos
Epoprostenol/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Prostaglandinas E/farmacologia , Difosfato de Adenosina/farmacologia , Animais , Feminino , Humanos , Masculino , Inibidores da Agregação Plaquetária/farmacologia , CoelhosRESUMO
Prostaglandin biosynthetic activity of cultured human aortic and umbilical vein endothelial cells (passages 3-9) and of human aortic subendothelial cells (passage 0) was studied. Labelled arachidonic acid or endoperoxide H2 (final concentrations, 10 microM and 3.5 microM, respectively) were used as prostaglandin synthesis precursors. Arachidonic acid metabolites released into the incubation medium were separated by thin-layer chromatography and assayed for radioactivity. It has been demonstrated that endothelial and subendothelial cells in culture synthesize, besides prostacyclin, significant quantities of other prostaglandins, such as PGF2, PGE2, as well as thromboxane B2.
