title: PDGF modifies phosphoinositide metabolism and inhibits aggregation and release in human platelets.
abstract: While platelet derived growth factor (PDGF) did not induce any platelet aggregation nor secretion, it modified the polyphosphoinositide metabolism of human platelets prelabeled with 32P-orthophosphate. We found a decrease of 32P associated with phosphatidylinositol 4,5 bisphosphate after 3 min, with parallel increase of 32P-phosphatidylinositol 4 phosphate and 32P-phosphatidylinositol using 100 ng/ml of PDGF. This modification was PDGF concentration dependent. PDGF inhibited thrombin and collagen induced platelet aggregation and 14C-serotonin release in a dose dependent manner, but was without effect when arachidonic acid was used. These results suggest that PDGF (i) stimulated the hydrolysis of polyphosphoinositides (ii) and could exert a negative feedback control on platelet activation induced by thrombin or collagen.
mesh_terms: D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects*; D003094:Collagen / Q000494:pharmacology; D006801:Humans; D010716:Phosphatidylinositols / Q000097:blood*; D010974:Platelet Aggregation / Q000187:drug effects*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D012636:Secretory Rate / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology
chemical_list: D001095:Arachidonic Acids; D010716:Phosphatidylinositols; D010982:Platelet-Derived Growth Factor; D016718:Arachidonic Acid; D012701:Serotonin; D003094:Collagen; D013917:Thrombin