title: Activated reptilase clot retraction of dog platelet-rich plasma: differences with human platelet-rich plasma.
abstract: The retraction of dog platelet-rich plasma (PRP) clotted with Reptilase in the presence of inducers and inhibitors of the platelet adhesion-aggregation reaction was studied. In contrast to human cells, dog platelets fail to support retraction in an ADP-Reptilase system. With Thrombofax as aggregation inducer, slight (without additional CaCl2-MgCl2) to moderate (with additional CaCl2-MgCl2) retraction occurs. In contrast to human samples, such retraction is inhibited by platelet release inhibitors. Electron-microscopic examinations show that Thrombofax, but not ADP, induces the formation of large cytoplasmic protrusions from dog platelets. Such formation is inhibited by release-inhibitors. The results of the study support the concept that platelet pseudopod formation, rather than the release reaction, is a prerequisite for clot retraction.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D012103:Batroxobin / Q000494:pharmacology*; D001792:Blood Platelets / Q000648:ultrastructure; D003018:Clot Retraction; D004285:Dogs / Q000097:blood*; D006801:Humans; D008854:Microscopy, Electron; D010447:Peptide Hydrolases / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D013268:Stimulation, Chemical; D013925:Thromboplastin / Q000494:pharmacology
chemical_list: D000244:Adenosine Diphosphate; D013925:Thromboplastin; D010447:Peptide Hydrolases; D012103:Batroxobin