title: Reverse relationship between mitogen activated protein kinase and human platelet aggregation.
abstract: The role of MAPK in platelets was investigated. In human platelets maintained at 4 degrees C for 2 hr, the MAPK activity increased (approximately 2 fold) when compared to those maintained at 37 degrees C. When aggregation was monitored under these conditions, the platelets maintained at 4 degrees C or 15 degrees C showed an 85% and 71% decrease respectively to thrombin (0.5 U/ml for 1 min) induced aggregation. When the platelet cytosol was maintained at 4 degrees C and assayed for MAPK activity, the MAPK activity decreased significantly, indicating that the observed effects are seen in intact platelets only, and are not due to temperature effects on the assay. When platelets maintained at 4 degrees C or 15 degrees C (for 2 hrs) were transferred to 37 degrees C, the MAPK activity decreased to levels observed in platelets maintained throughout at 37 degrees C and was thus reversible. Therefore, it is concluded that a possible reverse relationship between MAPK and platelet aggregation plays a role in platelet responses.
authors.affiliation: Department of Pharmacology, School of Medicine, University of Missouri-Columbia, 65212, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Kansra
authors.forename: S D
authors.initials: SD
authors.lastname: Shukla
mesh_terms: D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D003600:Cytosol / Q000378:metabolism; D006490:Hemostatics / Q000494:pharmacology; D006801:Humans; D020014:K562 Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology*; D013696:Temperature; D013917:Thrombin / Q000494:pharmacology
chemical_list: D006490:Hemostatics; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin