title: Action of phosphatidylinositol specific phospholipase C on platelets: nonlytic release of acetylcholinesterase, effect on thrombin and PAF induced aggregation.
abstract: Phosphatidylinositol (PI) specific phospholipase C treatment of rabbit platelets caused 95% release of acetylcholinesterase in the supernatant and 4 to 6% hydrolysis of membrane PI in 2 min. Under these conditions there was no cell lysis as monitored by lack of lactate dehydrogenase activity in the medium. The phospholipase C had no activity towards phosphatidylinositol-4- phosphate and phosphatidylinositol-4,5-bis phosphate. Platelets pretreated with the phospholipase C responded normally to thrombin and platelet activating factor. It is concluded that acetylcholinesterase exists in specific interaction with PI in platelet membranes. Further, the membrane protein release phenomenon caused by the PI-specific phospholipase C did not effect the physiological responsiveness of platelets. Possible implications of these findings to the linkage between PI and membrane enzyme are also discussed.
mesh_terms: D000110:Acetylcholinesterase / Q000097:blood*; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D007700:Kinetics; D010716:Phosphatidylinositols / Q000097:blood*; D010972:Platelet Activating Factor / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D011817:Rabbits; D013211:Staphylococcus aureus / Q000201:enzymology; D013917:Thrombin / Q000494:pharmacology; D010738:Type C Phospholipases / Q000494:pharmacology*
chemical_list: D010716:Phosphatidylinositols; D010972:Platelet Activating Factor; D000110:Acetylcholinesterase; D010738:Type C Phospholipases; D013917:Thrombin