title: Inhibition of 5'-chloro-5'-deoxyadenosine on phosphoinositide and protein phosphorylation in swine platelets.
abstract: OBJECTIVE
  To study the effects of adenosine on the phosphorylation of phosphoinositides and proteins in platelets.
  
  
  METHODS
  In the presence of Mg2+ and/or Ca2+, swine thrombocytic membranes were incubated with [gamma-32P]ATP at 30 degrees C for 3 min and the incorporations of 32P into phospholipids or proteins were measured.
  
  
  RESULTS
  5'-Chloro-5'-deoxyadenosine decreased the formation of phosphatidylinositol 4-phosphate and phosphatidylinositol 4, 5-bisphosphate [IC50 71 and 75 (95% confidence limits 60-85 and 62-90) mumol.L-1, respectively], behaving as a competitive inhibitor to ATP, and inhibited the phosphorylation of pleckstrin (the major protein kinase C substrate) and myosin light chain [IC50 75 and 82 (95% confidence limits 62-90 and 66-102) mumol.L-1, respectively].
  
  
  CONCLUSIONS
  Adenosine affects the phosphoinositide signaling pathway in platelets, which helps to clarify the inhibition of adenosine on platelet activation.
authors.affiliation: Department of Biochemistry, Guangdong Medical College, Zhanjiang, China.
authors.forename: K H
authors.initials: KH
authors.lastname: Ding
authors.forename: N C
authors.initials: NC
authors.lastname: Liang
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D017338:Cladribine / Q000494:pharmacology*; D018994:Myosin Light Chains; D009218:Myosins / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates / Q000096:biosynthesis*; D010750:Phosphoproteins; D010766:Phosphorylation / Q000187:drug effects; D013552:Swine
chemical_list: D001798:Blood Proteins; D018994:Myosin Light Chains; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010750:Phosphoproteins; C076659:myosin light chain I; C037178:phosphatidylinositol 4-phosphate; C039077:platelet protein P47; D017338:Cladribine; C044739:5'-chloro-5'-deoxyadenosine; D009218:Myosins