Inhibition of 5'-chloro-5'-deoxyadenosine on phosphoinositide and protein phosphorylation in swine platelets
Ding, K.H.; Liang, N.C.
Zhongguo Yao Li Xue Bao 16(3): 247-250
1995
ISSN/ISBN: 0253-9756 PMID: 7660821 Document Number: 446760
AIM: To study the effects of adenosine on the phosphorylation of phosphoinositides and proteins in platelets. METHODS: In the presence of Mg-2+ and/or Ca-2+, swine thrombocytic membranes were incubated with (gamma-32P)ATP at 30 degree 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 (IC-50 71 and 75 (95% confidence limits 60-85 and 62-90) mu-mol cntdot 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 (IC-50 75 and 82 (95% confidence limits 62-90 and 66-102) mu-mol cntdot L-1, respectively). CONCLUSION: Adenosine affects the phosphoinositide signaling pathway in platelets, which helps to clarify the inhibition of adenosine on platelet activation.