INHIBITION EFFECTS OF ADENOSINE AND ITS ANALOGUES ON ACTIN POLYMERIZATION IN PIG PLATELETS AND THE POSSIBLE MECHANISM
Huang Cai Liang Nian-ci (Department of Medical Biochemistry, Guangdong Medical College, Zhanjiang 524023)
The effects of adenosine and its analogues on the polymerization of actin in pig platelets and the possible mechanism were investigated. The results show that: Thrombin (0.5 U/ml) and ADP (50 μmol/ L) stimulate actin polymerization in pig platelets; Adenosine, 5'-chloro-5'-deoxya-denosine, 2'-deoxyadenosine strongly inhibit thrombin- and/or ADP-induced actin polymerization. Adenosine and 5'-chloro-5'-deoxyadenosine strongly inhibit the phosphorylation of phosphatidylinositol in dose-dependent manner, and adenosine reverses the formation of thrombin-stimulated inositol bisphosphate, which has proved to promote the polymerization of actin in saponin-permeated platelets. These suggest that the inhibition of adenosine and its analogues on phosphatidylinositol turnover might involve in their inhibition on actin polymerization in platelets, and phosphatidylinositol turnover might play an important role in actin polymerization during cell activation.