ABSTRACT
AIM: To investigate effects of thrombopoietin(TPO) and TPOⅡ on human platelet activation in vitro. METHODS:Human platelets were incubated in the phosphate-buffered saline containing rhTPO or TPOⅡ at the concentration of 100 ?g/L for five minutes. In order to determine the rate of platelet activation. The CD62P and CD41 expressions on platelets were analysed by flow cytometry using fluorescence labelled monoclonal antibody to CD62P and CD41. RESULTS: The results demonstrated that expression of CD62P on platelets which were incubated with rhTPO or TPOⅡ didn't increase compared with that of contrast group. CONCLUSION: Both rhTPO and TPOⅡdidn't cause the disorder of platelet activation.
ABSTRACT
AIM: To investigate the biological activity of thrombopoietin Ⅱ(TPOⅡ) in vivo , which consists of two new kinds of ligand binding with thrombopoietin receptor. METHODS: Purified ligandⅠof TPOⅡ, artificial compound ligandⅡ of TPOⅡand rhTPO were injected into purebred Babl/c mice respectively in 7 days by intraperitoneal injection once for a day. Then the biological activity of TPOⅡ was analyzed by measuring peripheral platelet counts by the end of the seventh day. RESULTS: On the seventh day, the platelet counts of mice treated by ligandⅠof TPOⅡ were higher than that in the negative control group( P 0.05). On the fourteenth day, the platelet counts increased in two all experimental groups of TPOⅡcompared with negative control group( P 0.05). Moreover the platelet counts of mice in two experimental groups of TPOⅡ and the positive group showed increase with experimental days. CONCLUSION: The purified ligandⅠof TPOⅡ had obvious activity in increasing platelet production, which is not different from the effect of rhTPO.