[The effect of 2 thrombocytopoietic-active polypeptides on thrombocytopenia in mice irradiated with ionizing...

The assumption that thrombocytopoietin preparations prepared in our own laboratory can prevent the decrease of the number of thrombocytes in the peripheral blood of animals irradiated by a sublethal dose of gamma-ionizing rays was tested in an experiment on mice. Two preparations were tested: one, with an influence on stem cells, which directs them in the direction of megacariocyte differentiation (Smp), and the other one which is essential for the endomitosis and production of thrombocytes (Stp). The results undoubtedly indicated that a decrease in the number of thrombocytes occurred in the peripheral blood of animals following irradiation without the use of the preparations mentioned above, and was mostly emphasized after 9 days. The fact that was also demonstrated was that this decrease is significantly lesser if the animals are treated, after irradiation, with both preparations together or only with preparation Stp which has an influence on the directed thrombocytopoiesis cells, while the preparation Smp does not show such an effect. On the basis of these results a conclusion was made that thrombocytopenia of irradiated subjects sets on as a consequence of a temporary lack of one of the two poietins of thrombocytopoiesis, meaning Stp, which can be of importance in the treatment of the acute radiation syndrome in man.