[The effect of neonatal thymectomy on thrombocytopoesis in rats].

The influence of neonatal thymectomy on the number of thrombocytes, bone-marrow megakaryocytes (MKC) and activity of plasa thrombocytopoietin(TP) was studied in male rats 60 days after the manipulation--under normal and extreme (acute thromobocytopenia) conditions. It was established that under normal conditions neonatal thymectomy (NT) diminished the number of thromobocytes, the percentage of incorporated 75 selenomethionine in newly formed thromobocytes, the total number of MKC and their single stages--I, II, III, IV. The activity of plasma TP was not changed in normally thymectomized rats under normal condition, while in comparison with sham thymectomized rats, while it was considerably higher in acute thrombocytopenia. It is concluded that NT in rats inhibits megakarytocytopoiesis and diminishes thromobocyteson on this basis. NT stimulates biogenesis of TP- a specific humoral regulator of thrombocytopoiesis under conditions of acute thrombocytopenia.