Influence of nonselective beta-adrenergic impacts on the effects of thrombocytopoietin in mice.

The effects of plasma thrombocytopoietin are investigated in test mice against the background of nonselective beta adrenergic impacts. The changes in the thrombocytopoiesis are accounted for by the thrombocytes count and by the percentage of 75selenomethionine incorporated in the newly-formed thrombocytes. Plasma thrombocytopoietin is found to stimulate markedly thrombocytopoiesis on the background of beta-adrenergic stimulation with isoprenaline. Pretreatment with propranolol totally prevents this stimulation. Independent treatment with propranolol as a background of thrombocytopoietin considerably inhibits thrombocytopoiesis. The effects of thrombocytopoietin are found to depend on the state of the beta-adrenoreceptors: their stimulation has a synergic effect on thrombocytopoietin, while their blocking impedes its realization. The data established are indirect proof about the existence of beta-adrenoreceptors in the megakaryocyte series and probably in its precursors as well.