Influences of various hormones on the megakaryocyte in bone-marrow tissue culture

In our study on the influences of various hormones and various endocrines on the megakaryocyte function by means of bone-marrow tissue culture, we obtained the following. 1. In the repeated administration of ACTH, cortisone, testosterone, progesterone, or thyroxin to guinea pigs, these hormones accelerated the megakaryocyte function, whereas estradiol on the contrary diminished the function. 2. The removal of such endocrines as the pituitary, adrenal, thyroid or testicles will diminish the megakaryocyte function, while removal of the ovaries accelerates it. 3. For the megakaryocytes in the hypophysectomized rats, ACTH acts most effectively to restore their function, followed by cortisone and pulverized thyroid, while testosterone has hardly any effect on the function. 4. ACTH, cortisone, prednisolone, testosterone, progesterone, and pulverized thyroid act directly on megakaryocytes so as to accelerate their function, while estradiol diminishes the megakaryocyte function. 5. For the megakaryocytes in idiopathic thrombocytopenic purpura ACTH is most effective in restoring the function; for the megakaryocytes in hypoplastic anemia cortisone is most effective; and for the megakaryocytes in Banti's disease prednisolone is most effective in restoring the megakaryocyte function.