Megakaryocyte and Platelet Production in Normal Dogs and Dogs Subjected to Three Types of Marrow Stress

摘要

Experimental studies on megakaryocytes and platelets were performed on normal dogs, hormone (testosterone, Premarin, and estrone) treated dogs, acutely bled dogs and dogs exposed to LD 36/30 doses of X-Rays. The irradiation studies included whole body and partial body exposures. Parameters of investigation included enumeration and classification of megakaryocytes in aspirated bone marrow specimens and enumeration and volume measurements of the peripheral blood platelets. The methods developed for megakaryocyte enumeration and platelet volume analysis are presented. A morphological classification system, suitable for the dog megakaryocytes is presented with the aid of photomicrographs. Estrone, a non-water soluble, non-conjugated estrogen preparation, given in daily doses of 0.08 to 0.10 mgm/kg body weight for 21 days, produced marked platelet depression after 20 days of treatment. From the 26th to the 33rd day after initiation of treatment, bizarre megakaryocytes appeared in the bone marrow samples. These are likened to bizarre forms reported in tropical sprue. A transient influx of large platelets in the peripheral blood was concomitant with the megakaryocyte abnormalities. At this time, also, there was almost total absence of nucleated erythroid elements in the bone marrow. (Author)