Drug-Free Platelets Can Act as Seeds for Aggregate Formation During Antiplatelet Therapy

The online-only Data Supplement is available with this article at http://atvb.ahajournals.org/lookup/suppl/doi:10.1161/ATVBAHA.115.306219/-/DC1.Medical Research Council, the British Heart Foundation (PG-12-68-29779), the Wellcome Trust (101604/Z/13/Z), and the William Harvey Research Foundation. T.D. Warner has received research grant funding and consultancy fees from Astra Zenec

Chromatographic Techniques for the Separation of a Thrombocytopoiesis-Stimulating Factor from Aplastic Rats

Thrombocytopoietin seems to be only partially responsible for the regulation of platelet production. We determined precisely the differences between a second thrombocytopoiesis-stimulating factor (TSF&lt;sub&gt;2&lt;/sub&gt;), and thrombocytopoietin (TSF&lt;sub&gt;1&lt;/sub&gt;) and erythropoietin (Epo). Fractionation was carried out, first on a DEAE-cellulose phosphate column and then on a Sephadex G-75 column. Thrombocytopoietic activity in the various fractions was assessed using &lt;sup&gt;75&lt;/sup&gt;Se-methionine platelet incorporation into normal recipients. Epo concentrations were determined using a radioimmunoassay. We showed that the apparent molecular weight of TSF&lt;sub&gt;2&lt;/sub&gt; is 14,000 daltons. It differs from TSF&lt;sub&gt;1&lt;/sub&gt; (48,000 daltons) and from Epo (39,000 daltons). For doses of 8–12 mU Epo/rat, found in whole serum injected, no effect on thrombocytopoiesis was found. On the contrary, a significant effect (p &lt; 0.01) was found when the same quantities of Epo present in the Sephadex G-75 F4’ fraction were injected (2–10 mU/rat). TSF&lt;sub&gt;2&lt;/sub&gt; can be separated from TSF&lt;sub&gt;1&lt;/sub&gt; and Epo, using biochemical techniques.</jats:p