Thromb Haemost 1997; 78(06): 1505-1509
DOI: 10.1055/s-0038-1665442
Rapid Communication
Schattauer GmbH Stuttgart

Erythropoietin Administration Increases Production and Reactivity of Platelets in Dogs

Roman F Wolf
The Department of Medicine and W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
,
Jinpeng Peng
The Department of Medicine and W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
,
Paul Friese
The Department of Medicine and W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
,
Laura S Gilmore
The Department of Medicine and W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
,
Samuel A Burstein
The Department of Medicine and W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
,
George L Dale
The Department of Medicine and W. K. Warren Medical Research Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
› Author Affiliations
Further Information

Publication History

Received 11 1997

Accepted 11 July 1997

Publication Date:
12 July 2018 (online)

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Summary

Administration of erythropoietin (EPO) to adult dogs resulted in a dramatic increase in the number of thiazole orange-positive (TO+) platelets, also referred to as reticulated platelets. Pre-treatment level of TO+ platelets was 6.2 ± 0.5% (mean ± 1 SE; n = 5); following day 5 of treatment with 500 U EPO/kg/day, the percentage of TO+ platelets peaked at 16.8 ± 2.3% (n = 5; p <0.02). After cessation of the hormone, the number of TO+ platelets fell rapidly to below starting levels. Unexpectedly, there was a significant decline in total platelet count during EPO administration despite an increased level of TO+ platelets. To assess platelet reactivity, total platelets and TO+ platelets from EPO- treated dogs were analyzed for thrombin-responsiveness as quantitated by P-selectin expression on the cell surface; reactivity was expressed as a thrombin EC50, the thrombin concentration required to activate 50% of platelets. Both total and TO+ platelets were hyperreactive during EPO treatment when compared either to pre-treatment values or to control animals. Thrombin EC50 values for total and TO+ platelets on day 5 fell to 66.5 ± 5.4% (mean ± 1 SE; n = 5; p <0.02) and 62.2 ± 8.7% (n = 5; p <0.025), respectively, of pre-treatment levels. These data indicate that EPO not only promotes the synthesis of increased numbers of TO+ platelets in the dog but that these newly produced platelets are hyperreactive when compared to TO+ platelets from control animals.